Integrated Taxonomic Information System - Taxon Author Search Results

Publication: Turgeon, D. D., J. F. Quinn, Jr., A. E. Bogan, E. V. Coan, F. G. Hochberg, W. G. Lyons, et al. 1998 Common and scientific names of aquatic invertebrates from the United States and Canada: Mollusks, 2nd ed. American Fisheries Society Special Publication 26 526

ITIS records citing this publication
 
 Kingdom Animalia
  Abra Lamarck, 1818 -- valid
  Abra aequalis (Say, 1822) -- valid -- Atlantic abra
  Abra lioica (Dall, 1881) -- valid -- smooth abra
  Abra longicallis Sacchi, 1836 -- valid -- long abra
  Abra longicallis americana A. E. Verrill and Bush, 1898 -- valid -- long abra
  Acanthina Fischer de Waldheim, 1807 -- valid
  Acanthina lugubris (G. B. Sowerby I, 1821) -- valid -- dark unicorn
  Acanthina paucilirata (Stearns, 1871) -- valid -- checkered unicorn
  Acanthina punctulata (G. B. Sowerby I, 1825) -- valid -- spotted unicorn
  Acanthina spirata (de Blainville, 1832) -- valid -- angular unicorn
  Acanthochitona Gray, 1821 -- valid
  Acanthochitona andersoni Watters, 1981 -- invalid -- smooth glass-hair chiton
  Acanthochitona angelica Dall, 1919 -- valid
  Acanthochitona avicula (Carpenter, 1864) -- valid
  Acanthochitona balesae Abbott, 1954 -- valid -- slender glass-hair chiton
  Acanthochitona hemphilli (Pilsbry, 1893) -- valid -- red glass-hair chiton
  Acanthochitona imperatrix Watters, 1981 -- valid
  Acanthochitona pygmaea (Pilsbry, 1893) -- valid -- striate glass-hair chiton
  Acanthochitona roseojugum Lyons, 1988 -- valid
  Acanthochitona zebra Lyons, 1988 -- valid
  Acanthochitonida -- invalid
  Acanthochitonidae Pilsbry, 1893 -- valid
  Acanthodoris Gray, 1850 -- valid
  Acanthodoris armata O'Donoghue, 1927 -- valid
  Acanthodoris atrogriseata O'Donoghue, 1927 -- valid
  Acanthodoris brunnea MacFarland, 1905 -- valid -- brown spiny doris
  Acanthodoris caerulescens Bergh, 1880 -- valid
  Acanthodoris hudsoni MacFarland, 1905 -- valid
  Acanthodoris lutea MacFarland, 1925 -- valid -- orange-peel doris
  Acanthodoris nanaimoensis O'Donoghue, 1921 -- valid -- wine-plumed spiny doris
  Acanthodoris pilosa (Abildgaard, 1789) -- valid -- hairy spiny doris
  Acanthodoris rhodoceras Cockerell, 1905 -- valid -- black-tipped spiny doris
  Acanthopleura Guilding, 1829 -- valid
  Acanthopleura granulata (Gmelin, 1791) -- valid -- West Indian fuzzy chiton
  Acanthotrophon Hertlein and Strong, 1951 -- valid
  Acanthotrophon striatoides Vokes, 1980 -- valid -- knobbed trophon
  Acar Gray, 1857 -- valid
  Acar bailyi Bartsch, 1931 -- valid -- miniature ark
  Acella Haldeman, 1841 -- valid
  Acella haldemani (W. G. Binney, 1867) -- valid -- spindle lymnaea
  Acesta excavata (Fabricius, 1779) -- invalid
  Acila H. Adams and A. Adams, 1858 -- valid
  Acila castrensis (Hinds, 1843) -- valid -- divaricate nutclam
  Acirsa Morch, 1857 -- valid
  Acirsa borealis (Lyell, 1841) -- valid -- chalky wentletrap
  Acirsa costulata Mighels and Adams, 1842 -- invalid
  Aclididae G. O. Sars, 1878 -- valid
  Aclis Loven, 1846 -- valid
  Aclis carolinensis Bartsch, 1911 -- valid -- Carolina aclis
  Aclis eolis Bartsch, 1947 -- valid
  Aclis fernamdinae Dall, 1927 -- invalid
  Aclis hendersoni Dall, 1927 -- valid -- angular aclis
  Aclis hypergonia Scwengel and Mcginty, 1942 -- invalid -- angular aclis
  Aclis occidentalis (Hemphill, 1894) -- valid -- Pacific aclis
  Aclis shepardiana Dall, 1919 -- valid
  Aclis tanneri (Bartsch, 1947) -- invalid
  Aclis tenuis A. E. Verrill, 1882 -- valid -- thin aclis
  Aclis turrita (Carpenter, 1864) -- valid -- turreted aclis
  Aclis underwoodae (Bartsch, 1947) -- invalid
  Aclis walleri Jeffreys, 1867 -- valid
  Aclistothyra McGinty, 1955 -- valid
  Aclistothyra atlantica McGinty, 1955 -- valid -- Atlantic galeommatid
  Acmaea Eschscholtz, 1833 -- valid
  Acmaea mitra Eschscholtz, 1833 -- valid -- whitecap limpet
  Acmaeidae Carpenter, 1857 -- invalid
  Acochlidioidea -- invalid
  Acroloxidae Thiele, 1931 -- valid -- capshells
  Acroloxus Beck, 1837 -- valid
  Acroloxus coloradensis (J. Henderson, 1930) -- valid -- Rocky Mountain capshell
  Acteocina Gray, 1847 -- valid
  Acteocina atrata P. S. Mikkelsen and P. M. Mikkelsen, 1984 -- valid -- blackback barrel-bubble
  Acteocina bidentata (d'Orbigny, 1841) -- valid -- two-tooth barrel-bubble
  Acteocina bullata (Kiener, 1834) -- valid -- striate barrel-bubble
  Acteocina canaliculata (Say, 1826) -- valid -- channeled barrel-bubble
  Acteocina candei (d'Orbigny, 1841) -- valid
  Acteocina carinata (Carpenter, 1856) -- valid -- keeled barrel-bubble
  Acteocina cerealis (Gould, 1853) -- valid -- grain barrel-bubble
  Acteocina culcitella (Gould, 1853) -- valid -- pillow barrel-bubble
  Acteocina eximia (Baird, 1863) -- valid -- intermediate barrel-bubble
  Acteocina harpa (Dall, 1871) -- valid -- harp baby-bubble
  Acteocina inculta (Gould, 1855) -- valid -- rude barrel-bubble
  Acteocina lepta Woodring, 1928 -- valid
  Acteocina magdalensis (Dall, 1919) -- valid -- Magdalena barrel-bubble
  Acteocina oldroydi Dall, 1925 -- valid
  Acteocina oryza (Totten, 1835) -- valid -- rice barrel-bubble
  Acteocina recta (d'Orbigny, 1841) -- valid -- straight barrel-bubble
  Acteocina smirna Dall, 1919 -- valid
  Acteon Montfort, 1810 -- valid
  Acteon candens Rehder, 1939 -- valid
  Acteon traskii Stearns, 1898 -- valid
  Acteonidae d'Orbigny, 1843 -- valid
  Actinocyclidae O'Donoghue, 1929 -- valid
  Actinonaias Crosse & Fischer, 1894 -- valid
  Actinonaias ligamentina (Lamarck, 1819) -- invalid -- mucket
  Actinonaias pectorosa (Conrad, 1834) -- invalid -- pheasantshell
  Adalaria Bergh, 1879 -- valid
  Adalaria jannae Millen, 1987 -- valid
  Adalaria proxima (Alder and Hancock, 1854) -- valid -- false doris, yellow false doris
  Adalaria tschuktschica Krause, 1885 -- valid
  Addisonia Dall, 1882 -- valid
  Addisonia brophyi J. H. McLean, 1985 -- valid
  Addisonia excentrica (Tiberi, 1857) -- valid
  Addisoniidae Dall, 1882 -- valid
  Admete Moller, 1842 -- valid
  Admete californica (Dall, 1908) -- valid -- California admete
  Admete circumcincta (Dall, 1873) -- invalid -- corded admete
  Admete gracilior (Carpenter, 1869) -- valid -- slender admete
  Admete laevior Leche, 1878 -- valid
  Admete modesta (Carpenter, 1864) -- invalid -- modest admete
  Admete regina Dall, 1911 -- valid -- noble admete
  Admete rhyssa Dall, 1919 -- invalid -- wrinkled admete
  Admete seftoni S. S. Berry, 1956 -- invalid -- stubby admete
  Admete unalashkensis (Dall, 1873) -- invalid -- Aleutian admete
  Admete viridula (Fabricius, 1780) -- valid -- northern admete
  Admete woodworthi Dall, 1905 -- invalid -- graceful admete
  Adontorhina Berry, 1947 -- valid
  Adontorhina cyclia S. S. Berry, 1947 -- valid -- circle axinopsid
  Adontorhina sphaericosa Scott, 1986 -- valid -- inflated axinopsid
  Adula H. Adams and A. Adams, 1857 -- valid
  Adula californiensis (Philippi, 1847) -- valid -- California datemussel
  Adula diegensis (Dall, 1911) -- valid -- San Diego datemussel
  Adula gruneri (Philippi, 1851) -- valid -- curved datemussel
  Adula schmidtii (Schrenck, 1867) -- valid -- Schmidt datemussel
  Aegires Lovén, 1844 -- valid
  Aegires albopunctatus MacFarland, 1905 -- valid -- salt-and-pepper doris
  Aegires sublaevis Odhner, 1932 -- valid
  Aeolidia Cuvier, 1797 -- valid
  Aeolidia papillosa (Linnaeus, 1761) -- valid -- shag-rug aeolis
  Aeolidiella Bergh, 1867 -- valid
  Aeolidiella chromosoma (Cockerell, 1905) -- valid -- frosted spurilla
  Aeolidiella indica Bergh, 1888 -- valid -- vermillion Japanese aeolis
  Aeolidiella olivae MacFarland, 1966 -- valid -- red-tentacle spurilla
  Aeolidiidae Orbigny, 1834 -- invalid
  Aequipecten P. Fischer, 1886 -- valid
  Aequipecten acanthodes (Dall, 1925) -- invalid -- thistle scallop
  Aequipecten exasperatus Sowerby, 1842 -- invalid
  Aequipecten glyptus (A. E. Verrill, 1882) -- valid -- red-ribbed scallop
  Aequipecten muscosus (W. Wood, 1828) -- invalid -- rough scallop
  Aesopus Gould, 1860 -- valid
  Aesopus chrysalloideus (Carpenter, 1864) -- valid -- cocoon dovesnail
  Aesopus eurytoideus (Carpenter, 1864) -- valid
  Aesopus myrmecoon Dall, 1916 -- valid -- ant-egg dovesnail
  Aesopus sanctus Dall, 1919 -- valid -- Santa Monica dovesnail
  Aesopus stearnsii (Tryon, 1883) -- valid
  Aesopus subturritus (Carpenter, 1864) -- valid -- graceful dovesnail
  Aforia Dall, 1889 -- valid
  Aforia circinata (Dall, 1873) -- valid -- keeled aforia
  Agathotoma Cossmann, 1889 -- valid
  Agathotoma candidissima (C. B. Adams, 1845) -- valid
  Agathotoma densestriata (C. B. Adams, 1850) -- valid
  Agathotoma stellata (Morch, 1860) -- valid
  Agatrix R. Petit, 1967 -- valid
  Agatrix agassizii (Dall, 1889) -- valid -- Agassiz's nutmeg
  Aglaja Renier, 1804 -- valid
  Aglaja ocelligera (Bergh, 1893) -- valid -- eyespot aglaja
  Aglajidae Pilsbry, 1895 -- valid
  Agriopoma Dall, 1902 -- valid
  Agriopoma texasianum (Dall, 1892) -- valid -- texas venus
  Akera O. F. Müller, 1776 -- valid
  Akera thompsoni Olsson and McGinty, 1951 -- valid
  Akeridae Pilsbry, 1893 -- invalid
  Akiodoris Bergh, 1879 -- valid
  Akiodoris lutescens Bergh, 1880 -- valid
  Alaba H. Adams and A. Adams, 1853 -- valid
  Alaba incerta (d'Orbigny, 1842) -- valid -- varicose cerith
  Alaba jeanettae Bartsch, 1910 -- valid
  Alasmidonta Say, 1818 -- valid
  Alasmidonta arcula (Lea, 1838) -- valid -- Altamaha arcmussel
  Alasmidonta atropurpurea (Rafinesque, 1831) -- valid -- Cumberland elktoe
  Alasmidonta heterodon (Lea, 1829) -- invalid -- dwarf wedge mussel, dwarf wedgemussel
  Alasmidonta marginata Say, 1818 -- valid -- elktoe
  Alasmidonta mccordi Athearn, 1964 -- valid -- Coosa elktoe
  Alasmidonta raveneliana (Lea, 1834) -- valid -- Appalachian elktoe
  Alasmidonta robusta Clarke, 1981 -- valid -- Carolina elktoe
  Alasmidonta triangulata (Lea, 1858) -- valid -- southern elktoe
  Alasmidonta undulata (Say, 1817) -- valid -- triangle floater
  Alasmidonta varicosa (Lamarck, 1819) -- valid -- brook floater
  Alasmidonta viridis (Rafinesque, 1820) -- invalid -- slippershell mussel
  Alasmidonta wrightiana (Walker, 1901) -- valid -- Ochlockonee arcmussel
  Alcadia Gray, 1840 -- valid
  Alcadia striata (Lamarck, 1822) -- valid -- striate drop
  Alderia Allman, 1845 -- valid
  Alderia modesta (Loven, 1844) -- valid -- modest alderia
  Aldisa Bergh, 1878 -- valid
  Aldisa albomarginata Millen, 1984 -- valid
  Aldisa cooperi Robilliard and Baba, 1972 -- valid
  Aldisa sanguinea (J. G. Cooper, 1863) -- valid -- blood-spot doris
  Aldisa tara Millen, 1984 -- valid
  Aldisa zetlandica (Alder and Hancock, 1854) -- valid
  Aldisidae Odhner, 1939 -- invalid
  Alexania Strand, 1928 -- valid
  Alexania floridana (Pilsbry, 1945) -- valid -- smooth wentletrap
  Alia H. Adams and A. Adams, 1853 -- valid
  Alia carinata (Hinds, 1844) -- valid -- carinate dovesnail
  Alia tuberosa (Carpenter, 1864) -- valid -- variegate dovesnail
  Aligena I. Lea, 1843 -- valid
  Aligena elevata (Stimpson, 1851) -- valid -- eastern aligena
  Aligena texasiana Harry, 1969 -- valid -- Texas aligena
  Allogona Pilsbry, 1939 -- valid
  Allogona lombardii A. G. Smith, 1943 -- valid -- Selway forestsnail
  Allogona profunda (Say, 1821) -- valid -- broad-banded forestsnail
  Allogona ptychophora (A. D. Brown, 1870) -- valid -- Idaho forestsnail
  Allogona townsendiana (I. Lea, 1838) -- valid -- Oregon forestsnail
  Allopeas H. B. Baker, 1935 -- valid
  Allopeas clavulinum (Potiez and Michaud, 1838) -- valid -- spike awlsnail
  Allopeas gracile (Hutton, 1834) -- valid -- graceful awlsnail
  Allopeas mauritianum (Pfeiffer, 1852) -- valid -- Mauritian awlsnail
  Alvania Risso, 1826 -- valid
  Alvania areolata Stimpson, 1851 -- valid
  Alvania auberiana (d'Orbigny, 1842) -- valid -- West Indian alvania, West Indian alvania
  Alvania castanea Moller, 1842 -- invalid
  Alvania compacta (Carpenter, 1864) -- valid
  Alvania latior (Mighels and C. B. Adams, 1842) -- valid
  Alvania microglypta Haas, 1943 -- valid -- fine-cut alvania
  Alvania moerchi (Collins, 1886) -- valid
  Alvania oldroydae Bartsch, 1911 -- valid
  Alvania precipitata (Dall, 1889) -- valid
  Alvania pseudoareolata Waren, 1974 -- valid
  Alvania rosana Bartsch, 1911 -- valid -- Santa Rosa alvania
  Alvania trachisma Bartsch, 1911 -- valid
  Alvania tumida Carpenter, 1857 -- valid
  Amaea H. Adams and A. Adams, 1854 -- valid
  Amaea mitchelli (Dall, 1896) -- valid
  Amaea retifera (Dall, 1889) -- valid -- reticulate wentletrap
  Amathinidae Ponder, 1987 -- valid
  Amauropsis Mörch, 1857 -- valid
  Amauropsis islandica (Gmelin, 1791) -- valid -- Iceland moonsnail
  Amblema Rafinesque, 1820 -- valid
  Amblema elliottii (Lea, 1856) -- valid -- Coosa fiveridge
  Amblema neislerii (Lea, 1858) -- valid -- fat three-ridge, fat threeridge
  Amblema plicata (Say, 1817) -- valid -- threeridge, three-ridge
  Amblema plicata perplicata (Conrad, 1841) -- invalid -- roundlake
  Amblema plicata plicata (Say, 1817) -- invalid -- three-ridge
  Americardia Stewart, 1930 -- valid
  Americardia biangulata (Broderip and G. B. Sowerby I, 1829) -- valid -- western strawberry cockle, western strawberry-cockle
  Americardia guppyi (Thiele, 1910) -- valid -- guppy strawberry cockle, Guppy strawberry-cockle
  Americardia media (Linnaeus, 1758) -- valid -- atlantic strawberry cockle, Atlantic strawberry-cockle
  Americhiton Watters, 1990 -- valid
  Americhiton andersoni (Watters, 1981) -- valid -- smooth glass-hair chiton
  Amiantis Carpenter, 1884 -- valid
  Amiantis callosa (Conrad, 1837) -- valid -- white venus
  Amicula Gray, 1847 -- valid
  Amicula amiculata (Pallas, 1787) -- valid
  Amicula pallasii (Middendorff, 1847) -- valid
  Amicula vestita (Broderip and G. B. Sowerby I, 1829) -- valid
  Ammonitella J. G. Cooper, 1868 -- valid
  Ammonitella yatesii (J. G. Cooper, 1968) -- valid -- tight coin
  Amnicola Gould and Haldeman, 1840 -- valid
  Amnicola clarki Pilsbry, 1917 -- invalid
  Amnicola cora Hubricht, 1979 -- valid -- Foushee Cavesnail
  Amnicola dalli (Pilsbry and Beecher, 1892) -- valid -- Peninsula Amnicola
  Amnicola decisus Haldeman, 1845 -- valid
  Amnicola limosus (Say, 1817) -- valid -- Mud Amnicola
  Amnicola rhombostoma F. G. Thompson, 1968 -- valid -- Squaremouth Amnicola
  Amnicola stygius Hubricht, 1971 -- valid -- Stygian Amnicola
  Amphigyra Pilsbry, 1906 -- valid
  Amphigyra alabamensis Pilsbry, 1906 -- valid -- Shoal Sprite
  Amphissa H. Adams and A. Adams, 1853 -- valid
  Amphissa acutecostata (Philippi, 1844) -- valid
  Amphissa bicolor Dall, 1892 -- valid -- two-tone amphissa
  Amphissa columbiana Dall, 1916 -- valid -- wrinkled amphissa
  Amphissa cymata Dall, 1916 -- valid -- wavy amphissa
  Amphissa reticulata Dall, 1916 -- valid -- reticulate amphissa
  Amphissa undata (Carpenter, 1864) -- valid
  Amphissa versicolor Dall, 1871 -- valid -- variegate amphissa
  Amphithalamus Carpenter, 1864 -- valid
  Amphithalamus inclusus Carpenter, 1864 -- valid
  Amphithalamus vallei Aguayo and Jaume, 1947 -- valid
  Ampullariidae Gray, 1824 -- valid
  Amusium Roding, 1798 -- valid
  Amusium papyraceum (Gabb, 1873) -- valid -- paper scallop
  Amygdalum Megerle von Muhlfeld, 1811 -- valid
  Amygdalum papyrium (Conrad, 1846) -- valid -- Atlantic papermussel
  Amygdalum politum (A. E. Verrill and S. Smith, 1880) -- valid -- polished papermussel
  Amygdalum sagittatum Rehder, 1934 -- valid -- arrow papermussel
  Anadara Gray, 1847 -- valid
  Anadara baughmani Hertlein, 1951 -- valid -- baughman ark, skewed ark
  Anadara brasiliana (Lamarck, 1819) -- valid -- incongruous ark
  Anadara chemnitzii (Philippi, 1851) -- valid -- chemnitz ark, triangular ark
  Anadara floridana (Conrad, 1869) -- valid -- cut-ribbed ark
  Anadara multicostata (G. B. Sowerby I, 1833) -- valid -- many-ribbed ark
  Anadara notabilis (Roding, 1798) -- valid -- eared ark
  Anadara ovalis (Bruguiere, 1789) -- valid -- blood ark
  Anadara transversa (Say, 1822) -- valid -- transverse ark
  Anadara tuberculosa (G. B. Sowerby I, 1833) -- valid -- pustulose ark
  Anadenulus Cockerell, 1890 -- valid
  Anadenulus cockerelli (Hemphill, 1890) -- valid -- American keeled slug
  Anaspidea -- invalid
  Anatina Schumacher, 1817 -- valid
  Anatina anatina (Spengler, 1802) -- valid -- smooth duckclam
  Anatoma Fleming, 1828 -- valid
  Anatoma baxteri J. H. McLean, 1984 -- valid
  Anatoma crispata (Fleming, 1828) -- valid -- crispate scissurelle
  Anatoma lyra (S. S. Berry, 1947) -- valid -- lyre scissurelle
  Anatoma obtusata (Golikov and Gulbin, 1977) -- valid
  Ancistrobasis Dall, 1889 -- valid
  Ancistrobasis depressa (Dall, 1889) -- valid -- depressed basilissa
  Ancistrolepis Dall, 1894 -- valid
  Ancistrolepis beringianus Dall, 1919 -- valid
  Ancistrolepis eucosmius (Dall, 1891) -- valid -- corded whelk
  Ancotrema H. B. Baker, 1931 -- valid
  Ancotrema hybridum (Ancey, 1888) -- valid -- Oregon lancetooth
  Ancotrema sportella (Gould, 1846) -- valid -- beaded lancetooth
  Ancotrema voyanum (Newcomb, 1865) -- valid -- hooded lancetooth
  Ancotrema zopherum Roth, 1990 -- valid -- dusky lancetooth
  Ancula Loven, 1846 -- valid
  Ancula evelinae Er. Marcus, 1961 -- valid
  Ancula gibbosa (Risso, 1818) -- valid -- Atlantic ancula
  Ancula lentiginosa Farmer, 1964 -- valid -- freckled ancula
  Ancula pacifica MacFarland, 1905 -- valid -- Pacific ancula
  Ancylidae Rafinesque, 1815 -- invalid
  Anguispira E. S. Morse, 1864 -- valid
  Anguispira alabama (G. H. Clapp, 1920) -- valid -- alabama disc, Alabama tigersnail
  Anguispira alternata (Say, 1816) -- valid -- flamed disc, flamed tigersnail
  Anguispira cumberlandiana (I. Lea, 1840) -- valid -- cumberland disc, Cumberland tigersnail
  Anguispira fergusoni (Bland, 1861) -- valid -- coastal plains disc, coastal-plain tigersnail
  Anguispira jessica Kutchka, 1938 -- valid -- mountain disc, mountain tigersnail
  Anguispira knoxensis (Pilsbry, 1899) -- valid -- rustic disc, rustic tigersnail
  Anguispira kochi (Pfeiffer, 1821) -- valid -- banded globe, banded tigersnail
  Anguispira macneilli Walker, 1928 -- valid -- Tombigbee tigersnail
  Anguispira mordax (Shuttleworth, 1852) -- valid -- appalachian disc, Appalachian tigersnail
  Anguispira nimapuna H. B. Baker, 1932 -- valid -- nimapuna disc, Nimapu tigersnail
  Anguispira picta (G. H. Clapp, 1920) -- valid -- painted disc, painted snake coiled forest snail, painted tigersnail
  Anguispira rugoderma Hubricht, 1938 -- valid -- pine mountain disc, Pine Mountain tigersnail
  Anguispira strongyloides (Pfeiffer, 1854) -- valid -- southeastern disc, southeastern tigersnail
  Angustipes Colosi, 1922 -- valid
  Angustipes ameghini (Gambetta, 1923) -- valid -- black-velvet leatherleaf
  Anidolyta Willan, 1987 -- valid
  Anidolyta spongotheras (Bertsch, 1980) -- valid
  Anisodonta Deshayes, 1858 -- valid
  Anisodonta carolina Dall, 1900 -- valid -- Carolina sportella
  Anisodoris Bergh, 1898 -- valid
  Anisodoris lentiginosa Millen, 1982 -- valid -- mottled pale sea-lemon
  Anisodoris nobilis (MacFarland, 1905) -- valid -- Pacific sea-lemon
  Anisodoris worki Ev. Marcus and Er. Marcus, 1967 -- valid
  Annulariidae Henderson and Bartsch, 1920 -- valid
  Anodonta Lamarck, 1799 -- valid
  Anodonta beringiana Middendorff, 1851 -- invalid -- Yukon floater
  Anodonta californiensis Lea, 1852 -- valid -- California floater
  Anodonta cataracta Say, 1817 -- invalid
  Anodonta cataracta cataracta Say, 1817 -- invalid -- eastern floater
  Anodonta cataracta fragilis Lamarck, 1819 -- invalid -- Newfoundland floater
  Anodonta cataracta marginata Say, 1817 -- invalid -- Gaspe floater
  Anodonta couperiana Lea, 1840 -- invalid -- barrel floater
  Anodonta dejecta Lewis, 1875 -- invalid -- woebegone floater
  Anodonta heardi Gordon & Hoeh, 1995 -- invalid -- Apalachicola floater
  Anodonta implicata Say, 1829 -- invalid -- alewife floater
  Anodonta kennerlyi Lea, 1860 -- valid -- western floater
  Anodonta nuttalliana Lea, 1838 -- valid -- winged floater
  Anodonta oregonensis Lea, 1838 -- valid -- Oregon floater
  Anodonta suborbiculata Say, 1831 -- invalid -- flat floater
  Anodonta wahlametensis Lea, 1838 -- invalid
  Anodontia Link, 1807 -- valid
  Anodontia alba Link, 1807 -- valid -- buttercup lucine
  Anodontia philippiana (Reeve, 1850) -- valid -- chalky buttercup lucine
  Anodontoides Simpson in F. C. Baker, 1898 -- valid
  Anodontoides ferussacianus (Lea, 1834) -- valid -- cylindrical papershell
  Anodontoides radiatus (Conrad, 1834) -- invalid -- rayed creekshell
  Anomalocardia Schumacher, 1817 -- valid
  Anomalocardia auberiana (d'Orbigny, 1842) -- valid -- pointed venus
  Anomalocardia brasiliana (Gmelin, 1791) -- valid -- Carib pointed-venus
  Anomia Linnaeus, 1758 -- valid
  Anomia peruviana d'Orbigny, 1846 -- valid -- Peruvian jingle
  Anomia simplex D'Orbigny, 1842 -- valid -- common jingle
  Anomia squamula Linnaeus, 1758 -- valid -- prickly jingle
  Anomiidae Rafinesque, 1815 -- valid
  Antalis antillarum (d'Orbigny, 1842) -- valid -- Antillean tuskshell
  Antalis berryi (A. G. Smith and M. Gordon, 1948) -- valid -- berry tuskshell
  Antalis ceratum (Dall, 1881) -- valid -- waxy tuskshell
  Antalis entale (Linnaeus, 1758) -- valid -- occidental tuskshell
  Antalis pilsbryi (Rehder, 1942) -- valid -- pilsbry tuskshell
  Antalis pretiosum (G. B. Sowerby II, 1860) -- valid -- wampum tuskshell
  Antalis taphrium (Dall, 1889) -- valid -- green tuskshell
  Anticlimax Pilsbry and McGinty, 1946 -- valid
  Anticlimax athleenae (Pilsbry and McGinty, 1946) -- valid
  Anticlimax pilsbryi (McGinty, 1945) -- valid -- cupola vitrinella
  Antillophos Woodring, 1928 -- valid
  Antillophos beauii (P. Fischer and Bernardi, 1857) -- valid
  Antillophos candeanus (d'Orbigny, 1842) -- valid -- beaded phos
  Antillophos candei (d'Orbigny, 1848) -- invalid -- beaded phos
  Antiopella barbarensis (J. G. Cooper, 1863) -- invalid -- cockscomb nudibranch
  Antiopella mucloc Er. Marcus, 1958 -- invalid
  Antiplanes Dall, 1902 -- valid
  Antiplanes abarbareus Dall, 1919 -- valid
  Antiplanes briseis Dall, 1919 -- valid
  Antiplanes bulimoides Dall, 1919 -- valid
  Antiplanes catalinae (Raymond, 1904) -- valid
  Antiplanes litus Dall, 1919 -- valid
  Antiplanes motojimai (Habe, 1958) -- valid
  Antiplanes motojimai aquilonalis Kantor and Sysoev, 1991 -- valid
  Antiplanes perversus (Gabb, 1865) -- invalid
  Antiplanes sanctiioannis (E. A. Smith, 1875) -- valid
  Antiplanes thalea (Dall, 1902) -- valid
  Antiplanes vinosus (Dall, 1874) -- valid
  Antrobia Hubricht, 1971 -- valid
  Antrobia culveri Hubricht, 1971 -- valid -- Tumbling Creek Cavesnail
  Antrorbis Hershler and F. G. Thompson, 1990 -- valid
  Antrorbis breweri Hershler and F. G. Thompson, 1990 -- valid -- Conical Siltsnail
  Antroselates Hubricht, 1963 -- valid
  Antroselates spiralis Hubricht, 1963 -- valid -- Shaggy Cavesnail
  Antroselatus Hubricht, 1963 -- invalid
  Aorotrema Schwengel and McGinty, 1942 -- valid
  Aorotrema cistronium (Dall, 1889) -- valid
  Aorotrema pontogenes (Schwengel and McGinty, 1942) -- valid
  Aperiovula Cate, 1973 -- valid
  Aperiovula abbotti Cate, 1973 -- valid
  Aphaostracon F. G. Thompson, 1968 -- valid
  Aphaostracon asthenes F. G. Thompson, 1968 -- valid -- Blue Spring Hydrobe
  Aphaostracon chalarogyrus F. G. Thompson, 1968 -- valid -- Freemouth Hydrobe
  Aphaostracon hypohyalinum F. G. Thompson, 1968 -- valid -- Suwanee Hydrobe
  Aphaostracon monas (Pilsbry, 1899) -- valid -- Wekiwa Hydrobe
  Aphaostracon pachynotum F. G. Thompson, 1968 -- valid -- Thick-shell Hydrobe, Thick-shelled Hydrobe
  Aphaostracon pycnum F. G. Thompson, 1968 -- invalid -- dense hydrobe
  Aphaostracon rhadinum F. G. Thompson, 1968 -- valid -- Slough Hydrobe
  Aphaostracon theiocrenetum F. G. Thompson, 1968 -- valid -- Clifton Spring Hydrobe
  Aphaostracon xynoelictum F. G. Thompson, 1968 -- valid -- Fenney Spring Hydrobe
  Aphelodoris von Ihering, 1886 -- valid
  Aphelodoris antillensis (Bergh, 1879) -- valid
  Aplacophora -- invalid
  Aplexa Fleming, 1820 -- valid
  Aplexa elongata (Say, 1821) -- valid -- Lance Aplexa
  Aplustridae Gray, 1847 -- valid
  Aplysia Linnaeus, 1767 -- valid
  Aplysia brasiliana Rang, 1828 -- valid -- sooty seahare, mottled seahare
  Aplysia californica J. G. Cooper, 1863 -- valid -- California seahare
  Aplysia cervina (Dall and Simpson, 1901) -- valid
  Aplysia dactylomela Rang, 1828 -- valid -- spotted seahare
  Aplysia donca Ev. Marcus and Er. Marcus, 1960 -- valid
  Aplysia geographica (A. Adams and Reeve, 1850) -- valid
  Aplysia juliana Quoy and Gaimard, 1832 -- valid -- walking seahare
  Aplysia morio (A. E. Verrill, 1901) -- valid -- atlantic black seahare, sooty seahare
  Aplysia parvula Morch, 1863 -- valid -- pygmy seahare
  Aplysia reticulopoda Beeman, 1960 -- valid -- net-foot seahare
  Aplysia vaccaria Winkler, 1955 -- valid -- California black seahare
  Aplysia willcoxi Heilprin, 1886 -- invalid
  Aplysiidae Rafinesque, 1815 -- invalid
  Aplysiopsis Deshayes, 1835 -- valid
  Aplysiopsis enteromorphae (Cockerell and Eliot, 1905) -- valid
  Aplysiopsis olivae Mcfarland, 1966 -- valid
  Aplysiopsis zebra K. B. Clark, 1982 -- valid
  Apodopsis Pilsbry and McGinty, 1949 -- invalid
  Apodopsis novimundi Pilsbry and McGinty, 1949 -- invalid
  Apodosis Pilsbry and McGinty, 1949 -- invalid
  Apodosis novimundi Pilsbry and McGinty, 1949 -- invalid
  Aporrhaididae -- invalid
  Aporrhais da Costa, 1778 -- valid
  Aporrhais occidentalis Beck, 1836 -- valid -- American pelicanfoot
  Appalachina Pilsbry, 1940 -- valid
  Appalachina chilhoweensis (J. Lewis, 1870) -- valid -- queen crater
  Appalachina sayana (Pilsbry, 1906) -- valid -- spike-lip crater
  Aquilonaria Dall, 1886 -- valid
  Aquilonaria turneri Dall, 1886 -- valid
  Arca Linnaeus, 1758 -- valid
  Arca imbricata Bruguiere, 1789 -- valid -- mossy ark
  Arca zebra (Swainson, 1833) -- valid -- turkey wing
  Archaeogastropoda Thiele, 1925 -- invalid
  Archaeopulmonata -- invalid
  Archidorididae Bergh, 1891 -- invalid
  Archidoris Bergh, 1878 -- valid
  Archidoris montereyensis (J. G. Cooper, 1863) -- valid -- Monterey sea-lemon
  Archidoris odhneri (MacFarland, 1966) -- valid -- white night doris
  Architaenioglossa -- invalid
  Architectonica Roding, 1798 -- valid
  Architectonica nobilis Roding, 1798 -- valid -- common sundial
  Architectonicidae Gray, 1850 -- valid
  Arcidae Lamarck, 1809 -- valid
  Arcidens Simpson, 1900 -- valid
  Arcidens confragosus (Say, 1829) -- valid -- rock pocketbook
  Arcinella Schumacher, 1817 -- valid
  Arcinella arcinella (Linnaeus, 1767) -- valid -- spiny jewelbox
  Arcinella cornuta Conrad, 1866 -- valid -- Florida spiny jewelbox
  Arcoida Stoliczka, 1871 -- invalid
  Arcopsis Von Koenen, 1885 -- valid
  Arcopsis adamsi (Dall, 1886) -- valid -- adams ark, cancellate ark
  Arcopsis solida (G. B. Sowerby I, 1833) -- valid -- solid ark
  Arctica Schumacher, 1817 -- valid
  Arctica islandica (Linnaeus, 1767) -- valid -- ocean quahog
  Arcticidae Newton, 1891 -- valid
  Arctinula greenlandica (Sowerby, 1842) -- invalid -- Greenland scallop
  Arctomelon Dall, 1915 -- valid
  Arctomelon stearnsii (Dall, 1872) -- valid -- Alaska volute
  Arene H. Adams and A. Adams, 1854 -- valid
  Arene bairdii (Dall, 1889) -- valid -- warty cyclostreme
  Arene briareus (Dall, 1881) -- valid -- briar cyclostreme
  Arene cruentata (Megerle von Muhlfeld, 1829) -- valid -- star cyclostreme
  Arene tricarinata (Stearns, 1872) -- valid -- gem cyclostreme
  Arene variabilis (Dall, 1889) -- valid -- variable cyclostreme
  Arene venustula Aguayo and Rehder, 1936 -- valid -- graceful cyclostreme
  Argonauta argo Linnaeus, 1758 -- valid -- greater argonaut
  Argopecten Monterosato, 1889 -- valid
  Argopecten circularis (Sowerby, 1835) -- invalid
  Argopecten gibbus (Linnaeus, 1758) -- valid -- Atlantic calico scallop
  Argopecten irradians (Lamarck, 1819) -- valid -- bay scallop
  Argopecten irradians amplicostatus (Dall, 1898) -- valid
  Argopecten irradians concentricus (Say, 1822) -- valid
  Argopecten irradians irradians (Lamarck, 1819) -- valid -- bay scallop
  Argopecten lineolaris (Lamarck, 1819) -- valid -- lined scallop
  Argopecten nucleus (Born, 1778) -- valid -- nucleus scallop
  Argopecten ventricosus (G. B. Sowerby II, 1842) -- valid -- Pacific calico scallop
  Ariolimax Morch, 1859 -- valid
  Ariolimax californicus J. G. Cooper, 1872 -- valid -- california banana slug, California bananaslug
  Ariolimax columbianus (Gould, 1851) -- valid -- pacific banana slug, Pacific bananaslug
  Ariolimax dolichophallus Mead, 1943 -- valid -- slender banana slug, slender bananaslug
  Arion Ferussac, 1819 -- valid
  Arion ater (Linnaeus, 1758) -- valid -- black arion
  Arion circumscriptus Johnston, 1828 -- valid -- brown-banded arion
  Arion distinctus Mabille, 1868 -- valid -- darkface arion
  Arion fasciatus (Nilsson, 1823) -- valid -- orange-banded arion
  Arion hortensis Ferussac, 1819 -- valid -- garden arion
  Arion intermedius (Normand, 1852) -- valid -- hedgehog arion
  Arion owenii Davies, 1979 -- valid -- warty arion
  Arion rufus (Linnaeus, 1758) -- valid -- chocolate arion
  Arion silvaticus Lohmander, 1937 -- valid -- forest arion
  Arion subfuscus (Draparnaud, 1805) -- valid -- dusky arion
  Arion sylvaticus Lohmander, 1937 -- invalid -- forest arion
  Arionidae Gray, 1840 -- valid
  Arkansia Ortmann & Walker, 1912 -- invalid
  Arkansia wheeleri Ortmann & Walker, 1912 -- invalid -- Wheeler's pearly mussel, Ouachita rock pocketbook
  Armina Rafinesque, 1814 -- valid
  Armina californica (J. G. Cooper, 1863) -- valid -- California armina
  Armina cordellensis Gosliner and Behrens, 1996 -- valid
  Armina mulleri (von Ihering, 1886) -- valid -- Brazilian armina
  Armina tigrina Rafinesque, 1814 -- valid -- tiger armina
  Armina wattla Ev. Marcus and Er. Marcus, 1967 -- valid
  Arminidae Rafinesque, 1814 -- invalid
  Asaphis Modeer, 1793 -- valid
  Asaphis deflorata (Linnaeus, 1758) -- valid -- gaudy sanguin
  Ascobulla Ev. Marcus, 1972 -- valid
  Ascobulla ulla (Er. Marcus and Ev. Marcus, 1970) -- valid -- rice-grain bubblesnail
  Ashmunella Pilsbry and Cockerell, 1899 -- valid
  Ashmunella amblya Pilsbry, 1940 -- valid -- Pine Springs woodlandsnail
  Ashmunella angulata Pilsbry, 1905 -- valid -- angulate woodlandsnail
  Ashmunella animasensis Vagvolgyi, 1974 -- valid -- Animas Peak woodlandsnail
  Ashmunella ashmuni (Dall, 1897) -- valid -- Jemez woodlandsnail
  Ashmunella auriculata Vagvolgyi, 1974 -- valid -- Boulder Canyon woodlandsnail
  Ashmunella bequaerti Clench and W. B. Miller, 1966 -- valid -- Goat Cave woodlandsnail
  Ashmunella binneyi Pilsbry and Ferriss, 1917 -- valid -- Silver Creek woodlandsnail
  Ashmunella carlsbadensis Pilsbry, 1932 -- valid -- Guadalupe woodlandsnail
  Ashmunella chiricahuana (Dall, 1896) -- valid -- Cave Creek woodlandsnail
  Ashmunella cockerelli Pilsbry and Ferriss, 1917 -- valid -- Black Range woodlandsnail
  Ashmunella danielsi Pilsbry and Ferriss, 1915 -- valid -- Whitewater Creek woodlandsnail
  Ashmunella edithae Pilsbry and Cheatum, 1951 -- valid -- McKittrick woodlandsnail
  Ashmunella esuritor Pilsbry, 1915 -- valid -- barefoot woodlandsnail
  Ashmunella ferrissi Pilsbry, 1905 -- valid -- Reed's Mountain woodlandsnail
  Ashmunella harrisi Metcalf and Smartt, 1977 -- valid -- Goat Mountain woodlandsnail
  Ashmunella hebardi Pilsbry and Vanatta, 1923 -- valid -- Hacheta Grande woodlandsnail
  Ashmunella kochii G. H. Clapp, 1908 -- valid -- san andreas woodlandsnail
  Ashmunella lenticula Gregg, 1953 -- valid -- Horseshoe Canyon woodlandsnail
  Ashmunella lepiderma Pilsbry and Ferriss, 1910 -- valid -- Whitetail woodlandsnail
  Ashmunella levettei (Bland, 1881) -- valid -- Huachuca woodlandsnail
  Ashmunella macromphala Vagvolgyi, 1974 -- valid -- Cook's Peak woodlandsnail
  Ashmunella mearnsii (Dall, 1895) -- valid -- big hatchet woodlandsnail
  Ashmunella mendax Pilsbry and Ferriss, 1917 -- valid -- Iron Creek woodlandsnail
  Ashmunella mogollonensis Pilsbry, 1905 -- valid -- Mogollon woodlandsnail
  Ashmunella mudgei Cheatum, 1971 -- valid -- Sawtooth Mountain woodlandsnail
  Ashmunella organensis Pilsbry, 1936 -- valid -- Organ Mountain woodlandsnail
  Ashmunella pasonis (Drake, 1951) -- valid -- Franklin Mountain woodlandsnail
  Ashmunella pilsbryana Ferriss, 1914 -- valid -- Blue Mountain woodlandsnail
  Ashmunella proxima Pilsbry, 1905 -- valid -- Chiricahua woodlandsnail
  Ashmunella pseudodonta (Dall, 1897) -- valid -- Capitan woodlandsnail
  Ashmunella rhyssa (Dall, 1897) -- valid -- Sierra Blanca woodlandsnail
  Ashmunella rileyensis Metcalf and Hurley, 1971 -- valid -- Mount Riley woodlandsnail
  Ashmunella salinasensis Vagvolgyi, 1974 -- valid -- Salinas Peak woodlandsnail
  Ashmunella sprouli R. W. Fullington and K. E. Fullington, 1978 -- valid -- Hell's Canyon woodlandsnail
  Ashmunella tetrodon Pilsbry and Ferriss, 1915 -- valid -- Dry Creek woodlandsnail
  Ashmunella thomsoniana (Ancey, 1887) -- valid -- sangre de cristo woodlandsnail
  Ashmunella todseni Metcalf and Smartt, 1977 -- valid -- Maple Canyon woodlandsnail
  Ashmunella varicifera Ancey, 1901 -- valid -- Miller Canyon woodlandsnail
  Ashmunella walkeri Ferriss, 1904 -- valid -- Florida Mountain woodlandsnail
  Aspella Morch, 1877 -- valid
  Aspella castor Radwin and D'Attilio, 1976 -- valid
  Aspella senex Dall, 1903 -- valid -- graybeard aspella
  Asperiscala de Boury, 1909 -- valid
  Asperiscala bellastriata (Carpenter, 1864) -- valid -- well-threaded wentletrap
  Asperiscala cookeana (Dall, 1917) -- valid
  Asperiscala lowei (Dall, 1906) -- valid
  Assiminea Fleming, 1828 -- valid
  Assiminea californica (Tryon, 1865) -- valid -- California assiminea
  Assiminea infima S. S. Berry, 1947 -- valid -- Badwater Snail
  Assiminea pecos Taylor, 1987 -- valid -- Pecos Assiminea
  Assiminea succinea (Pfeiffer, 1840) -- valid -- Atlantic assiminea
  Assiminea translucens (Carpenter, 1864) -- valid
  Assimineidae H. Adams and A. Adams, 1856 -- valid
  Astarte J. Sowerby, 1816 -- valid
  Astarte alaskensis Dall, 1903 -- invalid
  Astarte arctica (J. E. Gray, 1824) -- valid -- Arctic astarte
  Astarte borealis (Schumacher, 1817) -- valid -- boreal astarte
  Astarte castanea (Say, 1822) -- valid -- smooth astarte
  Astarte compacta Carpenter, 1864 -- valid -- compact astarte
  Astarte crenata (J. E. Gray, 1824) -- valid -- crenulate astarte
  Astarte elliptica (T. Brown, 1827) -- valid -- elliptical astarte
  Astarte esquimalti (Baird, 1863) -- valid -- eskimo astarte, wavy-line astarte
  Astarte montagui (Dillwyn, 1817) -- valid -- narrow-hinge astarte
  Astarte nana Dall, 1886 -- valid -- dwarf astarte
  Astarte rollandi Bernardi, 1859 -- invalid
  Astarte undata Gould, 1841 -- valid -- wavy astarte
  Astarte vernicosa Dall, 1903 -- valid -- varnished astarte
  Astartidae d'Orbigny, 1844 -- valid
  Asteronotidae Thiele, 1931 -- invalid
  Asterophila Randall and Heath, 1912 -- valid
  Asterophila japonica Randall and Heath, 1912 -- valid
  Asthenothaerus Carpenter, 1864 -- valid
  Asthenothaerus diegensis (Dall, 1915) -- valid -- San Diego thraciid
  Asthenothaerus hemphilli Dall, 1886 -- valid -- hemphill thracid, square thraciid
  Astraea phoebia Röding, 1798 -- invalid
  Astralium Link, 1807 -- valid
  Astralium phoebium (Röding, 1798) -- valid -- longspine starsnail
  Astyris H. Adams and A. Adams, 1853 -- valid
  Astyris amiantis Dall, 1919 -- valid
  Astyris aurantiaca Dall, 1871 -- valid -- golden dovesnail
  Astyris diaphana A. E. Verrill, 1882 -- valid -- translucent dovesnail
  Astyris gausapata (Gould, 1850) -- valid -- shaggy dovesnail
  Astyris hypodra (Dall, 1916) -- valid
  Astyris lunata (Say, 1826) -- valid -- lunar dovesnail
  Astyris multilineata (Dall, 1889) -- valid -- brown-band dovesnail
  Astyris profundi (Dall, 1889) -- valid -- deepwater dovesnail
  Astyris pura A. E. Verrill, 1882 -- valid -- simple dovesnail
  Astyris raveneli (Dall, 1889) -- valid
  Astyris rosacea (Gould, 1839) -- valid -- rosy northern dovesnail
  Atagema Gray, 1850 -- valid
  Atagema alba (O'Donoghue, 1927) -- valid -- hunchback doris
  Atagema prea (Ev. Marcus and Er. Marcus, 1967) -- valid
  Atlanta Lesueur, 1817 -- valid
  Atlanta brunnea J. E. Gray, 1850 -- valid
  Atlanta californiensis Seapy and Richter, 1993 -- valid
  Atlanta helicinoidea J. E. Gray, 1850 -- valid
  Atlanta helicinoides Souleyet, 1852 -- invalid
  Atlanta inclinata J. E. Gray, 1850 -- valid
  Atlanta inflata J. E. Gray, 1850 -- valid
  Atlanta lesueuri Souleyet, 1852 -- invalid
  Atlanta lesueurii J. E. Gray, 1850 -- valid
  Atlanta peronii Lesueur, 1817 -- valid
  Atlanta turriculata D'Orbigny, 1836 -- valid
  Atlantidae Wiegmann and Ruthe, 1832 -- invalid
  Atrina Gray, 1847 -- valid
  Atrina oldroydii Dall, 1901 -- valid -- Oldroyd penshell
  Atrina rigida (Lightfoot, 1786) -- valid -- stiff penshell
  Atrina seminuda (Lamarck, 1819) -- valid -- half-naked penshell
  Atrina serrata (G. B. Sowerby I, 1825) -- valid -- sawtooth penshell
  Atrina texta Hertlein, Hanna and Strong, 1943 -- valid -- woven penshell
  Attiliosa Emerson, 1968 -- valid
  Attiliosa philippiana (Dall, 1889) -- valid
  Atys Montfort, 1810 -- valid
  Atys caribaeus (d'Orbigny, 1841) -- valid -- Caribbean glassy-bubble
  Atys castus Carpenter, 1864 -- valid -- clean glassy-bubble
  Atys nonscriptus (A. Adams, 1850) -- valid -- clean-slate glassy-bubble
  Atys obscuratus Dall, 1896 -- valid -- obscure glassy-bubble
  Atys riiseanus Morch, 1875 -- valid
  Atys sandersoni Dall, 1881 -- valid
  Austraeolis Burn, 1962 -- valid
  Austraeolis catina Ev. Marcus and Er. Marcus, 1967 -- valid
  Austroneaera Powell, 1937 -- valid
  Austroneaera semipellucida (Kuroda, 1948) -- valid -- North Pacific austroneaera
  Austrotrophon Dall, 1902 -- valid
  Austrotrophon catalinensis (I. S. Oldroyd, 1927) -- valid -- Catalina forreria
  Austrotrophon cerrosensis catalinensis (I. S. Oldroyd, 1927) -- invalid -- Catalina forreria
  Axelella Petit, 1988 -- valid
  Axelella smithii (Dall, 1888) -- valid
  Axinodon A. E. Verrill and Bush, 1898 -- valid
  Axinodon redondoensis (T. A. Burch, 1941) -- valid -- elongate axinopsid
  Axinopsida Keen and Chavan, 1951 -- valid
  Axinopsida cordata (A. E. Verrill and Bush, 1898) -- valid -- heart-shaped axinopsid, heart axinopsid
  Axinopsida orbiculata (G. O. Sars, 1878) -- valid -- orbicular axinopsid
  Axinopsida serricata (Carpenter, 1864) -- valid -- silky axinopsid, lenticular axinopsid
  Axinulus A. E. Verrill and Bush, 1898 -- valid
  Axinulus eumyaria (M. Sars, 1870) -- valid -- mya cleftclam
  Babakina Roller, 1972 -- valid
  Babakina festiva (Roller, 1972) -- valid -- single-stalk aeolis
  Babakinidae Roller, 1973 -- valid
  Babelomurex Coen, 1922 -- valid
  Babelomurex dalli (Emerson and D'Attilio, 1963) -- valid
  Babelomurex mansfieldi (McGinty, 1940) -- valid
  Babelomurex oldroydi (I. S. Oldroyd, 1929) -- valid
  Bactrocythara Woodring, 1922 -- valid
  Bactrocythara asarca (Dall and Simpson, 1901) -- valid
  Baeolidia Bergh, 1888 -- valid
  Baeolidia benteva Er. Marcus, 1958 -- valid
  Bailya M. Smith, 1944 -- valid
  Bailya intricata (Dall, 1884) -- valid -- intricate phos
  Bailya parva (C. B. Adams, 1850) -- valid
  Bailya weberi (Watters, 1983) -- valid -- banded phos
  Balconorbis Hershler and Longley, 1986 -- valid
  Balconorbis uvaldensis Hershler and Longley, 1986 -- valid -- Balcones Ghostsnail
  Bankia Gray, 1842 -- valid
  Bankia carinata (J. E. Gray, 1827) -- valid -- carinate shipworm
  Bankia fimbriatula Moll and Roch, 1931 -- valid -- fimbriate shipworm
  Bankia gouldi (Bartsch, 1908) -- valid -- gould shipworm, cupped shipworm
  Bankia setacea (Tryon, 1863) -- valid -- feathery shipworm
  Baptodoris Bergh, 1884 -- valid
  Baptodoris mimetica Gosliner, 1991 -- valid
  Barbatia Gray, 1847 -- valid
  Barbatia bailyi (Bartsch, 1931) -- invalid -- baily miniature ark
  Barbatia cancellaria (Lamarck, 1819) -- valid -- red-brown ark
  Barbatia candida (Helbling, 1779) -- valid -- white-beard ark
  Barbatia domingensis (Lamarck, 1819) -- valid -- white miniature ark
  Barbatia reeveana (d'Orbigny, 1846) -- valid -- low-rib ark
  Barbatia tenera (C. B. Adams, 1845) -- valid -- doc bales ark, delicate ark
  Barleeia Clark, 1853 -- valid
  Barleeia alderi (Carpenter, 1856) -- valid
  Barleeia bentleyi Bartsch, 1920 -- valid
  Barleeia carpenteri Bartsch, 1920 -- valid
  Barleeia haliotiphila Carpenter, 1864 -- valid -- abalone barleysnail
  Barleeia oldroydi Bartsch, 1920 -- valid
  Barleeia subtenuis Carpenter, 1864 -- valid -- fragile barleysnail
  Barleeia tincta Guppy, 1895 -- valid -- Caribbean barleysnail
  Barleeiidae Gray, 1857 -- valid
  Barnea Risso, 1826 -- valid
  Barnea subtruncata (G. B. Sowerby I, 1834) -- valid -- pacific mud piddock, Pacific mud-piddock
  Barnea truncata (Say, 1822) -- valid -- atlantic mud piddock, Atlantic mud-piddock
  Bartschia significans Rehder, 1943 -- invalid
  Basommatophora -- invalid
  Basterotia Hoernes, 1859 -- valid
  Basterotia corbuloidea Dall, 1899 -- valid -- corbula sportella
  Basterotia elliptica (Recluz, 1850) -- valid -- elliptical sportella
  Basterotia quadrata (Hanley, 1843) -- valid -- square sportella
  Bathyarca Kobelt, 1891 -- valid
  Bathyarca anomala (A. E. Verrill and Bush, 1898) -- valid -- anomalous bathyark
  Bathyarca frielei (Friele, 1877) -- valid -- friele bathyark, boreal bathyark
  Bathyarca glacialis (J. E. Gray, 1824) -- valid -- glacial bathyark
  Bathyarca glomerula (Dall, 1881) -- valid -- little-ball bathyark
  Bathyarca pectunculoides (Scacchi, 1833) -- valid -- comb bathyark
  Bathybembix Crosse, 1893 -- valid
  Bathybembix bairdii (Dall, 1889) -- valid
  Bathytoma Harris and Burrows, 1891 -- valid
  Bathytoma viabrunnea (Dall, 1889) -- valid
  Batillaria Benson, 1842 -- valid
  Batillaria attramentaria (G. B. Sowerby II, 1855) -- valid -- Japanese false cerith
  Batillaria minima (Gmelin, 1791) -- valid -- West Indian false cerith
  Batillariidae Thiele, 1929 -- valid
  Bellaspira Conrad, 1868 -- valid
  Bellaspira grippi (Dall, 1908) -- valid
  Bellaspira pentagonalis (Dall, 1889) -- valid -- orange-rib drillia
  Benthomangelia Thiele, 1925 -- valid
  Benthomangelia bandella (Dall, 1881) -- valid
  Benthonella Dall, 1889 -- valid
  Benthonella tenella (Jeffreys, 1869) -- valid
  Benthonellania Dall, 1889 -- valid
  Benthonellania acuticostata (Dall, 1889) -- valid
  Benthonellania colombiana (Romer and Moore, 1988) -- valid
  Benthonellania xanthias (Watson, 1886) -- valid -- sharp-rib alvania
  Beringius Dall, 1886 -- valid
  Beringius behringi (Middendorff, 1848) -- valid
  Beringius beringii (Middendorff, 1848) -- invalid
  Beringius crebricostatus (Dall, 1877) -- valid -- thick-cord whelk
  Beringius eyerdami A. G. Smith, 1959 -- valid
  Beringius frielei Dall, 1895 -- invalid
  Beringius indentatus Dall, 1919 -- valid
  Beringius kennicottii (Dall, 1871) -- valid
  Beringius malleatus (Dall, 1884) -- invalid -- hammered whelk
  Beringius marshalli (Dall, 1919) -- invalid
  Beringius stimpsoni (Gould, 1860) -- valid
  Beringius turtoni (Bean, 1834) -- valid
  Beringius undatus Dall, 1919 -- valid
  Bernardina Dall, 1910 -- valid
  Bernardina bakeri Dall, 1910 -- valid -- baker bernard-clam, Baker bernardclam
  Bernardinidae Keen, 1969 -- invalid
  Berryteuthis magister (Berry, 1913) -- valid -- magister armhook squid
  Berthelinia Gardiner, 1936 -- valid
  Berthelinia caribbea Edmunds, 1963 -- valid -- Caribbean bivalved snail
  Berthella de Blainville, 1825 -- valid
  Berthella agassizii (MacFarland, 1909) -- valid
  Berthella californica (Dall, 1900) -- valid -- California sidegill slug
  Berthella stellata (Risso, 1826) -- valid
  Berthella strongi (MacFarland, 1966) -- valid
  Berthellina Gardiner, 1936 -- valid
  Berthellina engeli (Gardiner, 1936) -- valid
  Binneya J. G. Cooper, 1863 -- valid
  Binneya notabilis J. G. Cooper, 1863 -- valid -- santa barbara shelled slug, Santa Barbara shelledslug
  Biomphalaria Preston, 1910 -- valid
  Biomphalaria glabrata (Say, 1818) -- valid -- bloodfluke planorb
  Biomphalaria havanensis (Pfeiffer, 1839) -- valid -- Ghost Ramshorn
  Birgella F. C. Baker, 1926 -- valid
  Birgella subglobosus (Say, 1825) -- valid -- Globe Siltsnail
  Bithynia Leach, 1818 -- valid
  Bithynia tentaculata (Linnaeus, 1758) -- valid -- mud bithynia
  Bithyniidae Gray, 1857 -- valid
  Bittiolum Cossmann, 1906 -- valid
  Bittiolum alternatum (Say, 1822) -- valid
  Bittiolum fastigiatum (Carpenter, 1864) -- valid
  Bittiolum varium (Pfeiffer, 1840) -- valid -- grass cerith
  Bittium Gray, 1847 -- valid
  Bittium rugatum (Carpenter, 1864) -- invalid
  Bittium vancouverense Dall and Bartsch, 1910 -- valid
  Bivalvia Linnaeus, 1758 -- valid -- bivalves, clams, bivalves, palourdes, bivalve, mexilhão, ostra
  Blauneria Shuttleworth, 1854 -- valid
  Blauneria heteroclita (Montagu, 1808) -- valid -- left-handed melampus, left-hand melampus
  Boonea Robertson, 1978 -- valid
  Boonea bisuturalis (Say, 1822) -- valid -- two-groove odostome
  Boonea cincta (Carpenter, 1864) -- valid
  Boonea impressa (Say, 1822) -- valid -- impressed odostome
  Boonea seminuda (C. B. Adams, 1839) -- valid -- half-smooth odostome
  Boreacola Bernard, 1979 -- valid
  Boreacola dawsoni (Jeffreys, 1864) -- valid -- hook-hinge montacutid
  Boreocingula Golikov and Kussakin, 1974 -- valid
  Boreocingula castanea (Moller, 1842) -- valid
  Boreocingula globulus (Moller, 1842) -- valid
  Boreocingula martyni (Dall, 1887) -- valid
  Boreotrophon Fischer, 1884 -- valid
  Boreotrophon alaskanus Dall, 1902 -- valid
  Boreotrophon avalonensis Dall, 1902 -- valid -- Avalon trophon
  Boreotrophon bentleyi Dall, 1908 -- valid
  Boreotrophon beringi Dall, 1902 -- invalid -- tabulate trophon
  Boreotrophon clathratus (Linnaeus, 1767) -- valid -- clathrate trophon
  Boreotrophon coronatus (H. Adams and A. Adams, 1864) -- valid -- crown trophon
  Boreotrophon cymatus Dall, 1902 -- invalid -- wavy trophon
  Boreotrophon disparilis (Dall, 1891) -- valid -- girdled trophon
  Boreotrophon eucymatus Dall, 1902 -- valid -- grooved trophon
  Boreotrophon kabati J. H. McLean, 1996 -- valid
  Boreotrophon keepi (Strong and Hertlein, 1937) -- valid
  Boreotrophon multicostatus (Eschscholtz, 1829) -- valid -- ribbed trophon
  Boreotrophon muriciformis (Dall, 1877) -- invalid
  Boreotrophon orpheus (Gould, 1849) -- valid -- threaded trophon
  Boreotrophon pacificus Dall, 1902 -- invalid -- elegant trophon
  Boreotrophon pedroanus (Arnold, 1903) -- valid
  Boreotrophon raymondi (Moody, 1916) -- valid
  Boreotrophon stuarti (E. A. Smith, 1880) -- valid -- winged trophon
  Boreotrophon triangulatus (Carpenter, 1864) -- valid -- triangular trophon
  Boreotrophon tripherus Dall, 1902 -- valid -- rotund trophon
  Boreotrophon truncatus (Strom, 1768) -- valid -- bobtail trophon
  Bornia Philippi, 1836 -- valid
  Bornia longipes (Stimpson, 1855) -- valid -- borniaclam
  Borsonella Dall, 1918 -- valid
  Borsonella bartschi (Arnold, 1903) -- valid
  Borsonella coronadoi (Dall, 1908) -- valid
  Borsonella diegensis (Dall, 1908) -- valid
  Borsonella hooveri (Arnold, 1903) -- valid
  Borsonella merriami (Arnold, 1903) -- valid
  Borsonella omphale Dall, 1919 -- valid
  Borsonella pinosensis Bartsch, 1944 -- valid
  Bosellia Trinchese, 1891 -- valid
  Bosellia corinneae Ev. Marcus, 1973 -- valid
  Bosellia marcusi Ev. Marcus, 1972 -- valid
  Bosellia mimetica Trinchese, 1891 -- valid
  Bothriopupa Pilsbry, 1898 -- valid
  Bothriopupa variolosa (Gould, 1848) -- valid -- pitted birddrop
  Botula Mörch, 1853 -- valid
  Botula fusca (Gmelin, 1791) -- valid -- cinnamon mussel
  Brachidontes Swainson, 1840 -- valid
  Brachidontes adamsianus (Dunker, 1857) -- valid -- Adams mussel
  Brachidontes domingensis (Lamarck, 1819) -- valid -- Santo Domingo mussel
  Brachidontes exustus (Linnaeus, 1758) -- valid -- scorched mussel
  Brachidontes modiolus (Linnaeus, 1767) -- valid -- yellow mussel
  Brachycythara Woodring, 1928 -- valid
  Brachycythara barbarae Lyons, 1972 -- valid
  Brachycythara biconica (C. B. Adams, 1850) -- valid
  Bractechlamys Iredale, 1939 -- valid
  Bractechlamys antillarum (Recluz, 1853) -- valid -- Antillean scallop
  Bradybaena Beck, 1837 -- valid
  Bradybaena similaris (Ferussac, 1821) -- valid -- Asian trampsnail
  Bradybaenidae Pilsbry, 1934 -- invalid
  Buccinidae Rafinesque, 1815 -- valid
  Buccinum aleuticum Dall, 1895 -- valid -- Aleut whelk
  Buccinum amaliae Verkruzen, 1878 -- valid
  Buccinum angulosum J. E. Gray, 1839 -- valid -- angular whelk
  Buccinum baerii (Middendorff, 1848) -- valid
  Buccinum bulimuloideum Dall, 1907 -- valid
  Buccinum castaneum Dall, 1877 -- invalid
  Buccinum castaneum castaneum Dall, 1877 -- invalid -- chestnut whelk
  Buccinum castaneum fluctuatum Dall, 1919 -- invalid
  Buccinum castaneum triplostephanum Dall, 1919 -- invalid
  Buccinum chishimanum Pilsbry, 1904 -- valid
  Buccinum ciliatum Fabricius, 1780 -- valid
  Buccinum cnismatopleura Dall, 1919 -- invalid
  Buccinum cyaneum Bruguiere, 1792 -- valid -- bluish whelk
  Buccinum cyaneum cyaneum Bruguiere, 1792 -- valid -- bluish whelk
  Buccinum cyaneum patulum G. O. Sars, 1878 -- valid -- bluish whelk
  Buccinum cyaneum perdix Morch, 1868 -- valid -- bluish whelk
  Buccinum eugrammatum Dall, 1907 -- valid -- lirate whelk
  Buccinum fischerianum Dall, 1871 -- invalid
  Buccinum fringillum Dall, 1877 -- valid -- finch whelk
  Buccinum glaciale Linnaeus, 1761 -- valid -- glacial whelk
  Buccinum gouldii A. E. Verrill, 1882 -- valid
  Buccinum hertzensteini Verkruzen, 1882 -- valid
  Buccinum hydrophanum Hancock, 1846 -- valid
  Buccinum inexhaustum Verkruzen, 1878 -- valid
  Buccinum kadiakense Dall, 1907 -- valid -- kodiak whelk
  Buccinum micropoma Thorson, 1944 -- valid -- berry whelk
  Buccinum moerchi Friele, 1877 -- valid
  Buccinum nivale Friele, 1882 -- valid
  Buccinum ochotense (Middendorff, 1848) -- valid -- Okhotsk whelk
  Buccinum onismatopleura Dall, 1919 -- invalid
  Buccinum pemphigus Dall, 1907 -- valid
  Buccinum percrassum Dall, 1883 -- valid -- crude whelk
  Buccinum physematum Dall, 1919 -- valid
  Buccinum picturatum Dall, 1877 -- valid -- painted whelk
  Buccinum planeticum Dall, 1919 -- valid -- wandering whelk
  Buccinum plectrum Stimpson, 1865 -- valid -- sinuous whelk
  Buccinum polare J. E. Gray, 1839 -- invalid
  Buccinum polaris J. E. Gray, 1839 -- valid -- polar whelk
  Buccinum scalariforme Moller, 1842 -- valid -- ladder whelk
  Buccinum sericatum Hancock, 1846 -- valid -- silky whelk
  Buccinum sigmatopleura Dall, 1907 -- valid
  Buccinum simulatum Dall, 1907 -- valid
  Buccinum solenum Dall, 1919 -- valid
  Buccinum striatissimum G. B. Sowerby III, 1899 -- valid
  Buccinum strigillatum Dall, 1891 -- valid
  Buccinum strigillatum fucanum Dall, 1907 -- valid -- juanmore whelk
  Buccinum tenellum Dall, 1883 -- valid
  Buccinum totteni Stimpson, 1865 -- valid -- thin whelk
  Buccinum undatum Linnaeus, 1758 -- valid -- waved whelk
  Bufonaria Schumacher, 1817 -- valid
  Bufonaria bufo (Bruguiere, 1792) -- valid -- chestnut frogsnail
  Bulbus Brown, 1839 -- valid
  Bulbus fragilis (Leach, 1819) -- valid -- fragile moonsnail
  Bulimnaea Haldeman, 1841 -- valid
  Bulimnaea megasoma (Say, 1824) -- valid -- mammoth lymnaea
  Bulimulidae Tryon, 1867 -- valid
  Bulimulus Leach, 1814 -- valid
  Bulimulus guadalupensis (Bruguiere, 1789) -- valid -- West Indian bulimulus
  Bulla Linnaeus, 1758 -- valid
  Bulla clausa Dall, 1889 -- valid -- imperforate bubble
  Bulla gemma (A. E. Verrill, 1880) -- valid -- jewel bubble
  Bulla gouldiana Pilsbry, 1895 -- valid -- California bubble
  Bulla solida Gmelin, 1791 -- valid -- solid bubble
  Bulla striata Bruguiere, 1792 -- valid -- striate bubble
  Bullidae Rafinesque, 1815 -- invalid
  Bullina Férussac, 1822 -- valid
  Bullina exquisita McGinty, 1955 -- valid -- exquisite bubble
  Bullinidae Gray, 1850 -- invalid
  Bursa Roding, 1798 -- valid
  Bursa corrugata Perry, 1811 -- valid -- gaudy frogsnail
  Bursa corrugata ponderosa (Reeve, 1844) -- valid -- gaudy frogsnail
  Bursa granularis Roding, 1798 -- valid -- Cuba frogsnail
  Bursa granularis cubaniana (d'Orbigny, 1842) -- valid -- Cuba frogsnail
  Bursa grayana Dunker, 1862 -- valid -- elegant frogsnail
  Bursa ranelloides (Reeve, 1844) -- valid -- fine-sculpted frogsnail
  Bursa ranelloides tenuisculpta (Dautzenberg and H. Fischer, 1906) -- valid -- fine-sculpted frogsnail
  Bursa rhodostoma (G. B. Sowerby I or II, 1835) -- valid -- St. Thomas frogsnail
  Bursa rhodostoma thomae (d'Orbigny, 1842) -- valid -- St. Thomas frogsnail
  Bursatella de Blainville, 1817 -- valid
  Bursatella leachii de Blainville, 1817 -- valid -- ragged seahare
  Bursatella leachii pleii Rang, 1828 -- valid -- ragged seahare
  Bursidae Thiele, 1925 -- valid
  Bushia Dall, 1886 -- valid
  Bushia elegans (Dall, 1886) -- valid -- elegant bushclam
  Busycon candelabrum (Lamarck, 1816) -- valid -- splendid whelk
  Busycon carica (Gmelin, 1791) -- valid -- knobbed whelk
  Busycon laeostomum Kent, 1982 -- valid -- snow whelk
  Busycon lyonsi Petuch, 1987 -- valid
  Busycon pulleyi Hollister, 1958 -- valid -- prickly whelk
  Busycon sinistrum Hollister, 1958 -- valid -- lightning whelk
  Busycotypus canaliculatus (Linnaeus, 1758) -- valid -- channeled whelk
  Busycotypus plagosus (Conrad, 1862) -- valid -- shouldered pearwhelk
  Busycotypus spiratus (Lamarck, 1816) -- valid -- pearwhelk
  Cadlina Bergh, 1878 -- valid
  Cadlina flavomaculata MacFarland, 1905 -- valid -- yellow-spot cadlina
  Cadlina laevis (Linnaeus, 1767) -- valid -- white Atlantic cadlina
  Cadlina limbaughorum Lance, 1962 -- valid
  Cadlina luteomarginata MacFarland, 1966 -- valid -- yellow-edge cadlina
  Cadlina modesta MacFarland, 1966 -- valid -- modest cadlina
  Cadlina pacifica Bergh, 1879 -- valid
  Cadlina rumia Er. Marcus, 1955 -- valid
  Cadlina scabriuscula (Bergh, 1890) -- valid
  Cadlina sparsa (Odhner, 1921) -- valid -- dark-spot cadlina
  Caducifer weberi Watters, 1983 -- invalid -- banded phos
  Cadulus aberrans Whiteaves, 1887 -- valid -- aberrant toothshell
  Cadulus transitorius (J. B. Henderson, 1920) -- valid -- inflated toothshell
  Caecidae Gray, 1850 -- valid
  Caecum Fleming, 1813 -- valid
  Caecum antillarum Carpenter, 1858 -- valid -- Antillean caecum
  Caecum bipartitum de Folin, 1870 -- valid
  Caecum breve de Folin, 1867 -- valid
  Caecum californicum Dall, 1885 -- valid -- California caecum
  Caecum carolinianum Dall, 1892 -- valid -- Carolina caecum
  Caecum carpenteri (Bartsch, 1920) -- valid
  Caecum clava de Folin, 1867 -- valid -- club caecum
  Caecum condylum Moore, 1969 -- valid -- bone caecum
  Caecum cooperi S. Smith, 1860 -- valid
  Caecum cornucopiae (Carpenter, 1858) -- valid -- horn-of-plenty caecum
  Caecum crebricinctum Carpenter, 1864 -- valid -- many-named caecum
  Caecum cubitatum (de Folin, 1868) -- valid -- smooth caecum
  Caecum cycloferum de Folin, 1867 -- valid -- fatlip caecum
  Caecum dalli Bartsch, 1920 -- valid
  Caecum floridanum Stimpson, 1851 -- valid -- Florida caecum
  Caecum gurgulio Carpenter, 1858 -- valid -- windpipe caecum
  Caecum heladum Olsson and Harbison, 1953 -- valid -- fine-line caecum
  Caecum imbricatum Carpenter, 1858 -- valid -- imbricate caecum
  Caecum insularum Moore, 1969 -- valid
  Caecum johnsoni Winkley, 1908 -- valid
  Caecum nitidum Stimpson, 1851 -- valid -- little horn caecum
  Caecum occidentale (Bartsch, 1920) -- valid -- western caecum
  Caecum orcutti (Dall, 1885) -- valid
  Caecum plicatum Carpenter, 1858 -- valid -- plicate caecum
  Caecum pulchellum Stimpson, 1851 -- valid -- beautiful caecum
  Caecum regulare Carpenter, 1858 -- valid
  Caecum ryssotitum de Folin, 1867 -- valid -- minute caecum
  Caecum strigosum de Folin, 1868 -- valid
  Caecum subvolutum de Folin, 1874 -- valid
  Caecum textile de Folin, 1867 -- valid -- textile caecum
  Caecum tortile Dall, 1892 -- valid -- twisted caecum
  Caecum vestitum de Folin, 1868 -- valid -- Vera Cruz caecum
  Caelatura Conrad, 1853 -- valid
  Caelatura rustica (Watson, 1886) -- valid
  Cahuillus Roth, 1996 -- valid
  Cahuillus greggi (W. B. Miller, 1981) -- valid -- Panamint desertsnail
  Cahuillus indioensis (Yates, 1890) -- valid -- Coachella desertsnail
  Calinaticina J. Q. Burch and Campbell, 1963 -- valid
  Caliphylla A. Costa, 1867 -- valid
  Caliphylla mediterranea (A. Costa, 1867) -- valid
  Caliphyllidae Tiberi, 1881 -- invalid
  Calliodentaliidae Chistikov, 1975 -- valid
  Calliodentalium callipeplum (Dall, 1889) -- valid -- gorgeous tuskshell
  Calliostoma Swainson, 1840 -- valid
  Calliostoma adelae Schwengel, 1951 -- valid -- Keys topsnail
  Calliostoma annulatum (Lightfoot, 1786) -- valid -- purple-ring topsnail
  Calliostoma bairdii A. E. Verrill and S. Smith, 1880 -- valid
  Calliostoma bairdii bairdii A. E. Verrill and S. Smith, 1880 -- valid
  Calliostoma bairdii hendersoni Dall, 1927 -- valid
  Calliostoma bairdii oregon Clench and Turner, 1960 -- valid
  Calliostoma bairdii psyche Dall, 1927 -- valid
  Calliostoma bairdii rosewateri Clench and Turner, 1960 -- valid
  Calliostoma barbouri Clench and Aguayo, 1946 -- valid
  Calliostoma bernardi J. H. McLean, 1984 -- valid
  Calliostoma canaliculatum (Lightfoot, 1786) -- valid -- channeled topsnail
  Calliostoma dentatum Quinn, 1992 -- valid -- sprocket topsnail
  Calliostoma euglyptum (A. Adams, 1855) -- valid -- sculptured topsnail
  Calliostoma fascinans Schwengel and McGinty, 1942 -- valid -- enchanting topsnail
  Calliostoma gemmulatum Carpenter, 1864 -- valid -- gem topsnail
  Calliostoma gloriosum Dall, 1871 -- valid -- glorious topsnail
  Calliostoma hendersoni Dall, 1927 -- valid
  Calliostoma javanicum (Lamarck, 1822) -- valid -- chocolate-line topsnail
  Calliostoma jujubinum (Gmelin, 1791) -- valid -- mottled topsnail
  Calliostoma keenae J. H. McLean, 1970 -- valid
  Calliostoma ligatum (Gould, 1849) -- valid -- blue topsnail
  Calliostoma marionae Dall, 1906 -- valid -- mahogany topsnail
  Calliostoma occidentale (Mighels and C. B. Adams, 1842) -- valid -- boreal topsnail
  Calliostoma platinum Dall, 1890 -- valid -- silvery topsnail
  Calliostoma psyche Dall, 1889 -- valid -- psyche topsnail
  Calliostoma pulchrum (C. B. Adams, 1850) -- valid -- beautiful topsnail
  Calliostoma roseolum Dall, 1881 -- valid -- rosy topsnail
  Calliostoma sapidum Dall, 1881 -- valid -- ratchet topsnail
  Calliostoma sayanum Dall, 1889 -- valid
  Calliostoma scalenum Quinn, 1992 -- valid -- Gulf Stream topsnail
  Calliostoma splendens Carpenter, 1864 -- valid -- splendid topsnail
  Calliostoma supragranosum Carpenter, 1864 -- valid -- granulose topsnail
  Calliostoma tampaense (Conrad, 1846) -- valid -- Tampa Bay topsnail
  Calliostoma tricolor Gabb, 1865 -- valid -- tricolor topsnail
  Calliostoma turbinum Dall, 1896 -- valid -- spindle topsnail
  Calliostoma variegatum Carpenter, 1864 -- valid -- variegate topsnail
  Calliostoma yucatecanum Dall, 1881 -- valid -- depressed topsnail
  Calliostomatidae Thiele, 1924 -- valid
  Calliotropis Seguenza, 1903 -- valid
  Calliotropis regalis (A. E. Verrill and S. Smith, 1880) -- valid -- regal spiny margarite
  Callista Poli, 1791 -- valid
  Callista eucymata (Dall, 1890) -- valid -- glory-of-the-seas venus
  Callistochiton Dall, 1879 -- valid
  Callistochiton asthenes (S. S. Berry, 1919) -- valid
  Callistochiton decoratus Keep, 1887 -- valid
  Callistochiton palmulatus Dall, 1879 -- valid
  Callistochiton portobelensis Ferreira, 1976 -- valid -- Portobelo chiton
  Callistochiton shuttleworthianus Pilsbry, 1893 -- valid -- eastern orange chiton
  Callistoplacidae Pilsbry, 1893 -- invalid
  Calotrophon Hertlien and Strong, 1951 -- valid
  Calotrophon andrewsi Vokes, 1976 -- valid
  Calotrophon ostrearum (Conrad, 1846) -- valid -- mauve-mouth drill
  Calycidoris Abraham, 1876 -- valid
  Calycidoris guentheri Abraham, 1876 -- valid
  Calyptoconcha Bouchet and Warén, 1993 -- valid
  Calyptoconcha pellucida (A. E. Verrill, 1880) -- valid -- transluscent lamellaria
  Calyptraea Lamarck, 1799 -- valid
  Calyptraea burchi A. G. Smith and M. Gordon, 1948 -- valid
  Calyptraea centralis (Conrad, 1841) -- valid -- circular chinese hat, circular Chinese-hat
  Calyptraea fastigiata Gould, 1846 -- valid -- pacific chinese hat, Pacific Chinese-hat
  Calyptraeidae Blainville, 1824 -- invalid
  Camaenidae Pilsbry, 1895 -- valid
  Campeloma Rafinesque, 1819 -- valid
  Campeloma brevispirum F. C. Baker, 1928 -- valid
  Campeloma crassulum Rafinesque, 1819 -- valid -- Ponderous Campeloma
  Campeloma decampi (W. G. Binney, 1865) -- valid -- Slender Campeloma
  Campeloma decisum (Say, 1817) -- valid -- Pointed Campeloma
  Campeloma exile (Anthony, 1860) -- invalid
  Campeloma floridense Call, 1886 -- valid -- Purple-throat Campeloma, Purple-throated Campeloma
  Campeloma geniculum (Conrad, 1834) -- valid -- Ovate Campeloma
  Campeloma gibbum (Currier, 1867) -- invalid
  Campeloma leptum Mattox, 1940 -- invalid
  Campeloma lewisi Walker, 1915 -- invalid
  Campeloma limum (Anthony, 1860) -- valid -- File Campeloma
  Campeloma milesi (Lea, 1863) -- valid
  Campeloma parthenum Vail, 1979 -- valid -- Maiden Campeloma
  Campeloma regulare (Lea, 1841) -- valid -- Cylinder Campeloma
  Campeloma rufum (Haldeman, 1841) -- valid
  Campeloma tannum Mattox, 1940 -- invalid
  Cancellaria Lamarck, 1799 -- valid
  Cancellaria adelae Pilsbry, 1940 -- valid
  Cancellaria cooperii Gabb, 1865 -- valid
  Cancellaria corbicula Dall, 1908 -- invalid -- basket nutmeg
  Cancellaria crawfordiana Dall, 1891 -- valid
  Cancellaria middendorffiana (Dall, 1884) -- invalid
  Cancellaria reticulata (Linnaeus, 1767) -- valid
  Cancellaria reticulata adelae Pilsbry, 1940 -- invalid
  Cancellaria richardpetiti Petuch, 1987 -- valid
  Cancellariidae Forbes and Hanley, 1851 -- valid
  Candidula Kobelt, 1871 -- valid
  Candidula intersecta (Poiret, 1801) -- valid -- wrinkled helicellid
  Cantharus Roding, 1798 -- valid
  Cantharus cancellarius (Conrad, 1846) -- valid -- cancellate cantharus
  Cantharus multangulus (Philippi, 1848) -- valid -- ribbed cantharus
  Capulidae Fleming, 1822 -- valid
  Capulus Montfort, 1810 -- valid
  Capulus californicus Dall, 1900 -- valid -- California capsnail
  Capulus incurvus (Gmelin, 1791) -- valid -- incurved capsnail
  Caracolus Montfort, 1810 -- valid
  Caracolus marginella (Gmelin, 1791) -- valid -- banded caracol
  Cardiapoda D'Orbigny, 1835 -- valid
  Cardiapoda placenta (Lesson, 1830) -- valid -- flat cardiapod
  Cardiidae Lamarck, 1809 -- valid
  Cardiomya A. Adams, 1864 -- valid
  Cardiomya balboae (Dall, 1916) -- valid -- Balboa cardiomya
  Cardiomya behringensis (Leche, 1883) -- valid -- Bering cardiomya
  Cardiomya costellata (Deshayes, 1830) -- valid -- little-ribbed cardiomya
  Cardiomya gemma A. E. Verrill and Bush, 1898 -- valid -- precious cardiomya
  Cardiomya glypta (Bush, 1885) -- valid -- carved cardiomya
  Cardiomya ornatissima (d'Orbigny, 1842) -- valid -- ornate cardiomya
  Cardiomya pectinata (Carpenter, 1864) -- valid -- pectinate cardiomya
  Cardiomya perrostrata (Dall, 1881) -- valid -- rostrate cardiomya
  Cardiomya planetica (Dall, 1908) -- valid -- planet cardiomya, fine-rib cardiomya
  Cardiomya striata (Jeffreys, 1876) -- valid -- striate cardiomya
  Carditamera Conrad, 1838 -- valid
  Carditamera floridana Conrad, 1838 -- valid -- broad-ribbed carditid
  Carditidae Férussac, 1822 -- valid
  Carditopsis E. A. Smith, 1881 -- valid
  Carditopsis smithii (Dall, 1896) -- valid -- tiny condylclam
  Careliopsis Morch, 1875 -- valid
  Careliopsis styliformis (Morch, 1875) -- valid
  Caribachlamys Waller, 1993 -- valid
  Caribachlamys imbricata (Gmelin, 1791) -- valid -- knobby scallop
  Caribachlamys mildredae (Bayer, 1941) -- valid -- alternate-ribbed scallop
  Caribachlamys ornata (Lamarck, 1819) -- valid -- ornate scallop
  Caribachlamys sentis (Reeve, 1853) -- valid -- scaly scallop
  Carinaria Lamarck, 1801 -- valid
  Carinaria cithara Benson, 1835 -- valid -- harp carinaria
  Carinaria cristata (Linnaeus, 1767) -- valid
  Carinaria galea Benson, 1835 -- valid -- helmet carinaria
  Carinaria lamarcki Peron and Lesueur, 1810 -- valid
  Carinoturris Bartsch, 1944 -- valid
  Carinoturris fortis Bartsch, 1944 -- valid
  Carychiidae Jeffreys, 1830 -- invalid
  Carychium O. F. Müller, 1773 -- valid
  Carychium clappi Hubricht, 1959 -- valid -- Appalachian thorn
  Carychium exiguum (Say, 1822) -- valid -- obese thorn
  Carychium exile Lea, 1842 -- valid -- ice thorn
  Carychium mexicanum Pilsbry, 1891 -- valid -- southern thorn
  Carychium minimum Muller, 1774 -- valid -- tiny herald snail, herald thorn
  Carychium nannodes G. H. Clapp, 1905 -- valid -- file thorn
  Carychium occidentale Pilsbry, 1891 -- valid -- western thorn
  Carychium riparium Hubricht, 1978 -- valid -- floodplain thorn
  Carychium stygium Call, 1897 -- valid -- cave thorn
  Carychium tridentatum (Risso, 1826) -- valid -- dentate thorn
  Caryocorbula Bruguiere, 1792 -- valid
  Caryocorbula porcella (Dall, 1916) -- valid -- ribbed corbula
  Casmaria H. Adams and A. Adams, 1853 -- valid
  Casmaria ponderosa (Gmelin, 1791) -- valid -- Atlantic casmaria
  Casmaria ponderosa atlantica Clench, 1944 -- valid -- Atlantic casmaria
  Cassidae Latreille, 1825 -- valid
  Cassis Scopoli, 1777 -- valid
  Cassis flammea (Linnaeus, 1758) -- valid -- flame helmet
  Cassis madagascariensis Lamarck, 1822 -- valid -- cameo helmet
  Cassis tuberosa (Linnaeus, 1758) -- valid -- Caribbean helmet
  Catinella Pease, 1870 -- valid
  Catinella aprica Hubricht, 1968 -- valid -- diurnal ambersnail
  Catinella gabbii (Tryon, 1866) -- valid -- riblet ambersnail
  Catinella hubrichti Grimm, 1960 -- valid -- Snowhill ambersnail
  Catinella oklahomarum (Webb, 1953) -- valid -- detritis ambersnail, detritus ambersnail
  Catinella parallela Franzen, 1979 -- valid
  Catinella pinicola Grimm, 1960 -- valid -- pinewoods ambersnail
  Catinella protracta Franzen, 1983 -- valid
  Catinella pugilator Hubricht, 1961 -- valid -- weedpatch ambersnail
  Catinella rehderi (Pilsbry, 1948) -- valid -- chrome ambersnail
  Catinella stretchiana (Bland, 1865) -- valid -- Sierra ambersnail
  Catinella texana Hubricht, 1961 -- valid
  Catinella vagans (Pilsbry, 1900) -- valid -- mudbank ambersnail
  Catinella vermeta (Say, 1829) -- valid -- suboval ambersnail
  Catinella waccamawensis Franzen, 1981 -- valid
  Catinella wandae (Webb, 1953) -- valid -- slope ambersnail
  Catriona Winckworth, 1941 -- valid
  Catriona columbiana (O'Donoghue, 1922) -- valid -- red-tentacle cuthona
  Catriona gymnota (Couthouy, 1838) -- valid -- orange-tip cuthona
  Catriona maua Ev. Marcus and Er. Marcus, 1960 -- valid
  Catriona oba Ev. Marcus, 1970 -- valid
  Catriona rickettsi Behrens, 1984 -- valid
  Cavolinia Abildgaard, 1791 -- valid
  Cavolinia gibbosa (d'Orbigny, 1836) -- valid -- gibbose cavoline
  Cavolinia inflexa (Lesueur, 1813) -- valid -- inflexed cavoline
  Cavolinia tridentata (Niebuhr, 1775) -- valid -- three-tooth cavoline
  Cavolinia uncinata (Rang, 1829) -- valid -- uncinate cavoline
  Cavoliniidae H. Adams and A. Adams, 1854 -- invalid
  Cecilioides Férussac, 1814 -- valid
  Cecilioides acicula (Muller, 1774) -- valid -- blind awlsnail
  Cecilioides aperta (Swainson, 1840) -- valid -- obtuse awlsnail
  Cecina A. Adams, 1861 -- valid
  Cecina manchurica A. Adams, 1861 -- valid
  Cenchritis von Martens, 1900 -- valid
  Cenchritis muricatus (Linnaeus, 1758) -- valid -- beaded periwinkle
  Cepaea Held, 1837 -- valid
  Cepaea hortensis (Muller, 1774) -- valid -- white-lip gardensnail
  Cepaea nemoralis (Linnaeus, 1758) -- valid -- grovesnail
  Cephalaspidea P. Fischer, 1883 -- valid
  Cerastoderma Poli, 1795 -- valid
  Cerastoderma elegantulum Beck, 1842 -- valid -- elegant dwarf cockle
  Cerastoderma pinnulatum (Conrad, 1831) -- valid -- northern dwarf cockle
  Ceratophyllidia Elliot, 1903 -- valid
  Ceratophyllidia papilligera (Bergh, 1890) -- valid
  Ceratostoma Herrmannsen, 1846 -- valid
  Ceratostoma foliatum (Gmelin, 1791) -- valid -- foliate thornmouth
  Ceratostoma nuttalli (Conrad, 1837) -- valid
  Ceratozona Dall, 1882 -- valid
  Ceratozona squalida (C. B. Adams, 1845) -- valid -- eastern surf chiton
  Cerberilla Bergh, 1873 -- valid
  Cerberilla mosslandica McDonald and Nybakken, 1975 -- valid -- brown burrowing aeolis
  Cerberilla tanna Ev. Marcus and Er. Marcus, 1960 -- valid
  Ceriidae -- invalid
  Cerion Röding, 1798 -- valid
  Cerion casablancae Bartsch, 1920 -- valid
  Cerion chrysalis (Ferussac in Beck, 1837) -- valid
  Cerion chrysalis fastigatum Maynard, 1896 -- valid
  Cerion incanum (A. Binney, 1851) -- valid -- gray peanut-snail, gray cerion
  Cerion sculptum (Poey, 1858) -- valid
  Cerion sculptum marielinum Torre, 1927 -- valid
  Cerion tridentatum Pilsbry and Vanatta, 1895 -- valid
  Cerion viaregis Bartsch, 1920 -- valid
  Cerithidea Swainson, 1840 -- valid
  Cerithidea californica (Haldeman, 1840) -- valid -- California hornsnail
  Cerithidea costata (E. M. da Costa, 1778) -- valid -- costate hornsnail
  Cerithidea fuscata Gould, 1857 -- valid
  Cerithidea pliculosa (Menke, 1829) -- valid -- plicate hornsnail
  Cerithidea scalariformis (Say, 1825) -- valid -- ladder hornsnail
  Cerithiidae J. Fleming, 1822 -- valid
  Cerithiopsida Bartsch, 1911 -- valid
  Cerithiopsida diegensis (Bartsch, 1911) -- valid
  Cerithiopsida rowelli (Bartsch, 1911) -- valid
  Cerithiopsidae H. Adams and A. Adams, 1853 -- valid
  Cerithiopsidella Bartsch, 1911 -- valid
  Cerithiopsidella alcima (Bartsch, 1911) -- valid
  Cerithiopsidella antefilosa (Bartsch, 1911) -- valid
  Cerithiopsidella cosmia (Bartsch, 1907) -- valid
  Cerithiopsina Bartsch, 1911 -- valid
  Cerithiopsina signa (Bartsch, 1921) -- valid
  Cerithiopsis Forbes and Hanley, 1851 -- valid
  Cerithiopsis albovittata (C. B. Adams, 1850) -- valid
  Cerithiopsis antemunda Bartsch, 1911 -- valid
  Cerithiopsis arnoldi Bartsch, 1911 -- valid
  Cerithiopsis berryi Bartsch, 1911 -- valid
  Cerithiopsis carpenteri Bartsch, 1911 -- valid
  Cerithiopsis cesta Bartsch, 1911 -- valid
  Cerithiopsis charlottensis Bartsch, 1917 -- valid
  Cerithiopsis columna Carpenter, 1864 -- valid
  Cerithiopsis diomedeae Bartsch, 1911 -- valid
  Cerithiopsis emersonii (C. B. Adams, 1839) -- valid
  Cerithiopsis flava (C. B. Adams, 1850) -- valid
  Cerithiopsis fusiformis (C. B. Adams, 1850) -- valid
  Cerithiopsis gloriosa Bartsch, 1911 -- valid
  Cerithiopsis greenii (C. B. Adams, 1839) -- valid
  Cerithiopsis grippi Bartsch, 1917 -- valid
  Cerithiopsis ingens (Bartsch, 1907) -- valid
  Cerithiopsis io Dall and Bartsch, 1911 -- valid
  Cerithiopsis iota (C. B. Adams, 1845) -- valid
  Cerithiopsis jeffreysi Watson, 1885 -- valid
  Cerithiopsis lata (C. B. Adams, 1850) -- valid
  Cerithiopsis montereyensis Bartsch, 1911 -- valid
  Cerithiopsis onealensis Bartsch, 1921 -- valid
  Cerithiopsis paramoea Bartsch, 1911 -- valid
  Cerithiopsis pedroana Bartsch, 1907 -- valid
  Cerithiopsis stejnegeri Dall, 1884 -- valid
  Cerithiopsis stephensae Bartsch, 1909 -- valid
  Cerithiopsis tubercularis Montagu, 1803 -- valid
  Cerithiopsis tubercularis floridana Dall, 1892 -- valid
  Cerithiopsis tumida (Bartsch, 1907) -- valid
  Cerithiopsis vanhyningi Bartsch, 1918 -- valid
  Cerithiopsis virginica J. B. Henderson and Bartsch, 1914 -- valid
  Cerithiopsis willetti Bartsch, 1921 -- invalid
  Cerithium Bruguiere, 1789 -- valid
  Cerithium atratum (Born, 1778) -- valid -- dark cerith
  Cerithium eburneum Bruguiere, 1792 -- valid -- ivory cerith
  Cerithium guinaicum Philippi, 1849 -- valid -- Guinea cerith
  Cerithium lindae Petuch, 1987 -- valid
  Cerithium litteratum (Born, 1778) -- valid -- stocky cerith
  Cerithium lutosum Menke, 1828 -- valid -- variable cerith
  Cerithium muscarum Say, 1822 -- valid -- flyspeck cerith
  Cernuella Schluter, 1838 -- valid
  Cernuella virgata (Muller, 1774) -- valid -- maritime gardensnail
  Cerodrillia Bartsch and Rehder, 1939 -- valid
  Cerodrillia bealiana Schwengel and McGinty, 1942 -- valid
  Cerodrillia clappi Bartsch and Rehder, 1939 -- valid
  Cerodrillia girardi Lyons, 1972 -- valid
  Cerodrillia perryae Bartsch and Rehder, 1939 -- valid
  Cerodrillia schroederi Bartsch and Rehder, 1939 -- invalid
  Cerodrillia simpsoni Dall, 1887 -- invalid
  Cerodrillia thea (Dall, 1884) -- valid -- tea drillia
  Cerodrillia verrillii (Dall, 1881) -- valid
  Chaceia Turner, 1855 -- valid
  Chaceia ovoidea (Gould, 1851) -- valid -- wartneck piddock
  Chaenaxis Pilsbry and Ferriss, 1906 -- valid
  Chaenaxis tuba (Pilsbry and Ferriss, 1906) -- valid -- hollow tuba
  Chaetoderma Loven, 1844 -- valid
  Chaetoderma argenteum Heath, 1911 -- valid -- glistenworm
  Chaetoderma canadense Nierstrasz, 1902 -- valid -- glistenworm
  Chaetoderma elegans Scheltema, 1997 -- valid -- glistenworm
  Chaetoderma hancocki (Schwabl, 1963) -- valid -- glistenworm
  Chaetoderma marinelli (Schwabl, 1963) -- valid -- glistenworm
  Chaetoderma nanulum Heath, 1911 -- valid -- glistenworm
  Chaetoderma nitidulum Loven, 1844 -- valid -- glistenworm
  Chaetoderma productum Wiren, 1892 -- valid -- glistenworm
  Chaetoderma scabrum Heath, 1911 -- valid -- glistenworm
  Chaetodermatidae Ihering, 1876 -- valid
  Chaetodermomorpha -- invalid
  Chaetopleura Shuttleworth, 1853 -- valid
  Chaetopleura apiculata (Say, 1834) -- valid -- eastern beaded chiton
  Chaetopleura gemma Dall, 1879 -- valid
  Chaetopleura janeirensis (J. E. Gray, 1828) -- valid -- West Indian ribbed chiton
  Chaetopleura lanuginosa (Dall, 1879) -- valid
  Chaetopleura staphylophera Lyons, 1985 -- valid
  Chaetopleuridae Plate, 1899 -- invalid
  Chama Linnaeus, 1758 -- valid
  Chama arcana Bernard, 1976 -- valid -- secret jewelbox
  Chama congregata Conrad, 1833 -- valid -- corrugate jewelbox
  Chama florida Lamarck, 1819 -- valid -- pretty jewelbox
  Chama lactuca Dall, 1886 -- valid -- milky jewelbox
  Chama macerophylla Gmelin, 1791 -- valid -- leafy jewelbox
  Chama sarda Reeve, 1847 -- valid -- cherry jewelbox
  Chama sinuosa Broderip, 1835 -- valid -- smooth-edge jewelbox
  Chamaearionta Berry, 1930 -- valid
  Chamaearionta aquaealbae (S. S. Berry, 1922) -- valid -- Whitewater desertsnail
  Chamidae Lamarck, 1809 -- valid
  Charonia Gistel, 1848 -- valid
  Charonia tritonis (Linnaeus, 1758) -- valid -- Atlantic trumpet triton
  Charonia tritonis variegata (Lamarck, 1816) -- valid -- Atlantic trumpet triton
  Charopidae Hutton, 1884 -- valid
  Cheilea Modeer, 1793 -- valid
  Cheilea equestris (Linnaeus, 1758) -- valid -- false cup-and-saucer
  Chelidonura A. Adams, 1850 -- valid
  Chelidonura hirundinina (Quoy and Gaimard, 1833) -- valid -- leech aglaja, swallowtail aglaja
  Chelidonura sabina Er. Marcus and Ev. Marcus, 1970 -- valid -- Sabine Island aglaja
  Chicoreus Montfort, 1810 -- valid
  Chicoreus beauii (P. Fischer and Bernardi, 1857) -- valid
  Chicoreus cailleti (Petit de la Saussaye, 1856) -- valid
  Chicoreus consuela (A. H. Verrill, 1950) -- valid
  Chicoreus dilectus (A. Adams, 1855) -- valid -- lace murex
  Chicoreus florifer dilectus (A. Adams, 1855) -- invalid -- lace murex
  Chicoreus formosus (Sowerby, 1841) -- valid
  Chicoreus mergus Vokes, 1974 -- valid
  Chicoreus oculatus (Reeve, 1845) -- valid
  Chicoreus pomum (Gmelin, 1791) -- valid -- apple murex
  Chione Megerle von Mühlfeld, 1811 -- valid
  Chione californiensis (Broderip, 1835) -- valid -- California venus
  Chione cancellata (Linnaeus, 1767) -- valid -- cross-barred venus
  Chione clenchi Pulley, 1952 -- invalid -- Clench venus
  Chione fluctifraga (G. B. Sowerby II, 1853) -- invalid -- smooth venus
  Chione grus (Holmes, 1858) -- invalid -- gray pygmy venus
  Chione intapurpurea (Conrad, 1849) -- invalid -- lady-in-waiting venus
  Chione latilirata (Conrad, 1841) -- invalid -- imperial venus
  Chione puber (Bory Saint-vincent, 1927) -- invalid -- downy venus
  Chione pygmaea (Lamarck, 1818) -- invalid -- pygmy venus
  Chione undatella (G. B. Sowerby I, 1835) -- valid -- frilled venus
  Chionista Keen, 1958 -- valid
  Chionista fluctifraga (G. B. Sowerby II, 1853) -- valid -- smooth venus
  Chiton Linnaeus, 1758 -- valid
  Chiton tuberculatus Linnaeus, 1758 -- valid -- West Indian green chiton
  Chiton viridis Spengler, 1797 -- valid
  Chitonidae Rafinesque, 1815 -- valid
  Chlamydoconcha Dall, 1884 -- valid
  Chlamydoconcha orcutti Dall, 1884 -- valid -- Orcutt nakedclam
  Chlamys Röding, 1798 -- valid
  Chlamys albida (R. Arnold, 1906) -- valid -- white scallop
  Chlamys behringiana (Middendorff, 1849) -- valid -- Bering scallop
  Chlamys hastata (G. B. Sowerby II, 1842) -- valid -- spear scallop, spiny scallop
  Chlamys imbricata (Gmelin, 1791) -- invalid -- knobby scallop
  Chlamys islandica (Müller, 1776) -- valid -- Iceland scallop
  Chlamys mildredae (Bayer, 1941) -- invalid -- Mildred scallop
  Chlamys multisquamata (Dunker, 1864) -- invalid -- many-ribbed scallop
  Chlamys ornata (Lamarck, 1819) -- invalid -- ornate scallop
  Chlamys rubida (Hinds, 1845) -- valid -- reddish scallop
  Chlamys sentis (Reeve, 1853) -- invalid -- scaly scallop
  Chondropoma L. Pfeiffer, 1847 -- valid
  Chondropoma dentatum (Say, 1825) -- valid -- crenulate horn
  Choristodon Jonas, 1844 -- valid
  Choristodon robustum (G. B. Sowerby I, 1834) -- valid -- Atlantic petricolid
  Chromodorididae Bergh, 1891 -- valid
  Chromodoris Alder and Hancock, 1855 -- valid
  Chromodoris aila Er. Marcus, 1961 -- valid
  Chromodoris binza Ev. Marcus and Er. Marcus, 1963 -- valid
  Chromodoris clenchi (Russell, 1935) -- valid -- harlequin blue doris
  Chromodoris kempfi Ev. Marcus, 1970 -- valid
  Chromodoris macfarlandi Cockerell, 1901 -- valid -- three-stripe doris
  Chromodoris morchii Bergh, 1879 -- valid
  Chromodoris nyalya Ev. Marcus and Er. Marcus, 1967 -- valid -- red-line blue doris
  Chromodoris punctilucens Bergh, 1890 -- valid
  Chrysallida Carpenter, 1857 -- valid
  Chrysallida cancellata (d'Orbigny, 1842) -- valid
  Chrysallida gemmulosa (C. B. Adams, 1850) -- valid
  Chrysallida toroensis (Olsson and McGinty, 1958) -- valid
  Cidarina Dall, 1909 -- valid
  Cidarina cidaris (A. Adams, 1864) -- valid
  Cincinnatia Pilsbry, 1891 -- valid
  Cincinnatia comalensis (Pilsbry and Ferriss, 1906) -- invalid -- Comal Siltsnail
  Cincinnatia floridana (Frauenfeld, 1863) -- invalid -- hyacinth siltsnail
  Cincinnatia fraterna F. G. Thompson, 1968 -- invalid -- creek siltsnail
  Cincinnatia helicogyra F. G. Thompson, 1968 -- invalid -- crystal siltsnail
  Cincinnatia integra (Say, 1821) -- valid -- Midland Siltsnail
  Cincinnatia mica F. G. Thompson, 1968 -- invalid -- Ichetucknee siltsnail
  Cincinnatia monroensis (Dall, 1885) -- invalid -- Enterprise siltsnail
  Cincinnatia parva F. G. Thompson, 1968 -- invalid -- pygmy siltsnail
  Cincinnatia petrifons F. G. Thompson, 1968 -- invalid -- Rock Springs siltsnail
  Cincinnatia ponderosa F. G. Thompson, 1968 -- invalid -- ponderous siltsnail
  Cincinnatia vanhyningi (Vanatta, 1934) -- invalid -- Seminole Siltsnail
  Cincinnatia wekiwae F. G. Thompson, 1968 -- invalid -- Wekiwa Siltsnail
  Cincinnatia winkleyi (Pilsbry, 1912) -- invalid
  Cingula Fleming, 1828 -- valid
  Cingula montereyensis Bartsch, 1912 -- valid
  Cingula robusta scipio Dall, 1887 -- invalid
  Cingula scipio Dall, 1887 -- valid
  Cionella Jeffreys, 1830 -- valid
  Cionella lubrica (Muller, 1774) -- valid -- glossy pillar
  Cionella lubricella (Porro, 1838) -- valid -- thin pillar
  Cionella morseana Doherty, 1878 -- valid -- Appalachian pillar
  Cionella nitens (Gallenstein, 1848) -- valid -- robust pillar
  Cionellidae L. Pfeiffer, 1879 -- invalid
  Cipangopaludina Hannibal, 1912 -- valid
  Cipangopaludina chinensis (Gray, 1834) -- valid -- Chinese mysterysnail
  Cipangopaludina chinensis malleata (Reeve, 1863) -- valid -- Chinese mysterysnail
  Cipangopaludina japonica (von Martens, 1861) -- valid -- Japanese mysterysnail
  Circomphalus Klein, 1853 -- valid
  Circomphalus strigillinus (Dall, 1902) -- valid -- empress venus
  Circulus Jeffreys, 1865 -- valid
  Circulus cosmius Bartsch, 1907 -- valid
  Circulus dalli Bush, 1897 -- valid
  Circulus liratus (Verrill, 1882) -- valid
  Circulus multistriatus (A. E. Verrill, 1884) -- valid -- threaded vitrinella
  Circulus rossellinus Dall, 1919 -- valid
  Circulus semisculptus (Olsson and McGinty, 1958) -- valid
  Circulus texanus (Moore, 1965) -- valid -- Texas vitrinella
  Cirsotrema Morch, 1852 -- valid
  Cirsotrema dalli Rehder, 1945 -- valid
  Cirsotrema pilsbryi (McGinty, 1940) -- valid
  Cittarium Philippi, 1847 -- valid
  Cittarium pica (Linnaeus, 1758) -- valid -- West Indian topsnail
  Clappia Walker, 1909 -- valid
  Clappia cahabensis Clench, 1965 -- valid -- Cahaba pebblesnail, Armored Siltsnail
  Clappia umbilicata (Walker, 1904) -- valid -- umbilicate pebblesnail, Pumpkin Siltsnail
  Clathromangelia di Monterosato, 1884 -- valid
  Clathromangelia fuscoligata (Dall, 1871) -- valid
  Clathromangelia interfossa (Carpenter, 1864) -- valid
  Clathurella Carpenter, 1857 -- valid
  Clathurella canfieldi (Dall, 1871) -- valid
  Clathurella capaniola (Dall, 1919) -- valid
  Clathurella eversoni Tippett, 1995 -- valid
  Clathurella rava (Hinds, 1843) -- valid
  Clathurella rigida (Hinds, 1843) -- valid
  Clinocardium Keen, 1936 -- valid
  Clinocardium blandum (Gould, 1850) -- valid -- smooth cockle, low-rib cockle
  Clinocardium californiense (Deshayes, 1839) -- valid -- california cockle, Aleutian cockle
  Clinocardium ciliatum (Fabricius, 1780) -- valid -- hairy cockle
  Clinocardium fucanum (Dall, 1907) -- invalid -- strait cockle
  Clinocardium nuttallii (Conrad, 1837) -- valid -- Nuttall cockle
  Clinopegma Grant and Gale, 1931 -- valid
  Clinopegma magnum (Dall, 1895) -- valid -- helmet whelk
  Clio Linnaeus, 1767 -- valid
  Clio chaptalii J. E. Gray, 1850 -- valid
  Clio cuspidata (Bosc, 1802) -- valid -- cuspidate clio
  Clio polita (Pelseneer, 1888) -- valid -- two-keel clio
  Clio pyramidata Linnaeus, 1767 -- valid -- pyramid clio
  Clio recurva (Children, 1823) -- valid -- wavy clio
  Clione limacina (Phipps, 1774) -- valid
  Cliopsidae O. G. Costa, 1873 -- valid
  Cliopsis krohnii Troschel, 1854 -- valid
  Cocculina Dall, 1882 -- valid
  Cocculina rathbuni Dall, 1882 -- valid
  Cocculinidae Dall, 1882 -- valid
  Cochlespira Conrad, 1865 -- valid
  Cochlespira elegans (Dall, 1881) -- valid -- elegant star-turris
  Cochlespira radiata (Dall, 1889) -- valid -- lesser star-turris
  Cochlicella Ferussac, 1820 -- valid
  Cochlicella barbara (Linnaeus, 1758) -- valid -- potbellied helicellid
  Cochliolepis Stimpson, 1858 -- valid
  Cochliolepis holmesii (Dall, 1889) -- valid
  Cochliolepis parasitica Stimpson, 1858 -- valid -- parasitic scalesnail
  Cochliolepis striata Dall, 1889 -- valid -- striate scalesnail
  Cochliopa Stimpson, 1865 -- valid
  Cochliopa texana Pilsbry, 1935 -- invalid
  Cochliopina Morrison, 1946 -- valid
  Cochliopina riograndensis (Pilsbry and Ferriss, 1906) -- valid -- Spiral Pebblesnail
  Cochlodinella Pilsbry and Vanatta, 1898 -- valid
  Cochlodinella poeyana (d'Orbigny, 1841) -- valid -- truncate urocoptid
  Codakia Scopoli, 1777 -- valid
  Codakia cubana Dall, 1901 -- valid -- Cuba lucine
  Codakia orbicularis (Linnaeus, 1758) -- valid -- tiger lucine
  Codakia orbiculata (Montagu, 1808) -- valid -- dwarf tiger lucine
  Codakia pectinella (C. B. Adams, 1852) -- valid -- little-comb lucine
  Coelostemma Dall, 1895 -- valid
  Coelostemma pyrgonasta F. G. Thompson, 1988 -- valid -- Bishop Cap tubesnail
  Collisella Dall, 1871 -- valid
  Collisella edmitchelli (Lipps, 1963) -- valid
  Colubraria Schumacher, 1817 -- valid
  Colubraria lanceolata (Menke, 1828) -- invalid -- arrow dwarf triton
  Colubraria testacea (Morch, 1852) -- valid -- obscure dwarf triton
  Columbella Lamarck, 1799 -- valid
  Columbella mercatoria (Linnaeus, 1758) -- valid -- West Indian dovesnail
  Columbella rusticoides Heilprin, 1886 -- valid -- rusty dovesnail
  Columbellidae Swainson, 1840 -- valid
  Columbellopsis Bucquoy, Dautzenberg and Dollfus, 1882 -- valid
  Columbellopsis nycteis (Duclos, 1846) -- valid -- fenestrate dovesnail
  Columella Westerlund, 1878 -- valid
  Columella columella (von Martens, 1830) -- valid -- mellow column
  Columella edentula (Draparnaud, 1805) -- valid -- toothless column
  Columella simplex (Gould, 1840) -- valid -- high-spire column
  Colus aphelus (Dall, 1890) -- valid -- oblique whelk
  Colus aurantius (Dall, 1907) -- valid -- broad-cord whelk
  Colus barbarinus Dall, 1919 -- valid -- Santa Barbara whelk
  Colus bristolensis Dall, 1919 -- valid
  Colus brunneus (Dall, 1877) -- valid -- brown whelk
  Colus callorhinus (Dall, 1877) -- valid -- strombiform whelk
  Colus capponius Dall, 1919 -- valid
  Colus errones Dall, 1919 -- valid -- wayward whelk
  Colus esychus (Dall, 1907) -- valid
  Colus georgianus (Dall, 1921) -- valid
  Colus griseus (Dall, 1890) -- valid -- gray whelk
  Colus halidonus Dall, 1919 -- valid
  Colus halimeris (Dall, 1919) -- valid
  Colus halli (Dall, 1873) -- invalid
  Colus hallii (Dall, 1873) -- valid
  Colus herendeenii (Dall, 1902) -- valid -- thin-ribbed whelk
  Colus holboellii (Moller, 1842) -- invalid
  Colus holbolli (Moller, 1842) -- valid
  Colus hypolispus (Dall, 1891) -- invalid -- oblique whelk, oblique whelk
  Colus incisus (Dall, 1919) -- valid
  Colus islandicus (Mohr, 1786) -- valid -- Iceland whelk
  Colus jordani (Dall, 1913) -- valid
  Colus kroyeri (Möller, 1842) -- valid -- Arctic whelk
  Colus lividus (Morch, 1862) -- invalid -- bruised whelk
  Colus martensi (Krause, 1885) -- valid
  Colus morditus (Dall, 1919) -- invalid -- shrew whelk
  Colus nobilis (Dall, 1919) -- invalid -- noble whelk
  Colus obesus (A. E. Verrill, 1884) -- invalid -- plump whelk
  Colus oceanodromae (Dall, 1919) -- valid -- seahorse whelk
  Colus ombronius Dall, 1919 -- valid -- shady whelk
  Colus parvus (Tiba, 1980) -- valid
  Colus periscelidus (Dall, 1891) -- valid -- garter whelk
  Colus pubescens (A. E. Verrill, 1882) -- valid -- hairy whelk
  Colus pulcius (Dall, 1919) -- valid
  Colus pygmaeus (Gould, 1841) -- valid -- pygmy whelk
  Colus roseus (Dall, 1877) -- valid -- rosy whelk
  Colus sabinii (J. E. Gray, 1824) -- valid
  Colus severinus (Dall, 1919) -- valid
  Colus spitzbergensis (Reeve, 1835) -- invalid -- thick-ribbed whelk, thick-ribbed whelk
  Colus stejnegeri (Dall, 1884) -- valid
  Colus stimpsoni (Mørch, 1867) -- valid
  Colus syrtensis (Packard, 1867) -- valid
  Colus terraenovae Bouchet and Waren, 1985 -- valid -- ventricose whelk
  Colus timetus (Dall, 1919) -- valid
  Colus trombinus (Dall, 1919) -- valid
  Colus trophius (Dall, 1919) -- valid
  Colus ventricosus (J. E. Gray, 1839) -- invalid -- ventricose whelk
  Colus verkruezeni (Kobelt, 1876) -- valid
  Colus virens (Dall, 1877) -- valid -- green whelk
  Compressidens ophiodon (Dall, 1881) -- valid -- flattened toothshell
  Compressidens pressus (Pilsbry and Sharp, 1897) -- valid -- compressed toothshell
  Compressidens stearnsii Pilsbry and Sharp, 1897 -- valid -- stearns toothshell
  Compsodrillia Woodring, 1928 -- valid
  Compsodrillia eucosmia (Dall, 1889) -- valid
  Compsodrillia haliostrephis (Dall, 1889) -- valid
  Compsodrillia tristicha (Dall, 1889) -- valid
  Compsomyax Stewart, 1930 -- valid
  Compsomyax subdiaphana (Carpenter, 1864) -- valid -- milky venus
  Conchocele Gabb, 1866 -- valid
  Conchocele bisecta (Conrad, 1849) -- valid -- giant cleftclam
  Condylocardiidae F. Bernard, 1897 -- valid
  Conidae Rafinesque, 1815 -- invalid
  Conualevia Collier and Farmer, 1964 -- valid
  Conualevia alba Collier and Farmer, 1964 -- valid -- white smooth-horn doris
  Conualeviidae Collier and Farmer, 1964 -- invalid
  Conus Linnaeus, 1758 -- valid
  Conus amphiurgus Dall, 1889 -- valid
  Conus anabathrum Crosse, 1865 -- valid -- Florida cone
  Conus armiger Crosse, 1858 -- valid -- mace cone
  Conus attenuatus Reeve, 1844 -- valid -- slender cone
  Conus aureonimbosus Petuch, 1987 -- valid
  Conus binghamae Petuch, 1987 -- valid
  Conus californicus Hinds, 1844 -- valid -- California cone
  Conus cancellatus Hwass, 1792 -- valid -- cancellate cone
  Conus daucus Hwass, 1792 -- valid -- carrot cone
  Conus delessertii Recluz, 1843 -- valid
  Conus ermineus Born, 1778 -- valid -- agate cone
  Conus flamingo Petuch, 1980 -- valid -- flamingo cone
  Conus flavescens G. B. Sowerby II, 1834 -- valid -- flame cone
  Conus floridensis G. B. Sowerby II, 1870 -- valid
  Conus glicksteini Petuch, 1987 -- valid
  Conus granulatus Linnaeus, 1758 -- valid -- glory-of-the-Atlantic cone
  Conus harasewychi Petuch, 1987 -- valid
  Conus jaspideus stearnsi Conrad, 1869 -- invalid -- dusky cone
  Conus mcgintyi Pilsbry, 1955 -- valid
  Conus mindanus Hwass, 1792 -- valid -- Bermuda cone
  Conus mus Hwass, 1792 -- valid -- mouse cone
  Conus patae Abbott, 1971 -- valid -- sunrise cone
  Conus pealii Green, 1830 -- valid
  Conus perryae Clench, 1942 -- valid
  Conus rainesae McGinty, 1953 -- valid
  Conus regius Gmelin, 1791 -- valid -- crown cone
  Conus sennottorum Rehder and Abbott, 1951 -- valid -- speckled cone
  Conus spurius Gmelin, 1791 -- valid -- alphabet cone
  Conus stearnsi Conrad, 1869 -- invalid
  Conus stearnsii Conrad, 1869 -- valid
  Conus stimpsoni Dall, 1902 -- valid -- yellow cone
  Conus villepinii P. Fischer and Bernardi, 1857 -- valid
  Conus villepinii fosteri Clench and Aguayo, 1942 -- valid
  Conus villepinii villepinii P. Fischer and Bernardi, 1857 -- valid
  Conus ziczac Megerle von Muhlfeld, 1816 -- valid
  Cooperella atlantica Rehder, 1943 -- valid -- Atlantic cooperclam
  Cooperella subdiaphana (Carpenter, 1864) -- valid -- shiny cooperclam
  Cooperellidae Dall, 1900 -- invalid
  Coralliophaga de Blainville, 1824 -- valid
  Coralliophaga coralliophaga (Gmelin, 1791) -- valid -- coralclam
  Coralliophila H. Adams and A. Adams, 1853 -- valid
  Coralliophila aberrans (C. B. Adams, 1850) -- valid -- globose coralsnail
  Coralliophila aedonia (Watson, 1886) -- valid
  Coralliophila caribaea Abbott, 1958 -- valid -- Caribbean coralsnail
  Coralliophila costata (de Blainville, 1832) -- valid -- California coralsnail
  Coralliophila galea (Reeve, 1846) -- valid -- helmet coralsnail
  Coralliophila lactuca Dall, 1889 -- invalid
  Coralliophila pacei Petuch, 1987 -- valid
  Coralliophila richardi (P. Fischer, 1882) -- valid
  Coralliophila scalariformis (Lamarck, 1822) -- valid -- staircase coralsnail
  Coralliophilidae Chenu, 1859 -- invalid
  Corambe Bergh, 1869 -- valid
  Corambe obscura (A. E. Verrill, 1870) -- valid -- obscure corambe
  Corambidae Bergh, 1871 -- valid
  Corbicula Megerle von Mühlfeld, 1811 -- valid
  Corbicula fluminea (O. F. Müller, 1774) -- valid -- Asian clam
  Corbiculidae Gray, 1847 -- invalid
  Corbula Bruguiere, 1797 -- valid
  Corbula barrattiana C. B. Adams, 1852 -- valid -- barratt corbula, truncate corbula
  Corbula chittyana C. B. Adams, 1852 -- valid -- snubnose corbula
  Corbula contracta Say, 1822 -- valid -- contracted corbula
  Corbula cymella Dall, 1881 -- valid -- wavy corbula
  Corbula dietziana C. B. Adams, 1852 -- valid -- dietz corbula, rose corbula
  Corbula krebsiana C. B. Adams, 1852 -- valid -- Krebs corbula
  Corbula swiftiana C. B. Adams, 1852 -- valid -- swift corbula, radial-ridged corbula
  Corbulidae Lamarck, 1818 -- valid
  Cornirostridae Ponder, 1990 -- valid
  Corolla Dall, 1871 -- valid
  Corolla calceola (A. E. Verrill, 1880) -- valid -- Atlantic corolla
  Corolla intermedia (Tesch, 1903) -- valid
  Corolla ovata (Quoy and Gaimard, 1832) -- valid
  Corolla spectabilis Dall, 1871 -- valid -- spectacular corolla
  Coryphella cooperi Cockerell, 1901 -- invalid -- blue-patch aeolis
  Coryphella diversa (Couthouy, 1839) -- invalid
  Coryphella fusca O'Donoghue, 1921 -- invalid -- predaceous aeolis
  Coryphella gracilis (Alder and Hancock, 1844) -- invalid
  Coryphella iodinea (J. G. Cooper, 1863) -- invalid -- purple aeolis
  Coryphella longicaudata O'donoghue, 1922 -- invalid -- long-tail aeolis
  Coryphella nobilis A. E. Verrill, 1880 -- invalid
  Coryphella pellucida (Alder and Hancock, 1843) -- invalid -- pellucid aeolis
  Coryphella pricei MacFarland, 1966 -- invalid -- smooth-tooth aeolis
  Coryphella rufibranchialis (Johnston, 1832) -- invalid
  Coryphella salmonacea (Couthouy, 1838) -- invalid -- salmon aeolis
  Coryphella subrosacea (Eschscholtz, 1831) -- invalid
  Coryphella trilineata O'Donoghue, 1921 -- invalid -- three-line aeolis
  Coryphella trophina (Bergh, 1894) -- invalid
  Coryphella verrucosa (M. Sars, 1829) -- invalid
  Coryphella verrucosa rufibranchialis (Johnston, 1832) -- invalid -- red-finger aeolis
  Coryphella verrucosa verrucosa (M. Sars, 1829) -- invalid
  Cosmioconcha Dall, 1913 -- valid
  Cosmioconcha calliglypta (Dall and Simpson, 1901) -- valid -- flame dovesnail
  Cosmotriphora Olsson and Harbison, 1953 -- valid
  Cosmotriphora decorata (C. B. Adams, 1850) -- valid -- mottled triphora
  Cosmotriphora melanura (C. B. Adams, 1850) -- valid -- white Atlantic triphora
  Cosmotriphora olivacea (Dall, 1889) -- valid
  Costasiella Pruvoa-Fol, 1951 -- valid
  Costasiella nonatoi Ev. Marcus and Er. Marcus, 1960 -- valid
  Costasiella ocellifera (Simroth, 1895) -- valid -- eyespot costasiella
  Costasiellidae K. B. Clark, 1984 -- valid
  Costellariidae MacDonald, 1860 -- valid
  Costoanachis Sacco, 1890 -- valid
  Costoanachis avara (Say, 1822) -- valid -- greedy dovesnail
  Costoanachis catenata (G. B. Sowerby II, 1844) -- valid -- chain dovesnail
  Costoanachis floridana (Rehder, 1939) -- valid -- Florida dovesnail
  Costoanachis lafresnayi (P. Fischer and Bernardi, 1857) -- valid -- well-ribbed dovesnail
  Costoanachis semiplicata (Stearns, 1873) -- valid -- Gulf dovesnail
  Costoanachis similis (Ravenel, 1861) -- valid
  Costoanachis sparsa (Reeve, 1859) -- valid -- sparse dovesnail
  Couthouyella Bartsch, 1909 -- valid
  Couthouyella striatula (Couthouy, 1838) -- valid -- northern rough wentletrap
  Cranopsis A. Adams, 1860 -- valid
  Cranopsis asturiana (P. Fischer, 1882) -- valid -- Atlantic puncturella
  Cranopsis billsae (Perez Farfante, 1947) -- valid
  Cranopsis cucullata (Gould, 1846) -- valid -- hood puncturella
  Cranopsis decorata (I. M. Cowan and J. H. McLean, 1968) -- valid -- painted puncturella
  Cranopsis erecta (Dall, 1889) -- valid -- erect puncturella
  Cranopsis granulata (Seguenza, 1862) -- valid -- granulate puncturella
  Cranopsis major (Dall, 1891) -- valid -- great puncturella
  Cranopsis multistriata (Dall, 1914) -- valid -- many-rib puncturella
  Crassadoma Bernard, 1986 -- valid
  Crassadoma gigantea (J. E. Gray, 1825) -- valid -- giant rock-scallop
  Crassatellidae Férussac, 1822 -- valid
  Crassedoma Bernard, 1986 -- invalid
  Crassedoma giganteum (J. E. Gray, 1825) -- invalid -- giant rock scallop
  Crassinella Guppy, 1874 -- valid
  Crassinella dupliniana (Dall, 1903) -- valid -- pointed crassinella
  Crassinella lunulata (Conrad, 1834) -- valid -- lunate crassinella
  Crassinella martinicensis (d'Orbigny, 1842) -- valid -- Martinique crassinella
  Crassinella pacifica (C. B. Adams, 1852) -- valid -- Pacific crassinella
  Crassispira Swainson, 1840 -- valid
  Crassispira cubana (Melvill, 1923) -- valid
  Crassispira fuscescens (Reeve, 1845) -- valid
  Crassispira montereyensis Stearns, 1871 -- valid
  Crassispira phasma Schwengel, 1940 -- valid
  Crassispira rhythmica Melvill, 1927 -- valid
  Crassispira semiinflata (Grant and Gale, 1931) -- valid
  Crassostrea Sacco, 1897 -- valid -- cupped oysters, huîtres creuses, ostiones
  Crassostrea ariakensis (Fujita, 1913) -- invalid -- Suminoe oyster
  Crassostrea gigas (Thunberg, 1793) -- invalid -- Pacific cupped oyster, Pacific giant oyster, Pacific oyster
  Crassostrea virginica (Gmelin, 1791) -- valid -- Eastern cupped oyster, American cupped oyster, huître creuse américaine, ostión virgínico, eastern oyster
  Cratena Bergh, 1864 -- valid
  Cratena pilata (Gould, 1870) -- valid
  Creedonia Martins, 1996 -- valid
  Creedonia succinea (Pfeiffer, 1854) -- valid
  Crenella T. Brown, 1827 -- valid
  Crenella decussata (Montagu, 1808) -- valid -- cross-sculpture crenella
  Crenella faba (Muller, 1776) -- valid -- bean crenella
  Crenella fragilis A. E. Verrill, 1885 -- valid -- fragile crenella
  Crenella glandula (Totten, 1834) -- valid -- glandular crenella
  Crenella pectinula (Gould, 1841) -- valid -- little-comb crenella
  Crenella seminuda (Dall, 1897) -- invalid -- partly-sculptured crenella
  Crenella skomma (Schwengel, 1944) -- valid -- joking crenella
  Crepidula Lamarck, 1799 -- valid
  Crepidula aculeata (Gmelin, 1791) -- valid -- spiny slippersnail
  Crepidula adunca G. B. Sowerby I, 1825 -- valid -- hooked slippersnail
  Crepidula convexa Say, 1822 -- valid -- convex slippersnail
  Crepidula fornicata (Linnaeus, 1758) -- valid -- common Atlantic slippersnail
  Crepidula glottidiarum Dall, 1905 -- valid
  Crepidula grandis Middendorff, 1849 -- valid -- great slippersnail
  Crepidula maculosa Conrad, 1846 -- valid -- spotted slippersnail
  Crepidula naticarum Williamson, 1905 -- valid -- cheeky slippersnail
  Crepidula norrisiarum Williamson, 1905 -- valid
  Crepidula nummaria Gould, 1846 -- valid -- western white slippersnail
  Crepidula onyx G. B. Sowerby I, 1824 -- valid -- onyx slippersnail
  Crepidula perforans (Valenciennes, 1846) -- valid -- white slippersnail
  Crepidula plana Say, 1822 -- valid -- eastern white slippersnail
  Crepidula striolata Menke, 1851 -- valid -- ridged slippersnail
  Crepipatella Lesson, 1831 -- valid
  Crepipatella dorsata (Broderip, 1834) -- valid -- Pacific half-slippersnail
  Crepipatella orbiculata (Dall, 1919) -- valid -- round slippersnail
  Creseis Rang, 1828 -- valid
  Creseis acicula (Rang, 1828) -- valid -- straight needle-pteropod
  Creseis virgula (Rang, 1828) -- valid -- curved needle-pteropod
  Crimora Alder and Hancock, 1855 -- valid
  Crimora coneja Er. Marcus, 1961 -- valid -- rabbit doris
  Crockerella Hertlein and Strong, 1951 -- valid
  Crockerella castianira (Dall, 1919) -- valid
  Crockerella conradiana (Gabb, 1869) -- valid
  Crockerella crystallina (Gabb, 1865) -- valid
  Crockerella cymodoce (Dall, 1919) -- valid
  Crockerella eriphyle (Dall, 1919) -- valid
  Crockerella evadne (Dall, 1919) -- valid
  Crockerella lowei (Dall, 1903) -- valid
  Crockerella philodice (Dall, 1919) -- valid
  Crockerella scotti J. H. McLean, 1996 -- valid
  Crockerella tridesmia (S. S. Berry, 1941) -- valid
  Crossata Jousseaume, 1881 -- valid
  Crossata californica (Hinds, 1843) -- valid -- California frogsnail
  Crucibulum Schumacher, 1817 -- valid
  Crucibulum auricula (Gmelin, 1791) -- valid -- West Indian cup-and-saucer
  Crucibulum spinosum (G. B. Sowerby I, 1824) -- valid -- spiny cup-and-saucer
  Crucibulum striatum Say, 1824 -- valid -- striate cup-and-saucer
  Cryoturris Woodring, 1928 -- valid
  Cryoturris cerinella (Dall, 1889) -- valid -- waxy mangelia
  Cryoturris fargoi McGinty, 1955 -- valid
  Cryoturris filifera (Dall, 1881) -- valid
  Cryoturris quadrilineata (C. B. Adams, 1850) -- valid
  Cryptobranchia Middendorff, 1851 -- valid
  Cryptobranchia alba Dall, 1869 -- valid -- white blind limpet
  Cryptobranchia concentrica (Middendorff, 1851) -- valid -- ringed blind limpet
  Cryptochiton Middendorff, 1847 -- valid
  Cryptochiton stelleri (Middendorff, 1847) -- valid -- giant Pacific chiton
  Cryptoconchus Blainville in Burrow, 1815 -- valid
  Cryptoconchus floridanus (Dall, 1889) -- valid -- white-barred chiton
  Cryptomastix Pilsbry, 1939 -- valid
  Cryptomastix devia (Gould, 1846) -- valid -- Puget oregonian
  Cryptomastix germana (Gould, 1851) -- valid -- pygmy oregonian
  Cryptomastix harfordiana (W. G. Binney, 1886) -- valid -- Salmon oregonian
  Cryptomastix hendersoni (Pilsbry, 1928) -- valid -- Columbia oregonian
  Cryptomastix magnidentata (Pilsbry, 1940) -- valid -- Mission Creek oregonian
  Cryptomastix mullani (Bland and J. G. Cooper, 1861) -- valid -- Coeur d'Alene oregonian
  Cryptomastix sanburni (W. G. Binney, 1886) -- valid -- Kingston oregonian
  Cryptomya Conrad, 1848 -- valid
  Cryptomya californica (Conrad, 1837) -- valid -- california softshell clam, California softshell
  Cryptonatica Dall, 1892 -- valid
  Cryptonatica affinis (Gmelin, 1791) -- valid -- Arctic moonsnail
  Cryptonatica aleutica (Dall, 1919) -- valid
  Cryptonatica janthostoma (Deshayes, 1839) -- valid -- purplemouth moonsnail
  Cryptonatica russa (Gould, 1859) -- valid
  Cryptopecten Dall, Bartsch and Rehder, 1938 -- valid
  Cryptopecten phrygium (Dall, 1886) -- valid -- spathate scallop
  Cryptostrea Harry, 1985 -- invalid
  Cryptostrea permollis (G. B. Sowerby II, 1871) -- invalid -- sponge oyster
  Cumanotidae Odhner, 1907 -- valid
  Cumanotus Odhner, 1907 -- valid
  Cumanotus fernaldi T. E. Thompson and G. H. Brown, 1984 -- valid -- polyp aeolis
  Cumberlandia Ortmann, 1912 -- valid
  Cumberlandia monodonta (Say, 1829) -- valid -- spectaclecase
  Cumingia G. B. Sowerby I, 1833 -- valid
  Cumingia californica Conrad, 1837 -- valid -- California semele
  Cumingia coarctata G. B. Sowerby I, 1833 -- valid -- contracted semele
  Cumingia tellinoides (Conrad, 1831) -- valid -- tellin semele
  Cuna Hedley, 1902 -- valid
  Cuna dalli Vanatta, 1904 -- valid -- dall condylclam, trigonal condylclam
  Curtitoma Bartsch, 1941 -- valid
  Curtitoma decussata (Couthuoy, 1839) -- valid
  Curtitoma fiora (Dall, 1919) -- valid
  Curtitoma incisula (A. E. Verrill, 1882) -- valid
  Curtitoma lawrenciana (Dall, 1919) -- valid
  Curtitoma novajasemljensis (Leche, 1878) -- valid
  Curtitoma trevelliana (Turton, 1834) -- valid
  Curtitoma violacea (Mighels and C. B. Adams, 1842) -- valid
  Cuspidaria Nardo, 1840 -- valid
  Cuspidaria alternata (d'Orbigny, 1842) -- valid -- alternate dipperclam
  Cuspidaria glacialis (G. O. Sars, 1878) -- valid -- glacial dipperclam
  Cuspidaria media A. E. Verrill and Bush, 1898 -- valid -- amedian dipperclam, median dipperclam
  Cuspidaria microrhina Dall, 1886 -- valid -- little-snout dipperclam
  Cuspidaria obesa (Loven, 1846) -- valid -- obese dipperclam
  Cuspidaria parapodema Bernard, 1969 -- valid -- California dipperclam
  Cuspidaria pellucida Stimpson, 1853 -- valid -- translucent dipperclam
  Cuspidaria rostrata (Spengler, 1793) -- valid -- rostrate dipperclam
  Cuspidaria subglacialis Dall, 1913 -- valid -- subglacial dipperclam
  Cuspidariidae Dall, 1886 -- valid
  Cuthona Alder and Hancock, 1855 -- valid
  Cuthona abronia (MacFarland, 1966) -- valid -- colorful cuthona
  Cuthona albocrusta (MacFarland, 1966) -- valid -- white-crust cuthona
  Cuthona caerulea (Montagu, 1804) -- valid
  Cuthona cocoachroma Williams and Gosliner, 1979 -- valid -- brown cuthona
  Cuthona concinna (Alder and Hancock, 1843) -- valid
  Cuthona divae (Er. Marcus, 1961) -- valid -- rose-pink cuthona
  Cuthona flavovulta (MacFarland, 1966) -- valid -- yellowish cuthona
  Cuthona fulgens (MacFarland, 1966) -- valid -- black-and-yellow cuthona
  Cuthona hamanni Behrens, 1987 -- valid
  Cuthona lagunae (O'Donoghue, 1926) -- valid -- orange-face cuthona
  Cuthona nana (Alder and Hancock, 1842) -- valid
  Cuthona perca (Er. Marcus, 1958) -- valid -- lake merritt cuthona
  Cuthona phoenix Gosliner, 1981 -- valid -- bornagain cuthona
  Cuthona punicea Millen, 1986 -- valid
  Cuthona pustulata (Alder and Hancock, 1854) -- valid
  Cuthona rolleri Behrens and Gosliner, 1988 -- valid
  Cuthona tina (Er. Marcus, 1957) -- valid
  Cuthona veronica (A. E. Verrill, 1860) -- invalid
  Cuthona veronicae (A. E. Verrill, 1880) -- valid
  Cuthona virens (MacFarland, 1966) -- valid -- green cuthona
  Cuthona viridis (Forbes, 1840) -- valid
  Cuvierina Boas, 1886 -- valid
  Cuvierina columnella (Rang, 1827) -- valid -- cigar pteropod
  Cyathodonta Conrad, 1849 -- valid
  Cyathodonta pedroana Dall, 1915 -- valid -- San Pedro thraciid
  Cyclinella Dall, 1902 -- valid
  Cyclinella tenuis (Recluz, 1852) -- valid -- thin cyclinella
  Cyclocardia Conrad, 1867 -- valid
  Cyclocardia bailyi (J. Q. Burch, 1944) -- valid -- bumpy cyclocardia
  Cyclocardia barbarensis (Stearns, 1891) -- valid -- Santa Barbara cyclocardia
  Cyclocardia borealis (Conrad, 1831) -- valid -- northern cyclocardia
  Cyclocardia crassidens (Broderip and G. B. Sowerby I, 1829) -- valid -- thick cyclocardia
  Cyclocardia crebricostata (Krause, 1885) -- valid -- many-ribbed cyclocardia, many-rib cyclocardia
  Cyclocardia gouldii (Dall, 1903) -- valid -- Gould cyclocardia
  Cyclocardia incisa (Dall, 1903) -- valid -- cut cyclocardia
  Cyclocardia novangliae (E. S. Morse, 1869) -- valid -- New England cyclocardia
  Cyclocardia ovata (Riabinina, 1952) -- valid -- ovate cyclocardia
  Cyclocardia umnaka (Willett, 1932) -- valid -- umnak cyclocardia, Aleutian cyclocardia
  Cyclocardia ventricosa (Gould, 1850) -- valid -- stout cyclocardia
  Cyclonaias Pilsbry in Ortmann & Walker, 1922 -- valid
  Cyclonaias tuberculata (Rafinesque, 1820) -- valid -- purple wartyback
  Cyclopecten A. E. Verrill, 1897 -- valid
  Cyclopecten barbarensis Grau, 1959 -- valid -- santa barbara scallop, Santa Barbara glass-scallop
  Cyclopecten catalinensis (Willett, 1931) -- valid -- catalina scallop, Catalina glass-scallop
  Cyclopecten davidsoni (Dall, 1897) -- valid -- salmon glass-scallop
  Cyclopecten greenlandicus (G. B. Sowerby II, 1842) -- valid -- Greenland glass-scallop
  Cyclopecten imbrifer (Loven, 1847) -- valid -- shingle glass-scallop
  Cyclopecten leptaleum (A. E. Verrill, 1884) -- valid
  Cyclopecten nanus A. E. Verrill and Bush, 1897 -- valid -- adwarf scallop, dwarf glass-scallop
  Cyclopecten reticulum (Dall, 1886) -- valid
  Cyclopecten ringnesius (Dall, 1924) -- valid -- Ringnes glass-scallop
  Cyclopecten thalassinus (Dall, 1886) -- valid -- cancellate dwarf scallop, costate glass-scallop
  Cyclostrema Marryat, 1818 -- valid
  Cyclostrema cancellatum Marryat, 1818 -- valid -- cancellate cyclostreme
  Cyclostrema huesonicum (Dall, 1927) -- valid -- Key West cyclostreme
  Cyclostrema tortuganum (Dall, 1927) -- valid -- Tortugas cyclostreme
  Cyclostremella Bush, 1897 -- valid
  Cyclostremella concordia Bartsch, 1920 -- valid
  Cyclostremella humilis Bush, 1897 -- valid
  Cyclostremiscus Pilsbry and Olsson, 1945 -- valid
  Cyclostremiscus beauii (P. Fischer, 1857) -- valid
  Cyclostremiscus cubanus (Pilsbry and Aguayo, 1933) -- valid
  Cyclostremiscus jeannae Pilsbry and McGinty, 1946 -- valid
  Cyclostremiscus pentagonus (Gabb, 1873) -- valid
  Cyclostremiscus suppressus (Dall, 1889) -- valid -- suppressed vitrinella
  Cyclothyca Stearns, 1891 -- valid
  Cyclothyca pacei Petuch, 1987 -- valid
  Cyerce Bergh, 1870 -- valid
  Cyerce antillensis Engel, 1927 -- valid -- Antilles glass-slug
  Cyerce cristallina (Trinchese, 1881) -- valid -- harlequin glass-slug
  Cylichna Loven, 1846 -- valid
  Cylichna alba (T. Brown, 1827) -- valid -- white chalice-bubble
  Cylichna attonsa Carpenter, 1865 -- valid
  Cylichna diegensis (Dall, 1919) -- valid -- San Diego chalice-bubble
  Cylichna eburnea A. E. Verrill, 1885 -- valid -- ivory chalice-bubble
  Cylichna gouldii (Couthouy, 1839) -- valid
  Cylichna linearis Jeffreys, 1867 -- valid -- lined chalice-bubble
  Cylichna nucleolus (Reeve, 1855) -- valid -- kernel chalice-bubble
  Cylichna occulta (Mighels and C. B. Adams, 1842) -- valid -- concealed chalice-bubble
  Cylichnidae H. Adams and A. Adams, 1854 -- valid
  Cylindrobulla P. Fischer, 1857 -- valid
  Cylindrobulla beauii P. Fischer, 1857 -- valid
  Cylindrobullidae Thiele, 1931 -- valid
  Cymakra Gardner, 1937 -- valid
  Cymakra aspera (Carpenter, 1864) -- valid
  Cymakra gracilior (Tryon, 1884) -- valid
  Cymatioa Berry, 1964 -- valid
  Cymatioa electilis (S. S. Berry, 1963) -- valid -- wavy-edged kellyclam
  Cymatium Roding, 1798 -- valid
  Cymatium aquatile (Reeve, 1844) -- valid
  Cymatium comptum (A. Adams, 1855) -- valid -- dwarf triton
  Cymatium corrugatum (Lamarck, 1816) -- valid
  Cymatium corrugatum amictum (Reeve, 1844) -- valid
  Cymatium corrugatum krebsii (Morch, 1877) -- valid
  Cymatium cynocephalum (Lamarck, 1816) -- valid -- doghead triton
  Cymatium femorale (Linnaeus, 1758) -- valid -- angular triton
  Cymatium labiosum (W. Wood, 1828) -- valid -- lip triton
  Cymatium martinianum (d'Orbigny, 1846) -- valid -- hairy triton
  Cymatium mundum (Gould, 1849) -- valid
  Cymatium muricinum (Roding, 1798) -- valid -- knobbed triton
  Cymatium nicobaricum (Roding, 1798) -- valid -- goldmouth triton
  Cymatium occidentale (Morch, 1877) -- valid
  Cymatium parthenopeum (von Salis, 1793) -- valid -- giant triton
  Cymatium pfeifferianum (Reeve, 1844) -- valid
  Cymatium ridleyi (E. A. Smith, 1890) -- valid -- twisted triton
  Cymatium tenuiliratum (Lischke, 1873) -- valid -- slender triton
  Cymatium vespaceum (Lamarck, 1822) -- valid
  Cymatoica Dall, 1889 -- valid
  Cymatoica orientalis (Dall, 1890) -- valid -- western tellin
  Cymatosyrinx Dall, 1889 -- valid
  Cymatosyrinx hemphilli (Stearns, 1871) -- valid
  Cymatosyrinx johnsoni Arnold, 1903 -- valid
  Cymbovula Cate, 1974 -- valid
  Cymbovula acicularis (Lamarck, 1810) -- valid -- West Indian simnia
  Cymbulia Peron and Lesueur, 1810 -- valid
  Cymbulia peronii de Blainville, 1818 -- valid
  Cymbuliidae Gray, 1840 -- valid
  Cyphoma Roding, 1798 -- valid
  Cyphoma alleneae Cate, 1973 -- valid
  Cyphoma aureocinctum (Dall, 1889) -- valid -- gold-line cyphoma
  Cyphoma gibbosum (Linnaeus, 1758) -- valid -- flamingo tongue
  Cyphoma lindae Petuch, 1987 -- valid
  Cyphoma mcgintyi Pilsbry, 1939 -- valid
  Cyphoma mcgintyi mcgintyi Pilsbry, 1939 -- valid
  Cyphoma mcgintyi robustior F. M. Bayer, 1941 -- valid
  Cyphoma rhomba Cate, 1978 -- valid -- bullroarer cyphoma
  Cyphoma sedlaki Cate, 1976 -- valid
  Cyphoma signatum Pilsbry and McGinty, 1939 -- valid -- fingerprint cyphoma
  Cypraea spurca acicularis Gmelin, 1791 -- invalid -- atlantic yellow cowrie
  Cypraecassis Stutchbury, 1837 -- valid
  Cypraecassis testiculus (Linnaeus, 1758) -- valid -- reticulate cowrie-helmet
  Cypraeidae Rafinesque, 1815 -- valid
  Cyprogenia Agassiz, 1852 -- valid
  Cyprogenia aberti (Conrad, 1850) -- valid -- western fanshell
  Cyprogenia stegaria (Rafinesque, 1820) -- valid -- fanshell
  Cyrenoida Joannis, 1835 -- valid
  Cyrenoida floridana (Dall, 1896) -- valid -- Florida marshclam
  Cyrenoididae H. and A. Adams, 1857 -- valid
  Cyrtodaria Reuss, 1801 -- valid
  Cyrtodaria kurriana Dunker, 1861 -- valid -- Kurr propellerclam
  Cyrtodaria siliqua (Spengler, 1793) -- valid -- northern propellerclam
  Cyrtonaias Crosse & Fischer, 1894 -- valid
  Cyrtonaias tampicoensis (Lea, 1838) -- valid -- Tampico pearlymussel, Tampico pearly mussel
  Cyrtopleura Tryon, 1862 -- valid
  Cyrtopleura costata (Linnaeus, 1758) -- valid -- angelwing
  Cystiscidae Stimpson, 1865 -- valid
  Cystiscus Stimpson, 1865 -- valid
  Cystiscus jewetti (Carpenter, 1856) -- invalid
  Cystiscus politulus (Dall, 1919) -- invalid -- polite marginella
  Cystiscus politus (Carpenter, 1857) -- valid -- polished marginella
  Cystiscus subtrigonus (Carpenter, 1864) -- invalid -- triangular marginella
  Cythnia Carpenter, 1864 -- valid
  Cythnia albida Carpenter, 1864 -- valid
  Dacrydium Torell, 1859 -- valid
  Dacrydium elegantulum Soot-Ryen, 1955 -- valid -- elegant mussel
  Dacrydium elegantulum hendersoni Salas and Gofas, 1997 -- valid
  Dacrydium pacificum Dall, 1916 -- valid -- Pacific glassy-mussel
  Dacrydium vitreum (Moller, 1842) -- valid -- glassy mussel, Arctic glassy-mussel
  Daedalochila Beck, 1837 -- valid
  Daedalochila auriculata (Say, 1818) -- valid -- Ocala liptooth
  Daedalochila auriformis (Bland, 1859) -- valid -- rockpile liptooth
  Daedalochila avara (Say, 1818) -- valid -- Florida liptooth
  Daedalochila chisosensis (Pilsbry, 1936) -- valid -- Chisos liptooth
  Daedalochila delecta (Hubricht, 1976) -- valid -- Gulf Hammock liptooth
  Daedalochila hausmani (Jackson, 1948) -- valid -- Dixie liptooth
  Daedalochila hippocrepis (Pfeiffer, 1848) -- valid -- horseshoe liptooth
  Daedalochila leporina (Gould, 1848) -- valid -- Gulf Coast liptooth
  Daedalochila peninsulae (Pilsbry, 1940) -- valid -- St. Johns liptooth
  Daedalochila polita (Pilsbry and Hinkley, 1907) -- valid -- suave liptooth
  Daedalochila postelliana (Bland, 1859) -- valid -- coastal liptooth
  Daedalochila scintilla (Pilsbry and Hubricht, 1962) -- valid
  Daedalochila subclausa (Pilsbry, 1899) -- valid -- Suwannee liptooth
  Daedalochila triodontoides (Bland, 1861) -- valid -- marsh liptooth
  Daedalochila uvulifera (Shuttleworth, 1852) -- valid -- peninsula liptooth
  Daphnella Hinds, 1844 -- valid
  Daphnella clathrata Gabb, 1865 -- valid
  Daphnella corbicula Dall, 1889 -- valid
  Daphnella lymneiformis (Kiener, 1840) -- valid -- volute daphnelle
  Daphnella margaretae Lyons, 1972 -- valid
  Daphnella reticulosa Dall, 1889 -- valid
  Daphnella retifera Dall, 1889 -- valid
  Daphnella stegeri McGinty, 1955 -- valid
  Dasyscias F. G. Thompson and Hershler, 1991 -- valid
  Dasyscias franzi F. G. Thompson and Hershler, 1991 -- valid -- Shaggy Ghostsnail
  Decoriatrivia Cate, 1979 -- valid
  Decoriatrivia ritteri (Raymond, 1903) -- valid
  Delectopecten Stewart, 1930 -- valid
  Delectopecten randolphi (Dall, 1897) -- invalid -- Randolph scallop
  Delectopecten vancouverensis (Whiteaves, 1893) -- valid -- Vancouver scallop
  Delectopecten vitreus (Gmelin, 1791) -- valid -- vitreous scallop
  Dendostrea Swainson, 1835 -- valid
  Dendostrea frons (Linnaeus, 1758) -- valid -- frons oyster, frond oyster
  Dendrodorididae Pruvot-Fol, 1935 -- invalid
  Dendrodoris Ehrenberg, 1831 -- valid
  Dendrodoris fulva (MacFarland, 1905) -- valid -- yellow porostome
  Dendrodoris krebsii (Morch, 1863) -- valid
  Dendrodoris nigromaculata (Cockerell, 1905) -- valid -- black-spot porostome
  Dendrodoris warta Ev. Marcus and Er. Marcus, 1976 -- valid
  Dendronotidae Gray, 1857 -- invalid
  Dendronotus Alder and Hancock, 1845 -- valid
  Dendronotus albopunctatus Robilliard, 1972 -- valid
  Dendronotus albus MacFarland, 1966 -- valid -- white frond-aeolis
  Dendronotus dalli Bergh, 1879 -- valid
  Dendronotus diversicolor Robilliard, 1970 -- valid -- multicolor frond-aeolis
  Dendronotus frondosus (Ascanius, 1774) -- valid -- frond-aeolis
  Dendronotus iris J. G. Cooper, 1863 -- valid -- giant frond-aeolis
  Dendronotus robustus A. E. Verrill, 1870 -- valid -- robust frond-aeolis
  Dendronotus rufus O'Donoghue, 1921 -- valid -- red frond-aeolis
  Dendronotus subramosus MacFarland, 1966 -- valid -- stubby frond-aeolis
  Dendropoma Morch, 1861 -- valid
  Dendropoma corrodens (d'Orbigny, 1842) -- valid -- ringed wormsnail
  Dendropoma exsertum (Dall, 1881) -- valid
  Dendropoma irregulare (d'Orbigny, 1842) -- valid -- irregular wormsnail
  Dendropoma lituella (Morch, 1861) -- valid -- flat wormsnail
  Dendropoma rastrum (Morch, 1861) -- valid -- California wormsnail
  Dentaliida da Costa, 1776 -- valid
  Dentaliidae Children, 1834 -- valid
  Dentalium americanum Chenu, 1843 -- valid -- American tuskshell
  Dentalium gouldii Dall, 1889 -- valid -- gould tuskshell
  Dentalium laqueatum A. E. Verrill, 1885 -- valid -- reticulate tuskshell
  Dentalium neohexagonum Sharp and Pilsbry, 1897 -- valid -- hexagon tuskshell
  Dentalium vallicolens Raymond, 1904 -- valid -- trench tuskshell
  Dentimargo Cossmann, 1899 -- valid
  Dentimargo aureocinctus (Stearns, 1872) -- valid -- gold-line marginella
  Dentimargo eburneolus (Conrad, 1834) -- valid -- tan marginella
  Dentimargo idiochila (Schwengel, 1943) -- valid
  Dentimargo reductus (Bavay, 1922) -- valid
  Dentimargo smithii (A. E. Verrill, 1885) -- valid
  Dentistyla Dall, 1889 -- valid
  Dentistyla asperrima (Dall, 1881) -- valid -- rough topsnail
  Depressiscala de Boury, 1909 -- valid
  Depressiscala nautlae (Morch, 1874) -- valid -- slender wentletrap
  Depressiscala nitidella (Dall, 1889) -- valid -- mottled wentletrap
  Depressiscala polita (G. B. Sowerby II, 1844) -- valid -- polished wentletrap
  Dermatomya Dall, 1889 -- valid
  Dermatomya buttoni Dall, 1916 -- valid -- yellow poromya
  Dermatomya mactroides (Dall, 1889) -- valid -- trigonal poromya
  Dermomurex di Monterosato, 1890 -- valid
  Dermomurex abyssicola (Crosse, 1865) -- valid
  Dermomurex elizabethae (McGinty, 1940) -- valid
  Dermomurex glicksteini Petuch, 1987 -- valid
  Dermomurex pacei Petuch, 1988 -- valid
  Dermomurex pauperculus (C. B. Adams, 1850) -- valid -- beggar aspella
  Deroceras Rafinesque, 1820 -- valid
  Deroceras hesperium Pilsbry, 1944 -- valid -- evening field slug, evening fieldslug
  Deroceras heterura Pilsbry, 1944 -- valid -- false marsh slug, marsh slug
  Deroceras laeve (Muller, 1774) -- valid -- meadow slug
  Deroceras monentolophus Pilsbry, 1944 -- valid -- one-ridge field slug, one-ridge fieldslug
  Deroceras panormitanum (Lessona and Pollonera, 1882) -- valid -- longneck fieldslug
  Deroceras reticulatum (Muller, 1774) -- valid -- gray field slug, gray fieldslug
  Desmopteridae Dall, 1921 -- invalid
  Desmopterus Chun, 1889 -- valid
  Desmopterus pacificus Essenberg, 1919 -- valid
  Desmopterus papilio Chun, 1889 -- valid
  Diacavolinia Van der Spoel, 1987 -- valid
  Diacavolinia deblainvillei van der Spoel, Bleeker and Kobayashi, 1993 -- valid
  Diacavolinia deshayesi van der Spoel, Bleeker and Kobayashi, 1993 -- valid
  Diacavolinia elegans van der Spoel, Bleeker and Kobayashi, 1993 -- valid
  Diacavolinia ovalis van der Spoel, Bleeker and Kobayashi, 1993 -- valid
  Diacria Gray, 1847 -- valid
  Diacria danae van Leyen and van der Spoel, 1982 -- valid
  Diacria maculata Bleeker and van der Spoel, 1988 -- valid
  Diacria major (Boas, 1886) -- valid
  Diacria rampali Dupont, 1979 -- valid
  Diacria trispinosa (de Blainville, 1821) -- valid -- three-spine cavoline
  Diaphana Brown, 1827 -- valid
  Diaphana brunnea Dall, 1919 -- valid -- brown paper-bubble, brown paperbubble
  Diaphana californica Dall, 1919 -- valid -- california paper-bubble, California paperbubble
  Diaphana minuta Brown, 1827 -- valid -- arctic paper-bubble, weak paper-bubble, Arctic paperbubble
  Diaphanidae Odhner, 1914 -- valid
  Diaphorodoris Iredale and O'Donoghue, 1923 -- valid
  Diaphorodoris lirulatocauda Millen, 1985 -- valid
  Diaulula Bergh, 1879 -- valid
  Diaulula sandiegensis (J. G. Cooper, 1863) -- valid -- ringed doris
  Didianema Woodring, 1928 -- valid
  Didianema pauli Pilsbry and McGinty, 1945 -- valid
  Dimya Roualt, 1848 -- valid
  Dimya argentea Dall, 1886 -- valid -- silver dimyid
  Dimya californiana S. S. Berry, 1936 -- valid -- California dimyid
  Dimyidae P. Fischer, 1886 -- valid
  Dinocardium Dall, 1900 -- valid
  Dinocardium robustum (Lightfoot, 1786) -- valid -- Atlantic giant cockle
  Diodora J. E. Gray, 1821 -- valid
  Diodora aguayoi Perez Farfante, 1943 -- valid
  Diodora arcuata (G. B. Sowerby II, 1862) -- valid -- arcuate keyhole limpet
  Diodora arnoldi J. H. McLean, 1966 -- valid -- neat-rib keyhole limpet
  Diodora aspera (Rathke, 1833) -- valid -- rough keyhole limpet
  Diodora bermudensis (Dall and Bartsch, 1911) -- valid -- Bermuda keyhole limpet
  Diodora cayenensis (Lamarck, 1822) -- valid -- Cayenne keyhole limpet
  Diodora dysoni (Reeve, 1850) -- valid
  Diodora fluviana (Dall, 1889) -- valid -- Gulf Stream keyhole limpet
  Diodora jaumei Aguayo and Rehder, 1936 -- valid
  Diodora listeri (d'Orbigny, 1842) -- valid
  Diodora meta (von Ihering, 1927) -- valid
  Diodora minuta (Lamarck, 1822) -- valid -- dwarf keyhole limpet
  Diodora sayi (Dall, 1889) -- valid
  Diodora tanneri (A. E. Verrill, 1882) -- valid
  Diodora variegata G. B. Sowerby II, 1862 -- valid -- variegate keyhole limpet
  Diodora viridula (Lamarck, 1822) -- valid -- green keyhole limpet
  Diodora wetmorei Perez Farfante, 1945 -- valid
  Diplodonta Bronn, 1831 -- valid
  Diplodonta aleutica Dall, 1901 -- valid -- Aleutian diplodon
  Diplodonta candeana (d'Orbigny, 1842) -- valid -- Cande diplodon
  Diplodonta impolita S. S. Berry, 1953 -- valid -- rough diplodon
  Diplodonta notata Dall and Simpson, 1901 -- valid -- marked diplodon
  Diplodonta nucleiformis Wagner, 1838 -- valid -- nut-shaped diplodon, nut diplodon
  Diplodonta orbella (Gould, 1851) -- valid -- orb diplodon
  Diplodonta punctata (Say, 1822) -- valid -- Atlantic diplodon
  Diplodonta semiaspera Philippi, 1836 -- valid -- pimpled diplodon
  Diplodonta sericata (Reeve, 1850) -- valid -- flat diplodon
  Diplodonta soror C. B. Adams, 1852 -- valid -- sister diplodon
  Diplodonta subglobosa C. B. Adams, 1852 -- valid -- subglobose diplodon
  Diplodonta venezuelensis Dunker, 1848 -- valid -- Venezuela diplodon
  Diplodonta verrilli Dall, 1900 -- valid -- verrill diplodon, inflated diplodon
  Diplosolenodes Thome, 1976 -- valid
  Diplosolenodes occidentale (Guilding, 1825) -- valid -- spotted leatherleaf
  Diplothyra Tryon, 1862 -- valid
  Diplothyra smithii Tryon, 1862 -- valid -- oyster piddock
  Dirona MacFarland, 1905 -- valid
  Dirona albolineata MacFarland, 1905 -- valid -- white-line dirona
  Dirona aurantia Hurst, 1966 -- valid -- golden dirona
  Dirona picta MacFarland, 1905 -- valid -- painted dirona
  Dironidae Eliot, 1910 -- valid
  Discidae Thiele, 1931 -- valid
  Discodorididae Bergh, 1891 -- valid
  Discodoris Bergh, 1877 -- valid
  Discodoris alba White, 1952 -- valid
  Discodoris evelinae Er. Marcus, 1955 -- valid
  Discodoris mortenseni Ev. Marcus and Er. Marcus, 1963 -- valid
  Discodoris phoca Ev. Marcus and Er. Marcus, 1967 -- valid
  Discodoris purcina Ev. Marcus and Er. Marcus, 1967 -- valid
  Disconaias Crosse & Fischer, 1894 -- valid
  Disconaias salinasensis (Simpson, 1908) -- invalid -- Salina mucket
  Discotectonica Marwick, 1931 -- valid
  Discotectonica discus (Philippi, 1844) -- valid -- keeled sundial
  Discurria Lindberg, 1988 -- valid
  Discurria insessa (Hinds, 1842) -- valid -- seaweed limpet
  Discus Fitzinger, 1833 -- valid
  Discus brunsoni S. S. Berry, 1955 -- valid -- lake disc
  Discus bryanti (Harper, 1881) -- valid -- saw-tooth disc, sawtooth disc
  Discus catskillensis (Pilsbry, 1896) -- valid -- angular disc
  Discus clappi (Pilsbry, 1924) -- valid -- channelled disc
  Discus cronkhitei (Newcomb, 1865) -- invalid -- forest disc
  Discus macclintocki (F. C. Baker, 1928) -- valid -- iowa pleistocene snail, Pleistocene disc
  Discus marmorensis H. B. Baker, 1932 -- valid -- marbled disc
  Discus nigrimontanus (Pilsbry, 1924) -- valid -- Black Mountain disc
  Discus patulus (Deshayes, 1830) -- valid -- domed disc
  Discus rotundatus (Muller, 1774) -- valid -- rotund disc
  Discus selenitoides (Pilsbry, 1890) -- valid -- file disc
  Discus shimekii (Pilsbry, 1890) -- valid -- striate disc
  Discus whitneyi (Newcomb, 1864) -- valid -- forest disc
  Distorsio Roding, 1798 -- valid
  Distorsio clathrata (Lamarck, 1816) -- valid -- Atlantic distorsio
  Distorsio constricta Broderip, 1833 -- valid
  Distorsio constricta macgintyi Emerson and Puffer, 1953 -- invalid
  Distorsio constricta mcgintyi Emerson and Puffer, 1953 -- valid
  Distorsio perdistorta Fulton, 1938 -- valid -- hunchback distorsio
  Divalinga Chavan, 1951 -- valid
  Divalinga quadrisulcata (d'Orbigny, 1842) -- valid -- cross-hatched lucine
  Divaricella von Martens, 1880 -- valid
  Divaricella dentata (W. Wood, 1815) -- valid -- dentate lucine
  Divariscintilla Powell, 1932 -- valid
  Divariscintilla cordiformis P. M. Mikkelsen and Bieler, 1992 -- valid -- heart-shaped galeommatid
  Divariscintilla luteocrinita P. M. Mikkelsen and Bieler, 1992 -- valid -- yellow-tentacled galeommatid
  Divariscintilla octotentaculata P. M. Mikkelsen and Bieler, 1992 -- valid -- eight-tentacle galeommatid
  Divariscintilla troglodytes P. M. Mikkelsen and Bieler, 1989 -- valid -- hole-dwelling galeommatid
  Divariscintilla yoyo P. M. Mikkelsen and Bieler, 1989 -- valid -- yoyo galeommatid
  Dolabrifera Gray, 1847 -- valid
  Dolabrifera dolabrifera (Rang, 1828) -- valid -- warty seacat
  Dolicholatirus Bellardi, 1884 -- valid
  Dolicholatirus cayohuesonicus (Sowerby, 1878) -- invalid -- Key West latirus
  Dolicholatirus pauli (McGinty, 1955) -- valid -- slender latirus
  Donacidae J. Fleming, 1828 -- valid
  Donax Linnaeus, 1758 -- valid
  Donax californicus Conrad, 1837 -- valid -- California beanclam
  Donax fossor Say, 1822 -- valid -- fossor coquina
  Donax gouldii Dall, 1921 -- valid -- Gould beanclam
  Donax variabilis Say, 1822 -- valid -- variable coquina
  Dondersia Hubrecht, 1888 -- valid
  Dondersiidae -- valid
  Dondice Er. Marcus, 1958 -- valid
  Dondice occidentalis (Engel, 1925) -- valid -- western dondice
  Dorididae Rafinesque, 1815 -- valid
  Doriopsilla Bergh, 1880 -- valid
  Doriopsilla albopunctata (J. G. Cooper, 1863) -- valid -- salted yellow doris, white-spot porostome
  Doriopsilla pharpa Er. Marcus, 1961 -- valid -- lemon drop
  Doris Linnaeus, 1758 -- valid
  Doris odonoghuei Steinberg, 1963 -- valid
  Doris verrucosa Linnaeus, 1758 -- valid -- sponge slug
  Dosinia Scopoli, 1777 -- valid
  Dosinia discus (Reeve, 1850) -- valid -- disk dosinia
  Dosinia elegans (Conrad, 1843) -- valid -- elegant dosinia
  Doto Oken, 1815 -- valid
  Doto amyra Er. Marcus, 1961 -- valid -- hammerhead doto
  Doto caramella Er. Marcus, 1957 -- valid
  Doto chica Ev. Marcus and Er. Marcus, 1960 -- valid
  Doto columbiana O'Donoghue, 1921 -- valid -- British Columbia doto
  Doto coronata (Gmelin, 1791) -- valid -- crown doto
  Doto divae Ev. Marcus and Er. Marcus, 1960 -- valid
  Doto doerga Ev. Marcus and Er. Marcus, 1963 -- valid
  Doto formosa A. E. Verrill, 1875 -- valid
  Doto kya Er. Marcus, 1961 -- valid -- dark doto
  Doto lancei Ev. Marcus and Er. Marcus, 1967 -- valid
  Doto pita Er. Marcus, 1955 -- valid
  Doto uva Er. Marcus, 1955 -- valid
  Dotoidae -- invalid
  Dreissena Beneden, 1835 -- valid
  Dreissena bugensis Andrusov, 1897 -- valid -- quagga mussel
  Dreissena polymorpha (Pallas, 1771) -- valid -- zebra mussel
  Dreissenidae Gray, 1840 -- valid
  Drepanotrema Crosse and P. Fischer, 1880 -- valid
  Drepanotrema aeruginosus (Morelet, 1851) -- valid -- rusty rams-horn
  Drepanotrema cimex (Moricand, 1839) -- valid -- ridged rams-horn
  Drepanotrema kermatoides (d'Orbigny, 1835) -- valid -- crested rams-horn
  Drillia Gray, 1838 -- valid
  Drillia acurugata Dall, 1890 -- valid -- rough drillia
  Drillia albicoma Dall, 1889 -- valid
  Drillia canna Dall, 1889 -- valid
  Drillia cydia (Bartsch, 1943) -- valid
  Drillia wolfei Tippett, 1995 -- valid
  Drilliidae Olsson, 1964 -- valid
  Drilliola Locard, 1897 -- valid
  Drilliola loprestiana (Calcara, 1841) -- valid
  Dromus Simpson, 1900 -- valid
  Dromus dromas (Lea, 1834) -- valid -- dromedary pearlymussel, dromedary pearly mussel
  Dryachloa F. G. Thompson and H. G. Lee, 1980 -- valid
  Dryachloa dauca F. G. Thompson and H. G. Lee, 1980 -- valid -- carrot glass
  Drymaeus Albers, 1850 -- valid
  Drymaeus dominicus (Reeve, 1850) -- valid -- master treesnail
  Drymaeus dormani (W. G. Binney, 1857) -- valid -- manatee treesnail
  Drymaeus multilineatus (Say, 1825) -- valid -- lined treesnail
  Ebalidae Warén, 1995 -- invalid
  Elachisima Dall, 1918 -- invalid
  Elachisima floridana (Rehder, 1943) -- invalid
  Elachisina Dall, 1918 -- valid
  Elachisina floridana (Rehder, 1943) -- valid
  Elachisina globuloides (Waren, 1972) -- valid
  Elachisina grippi Dall, 1918 -- valid
  Elachisinidae Ponder, 1985 -- valid
  Elaeocyma Dall, 1918 -- valid
  Elaeocyma empyrosia (Dall, 1899) -- valid
  Elimia H. Adams and A. Adams, 1854 -- valid
  Elimia acuta (Lea, 1831) -- valid -- Acute Elimia
  Elimia alabamensis (Lea, 1861) -- valid -- Mud Elimia
  Elimia albanyensis (Lea, 1864) -- valid -- Black-crest Elimia
  Elimia ampla (Anthony, 1854) -- valid -- Ample Elimia
  Elimia annettae (Goodrich, 1941) -- valid -- Lilyshoals Elimia
  Elimia arachnoidea (Anthony, 1854) -- valid -- Spider Elimia
  Elimia aterina (Lea, 1863) -- valid -- Coal Elimia
  Elimia athearni (Clench and Turner, 1956) -- valid -- Knobby Elimia
  Elimia bellacrenata (Haldeman, 1841) -- valid -- Princess Elimia
  Elimia bellula (Lea, 1861) -- valid -- Walnut Elimia
  Elimia bentoniensis (Lea, 1862) -- invalid -- rusty elimia
  Elimia boykiniana (Lea, 1840) -- valid -- Flaxen Elimia
  Elimia brevis (Reeve, 1860) -- valid -- short-spire elimia, Short Spire Elimia
  Elimia caelatura (Reeve, 1860) -- valid -- rippled elimia, Savannah Elimia
  Elimia cahawbensis (Lea, 1861) -- valid -- Cahaba Elimia
  Elimia capillaris (Lea, 1861) -- valid -- Spindle Elimia
  Elimia carinifera (Lamarck, 1822) -- valid -- Sharp-crest Elimia
  Elimia catenaria (Say, 1822) -- valid -- Gravel Elimia
  Elimia catenoides (Lea, 1842) -- valid -- Lirate Elimia
  Elimia chiltonensis (Goodrich, 1941) -- valid -- Prune Elimia
  Elimia clara (Anthony, 1854) -- valid -- Riffle Elimia
  Elimia clausa (Lea, 1861) -- valid -- Closed Elimia
  Elimia clavaeformis (Lea, 1841) -- valid -- Club Elimia
  Elimia clenchi (Goodrich, 1924) -- valid -- Slackwater Elimia
  Elimia comalensis (Pilsbry, 1890) -- valid -- Balcones Elimia
  Elimia comma (Conrad, 1834) -- valid -- Hispid Elimia
  Elimia costifera (Reeve, 1861) -- valid -- Corded Elimia
  Elimia crenatella (Lea, 1860) -- valid -- Lacey Elimia
  Elimia curreyana (Lea, 1841) -- valid -- Amber Elimia
  Elimia curvicostata (Reeve, 1861) -- invalid -- graphite elimia
  Elimia cylindracea (Conrad, 1834) -- valid -- Cylinder Elimia
  Elimia dickinsoni (Clench and Turner, 1956) -- valid -- Stately Elimia
  Elimia dislocata (Reeve, 1861) -- valid -- Lapped Elimia
  Elimia ebenum (Lea, 1841) -- valid -- Ebony Elimia
  Elimia edgariana (Lea, 1841) -- valid -- Cumberland Elimia
  Elimia fascinans (Lea, 1861) -- valid -- Banded Elimia
  Elimia flava (Lea, 1862) -- valid -- Yellow Elimia
  Elimia floridensis (Reeve, 1860) -- valid -- Rasp Elimia, Waccasassa Elimia
  Elimia fusiformis (Lea, 1861) -- valid -- Fusiform Elimia
  Elimia gerhardti (Lea, 1862) -- invalid -- coldwater elimia
  Elimia gibbera (Goodrich, 1922) -- valid -- Shouldered Elimia
  Elimia haysiana (Lea, 1843) -- valid -- Silt Elimia
  Elimia hydei (Conrad, 1834) -- invalid -- gladiator elimia
  Elimia impressa (Lea, 1841) -- valid -- Constricted Elimia
  Elimia inclinans (Lea, 1862) -- valid -- Slanted Elimia
  Elimia interrupta (Haldeman, 1840) -- valid -- knotty elimia
  Elimia interveniens (Lea, 1862) -- valid -- Slowwater Elimia
  Elimia jonesi (Goodrich, 1936) -- valid -- Hearty Elimia
  Elimia lachryma (Reeve, 1861) -- valid -- Teardrop Elimia
  Elimia laeta (Jay, 1839) -- valid -- Ribbed Elimia
  Elimia laqueata (Say, 1829) -- valid -- Panel Elimia
  Elimia livescens (Menke, 1830) -- valid -- Liver Elimia
  Elimia macglameriana (Goodrich, 1936) -- valid -- Wrinkled Elimia
  Elimia mutabilis (Lea, 1862) -- valid -- Oak Elimia
  Elimia nassula (Conrad, 1834) -- valid -- round-rib elimia, Round-ribed Elimia
  Elimia olivula (Conrad, 1834) -- valid -- Caper Elimia
  Elimia ornata (Lea, 1868) -- valid -- Ornate Elimia
  Elimia paupercula (Lea, 1862) -- valid -- Sooty Elimia
  Elimia perstriata (Lea, 1852) -- valid -- Engraved Elimia
  Elimia pilsbryi (Goodrich, 1927) -- valid -- Rough-lined Elimia
  Elimia plicatastriata (Wetherby, 1876) -- valid -- Carved Elimia
  Elimia porrecta (Lea, 1863) -- valid -- Nymph Elimia
  Elimia potosiensis (Lea, 1841) -- valid -- Pyramid Elimia
  Elimia proxima (Say, 1825) -- valid -- Sprite Elimia
  Elimia pupaeformis (Lea, 1864) -- valid -- Pupa Elimia
  Elimia pupoidea (Anthony, 1854) -- valid -- Bot Elimia
  Elimia pybasi (Lea, 1862) -- invalid -- brook elimia, spring elimia
  Elimia pygmaea (H. H. Smith, 1936) -- valid -- Pygmy Elimia
  Elimia semicarinata (Say, 1829) -- valid -- Fine-ridged Elimia
  Elimia showalteri (Lea, 1861) -- invalid -- compact elimia
  Elimia simplex (Say, 1825) -- valid -- Smooth Elimia
  Elimia striatula (Lea, 1842) -- valid -- File Elimia
  Elimia strigosa (Lea, 1841) -- valid -- Brook Elimia
  Elimia symmetrica (Haldeman, 1841) -- valid -- Symmetrical Elimia
  Elimia taitiana (Lea, 1841) -- valid -- Dented Elimia
  Elimia teres (Lea, 1841) -- valid -- Elegant Elimia
  Elimia troostiana (Lea, 1838) -- valid -- Mossy Elimia
  Elimia vanhyningiana (Goodrich, 1921) -- valid -- Goblin Elimia
  Elimia vanuxemiana (Lea, 1843) -- valid -- Cobble Elimia
  Elimia varians (Lea, 1861) -- valid -- Puzzle Elimia
  Elimia variata (Lea, 1861) -- valid -- Squat Elimia
  Elimia viennaensis (Lea, 1862) -- valid -- Slough Elimia
  Elimia virginica (Say, 1817) -- invalid -- Piedmont Elimia
  Ellipsaria Rafinesque, 1820 -- valid
  Ellipsaria lineolata (Rafinesque, 1820) -- valid -- butterfly mussel
  Elliptio Rafinesque, 1819 -- valid
  Elliptio ahenea (Lea, 1845) -- valid -- southern lance
  Elliptio angustata (Lea, 1831) -- valid -- Carolina lance
  Elliptio arca (Conrad, 1834) -- valid -- Alabama spike
  Elliptio arctata (Conrad, 1834) -- valid -- delicate spike
  Elliptio buckleyi (Lea, 1843) -- invalid -- Florida shiny spike
  Elliptio chipolaensis (Walker, 1905) -- valid -- Chipola slabshell
  Elliptio complanata (Lightfoot, 1786) -- valid -- eastern elliptio
  Elliptio congaraea (Lea, 1831) -- valid -- Carolina slabshell
  Elliptio crassidens (Lamarck, 1819) -- valid -- elephant-ear, elephantear
  Elliptio cylindracea Frierson, 1927 -- invalid
  Elliptio dariensis (Lea, 1842) -- valid -- Georgia elephantear
  Elliptio dilatata (Rafinesque, 1820) -- invalid -- spike
  Elliptio downiei (Lea, 1858) -- valid -- Satilla elephantear
  Elliptio errans (Lea, 1856) -- invalid -- oval Elliptio
  Elliptio fisheriana (Lea, 1838) -- valid -- northern lance
  Elliptio folliculata (Lea, 1838) -- valid -- pod lance
  Elliptio fraterna (Lea, 1852) -- valid -- brother spike
  Elliptio hepatica (Lea, 1859) -- invalid -- brown elliptio
  Elliptio hopetonensis (Lea, 1838) -- valid -- Altamaha slabshell
  Elliptio icterina (Conrad, 1834) -- valid -- variable spike
  Elliptio jayensis (Lea, 1838) -- valid -- Florida spike, flat spike
  Elliptio judithae Clarke, 1986 -- invalid -- plicate spike
  Elliptio lanceolata (Lea, 1828) -- valid -- yellow lance
  Elliptio lugubris (Lea, 1838) -- invalid -- sad elliptio
  Elliptio macmichaeli Clench & Turner, 1956 -- invalid -- fluted elephant-ear
  Elliptio marsupiobesa Fuller, 1972 -- valid -- Cape Fear spike
  Elliptio mcmichaeli Clench & Turner, 1956 -- valid -- fluted elephantear
  Elliptio monroensis (Lea, 1843) -- valid -- St. Johns elephantear
  Elliptio nigella (Lea, 1852) -- valid -- winged spike
  Elliptio producta (Conrad, 1836) -- valid -- Atlantic spike
  Elliptio raveneli (Conrad, 1834) -- invalid -- Carolina spike
  Elliptio roanokensis (Lea, 1838) -- valid -- Roanoke slabshell
  Elliptio shepardiana (Lea, 1834) -- valid -- Altamaha lance
  Elliptio spinosa (Lea, 1836) -- valid -- Altamaha spinymussel
  Elliptio steinstansana R. I. Johnson & Clarke, 1983 -- invalid -- Tar River spinymussel, Tar spinymussel
  Elliptio waccamawensis (Lea, 1863) -- invalid -- Waccamaw spike
  Elliptio waltoni (B. H. Wright, 1888) -- invalid -- Florida lance
  Elliptoideus Frierson, 1927 -- valid
  Elliptoideus sloatianus (Lea, 1840) -- valid -- purple bankclimber
  Ellobiidae L. Pfeiffer, 1854 -- valid
  Ellobium Roding, 1798 -- valid
  Ellobium dominicense (Ferussac, 1821) -- valid -- white melampus
  Elysia canguzua Er. Marcus, 1955 -- valid
  Elysia catulus (Gould, 1870) -- valid
  Elysia chlorotica Gould, 1870 -- valid -- eastern emerald elysia, emerald elysia
  Elysia cornigera Nuttall, 1989 -- valid
  Elysia crispata Mørch, 1863 -- valid -- lettuce slug
  Elysia evelinae Er. Marcus, 1957 -- valid
  Elysia hedgpethi Er. Marcus, 1961 -- valid
  Elysia ornata (Swainson, 1840) -- valid -- ornate elysia
  Elysia papillosa A. E. Verrill, 1901 -- valid -- papillose elysia
  Elysia patina Ev. Marcus, 1980 -- valid
  Elysia serca Er. Marcus, 1955 -- valid -- caribbean seagrass elysia, seagrass elysia
  Elysia subornata A. E. Verrill, 1901 -- valid
  Elysia tuca Ev. Marcus and Er. Marcus, 1967 -- valid
  Elysiidae Forbes and Hanley, 1851 -- invalid
  Emarcusia Roller, 1972 -- valid
  Emarcusia morroensis Roller, 1972 -- valid -- orange-blotch aeolis
  Emarginula Lamarck, 1801 -- valid
  Emarginula dentigera Heilprin, 1889 -- valid -- toothed emarginula
  Emarginula nordica Perez Farfante, 1947 -- valid -- northern emarginula
  Emarginula phrixodes Dall, 1927 -- valid -- ruffled emarginula
  Emarginula pumila (A. Adams, 1852) -- valid -- pygmy emarginula
  Emarginula sicula J. E. Gray, 1825 -- valid -- dagger emarginula
  Emarginula tuberculosa Libassi, 1859 -- valid -- tuberculate emarginula
  Embletonia fuscata Gould, 1870 -- invalid
  Empleconia Dall, 1908 -- valid
  Empleconia vaginata (Dall, 1891) -- valid -- vaginate limops
  Enaeta H. Adams and A. Adams, 1853 -- valid
  Enaeta cylleniformis (G. B. Sowerby I, 1844) -- valid -- sand lyria
  Engina Gray, 1839 -- valid
  Engina corinnae Crovo, 1971 -- valid
  Engina strongi Pilsbry and Lowe, 1932 -- valid
  Engina turbinella (Kiener, 1835) -- valid -- white-spot engina
  Ennucula Iredale, 1931 -- valid
  Ennucula linki (Dall, 1916) -- valid -- Link nutclam
  Ennucula tenuis (Montagu, 1808) -- valid -- smooth nutclam
  Ensis Schumacher, 1817 -- valid
  Ensis directus Conrad, 1843 -- valid -- atlantic jackknife clam, Atlantic jackknife
  Ensis minor Dall, 1900 -- valid -- minor jackknife clam, minor jackknife
  Ensis myrae S. S. Berry, 1953 -- valid -- california jackknife clam, California jackknife
  Ensitellops Olsson and Harbison, 1953 -- valid
  Ensitellops protexta (Conrad, 1841) -- valid -- textured sportella
  Entemnotrochus Fischer, 1885 -- valid
  Entemnotrochus adansonianus (Crosse and P. Fischer, 1861) -- valid
  Enteroxenos Bonnevie, 1902 -- valid
  Enteroxenos parastichopoli (Tikasingh, 1961) -- valid
  Entocolax Voigt, 1888 -- valid
  Entocolax ludwigii Voigt, 1888 -- valid
  Entoconcha J. Muller, 1852 -- valid
  Entoconchidae Gill, 1871 -- invalid
  Entodesma Phillips, 1845 -- valid
  Entodesma beana (d'Orbigny, 1842) -- valid -- pearly entodesma
  Entodesma navicula (A. Adams and Reeve, 1850) -- valid -- rock entodesma
  Entodesma pictum (G. B. Sowerby I, 1834) -- valid -- painted entodesma, thin entodesma
  Entovalva Voeltzkow, 1890 -- valid
  Entovalva perrieri (Malard, 1903) -- valid -- perrier montacutid, leptosynapta montacutid
  Eobania P. Hesse, 1913 -- valid
  Eobania vermiculata (Muller, 1774) -- valid -- chocolate-band snail
  Epilucina Dall, 1901 -- valid
  Epilucina californica (Conrad, 1837) -- valid -- California lucine
  Epioblasma Rafinesque, 1831 -- valid
  Epioblasma arcaeformis (Lea, 1831) -- valid -- sugarspoon
  Epioblasma biemarginata (Lea, 1857) -- valid -- angled riffleshell
  Epioblasma brevidens (Lea, 1831) -- valid -- Cumberlandian combshell
  Epioblasma capsaeformis (Lea, 1834) -- valid -- oyster mussel
  Epioblasma flexuosa (Rafinesque, 1820) -- valid -- leafshell
  Epioblasma florentina (Lea, 1857) -- valid -- yellow blossom
  Epioblasma florentina curtisi (Frierson & Utterback in Utterback, 1916) -- invalid -- Curtis' pearly mussel
  Epioblasma florentina curtisii (Frierson & Utterback in Utterback, 1916) -- invalid -- Curtis' pearly mussel
  Epioblasma florentina florentina (Lea, 1857) -- invalid -- yellow blossom, yellow blossom pearly mussel
  Epioblasma florentina walkeri (Wilson & H. W. Clark, 1914) -- invalid -- tan riffleshell
  Epioblasma haysiana (Lea, 1834) -- valid -- acornshell
  Epioblasma lenior (Lea, 1842) -- valid -- narrow catspaw
  Epioblasma lewisii (Walker, 1910) -- valid -- forkshell
  Epioblasma metastriata (Conrad, 1838) -- valid -- upland combshell
  Epioblasma obliquata (Rafinesque, 1820) -- valid -- purple cat's paw pearly mussel, catspaw
  Epioblasma obliquata obliquata (Rafinesque, 1820) -- invalid -- purple cat's paw pearly mussel, catspaw
  Epioblasma obliquata perobliqua (Conrad, 1836) -- invalid -- white cat's paw pearly mussel, white catspaw
  Epioblasma othcaloogensis (Lea, 1857) -- valid -- southern acornshell
  Epioblasma penita (Conrad, 1834) -- valid -- penitent mussel, southern combshell
  Epioblasma personata (Say, 1829) -- valid -- round combshell
  Epioblasma propinqua (Lea, 1857) -- valid -- Tennessee riffleshell
  Epioblasma sampsonii (Lea, 1862) -- valid -- Wabash riffleshell
  Epioblasma stewardsonii (Lea, 1852) -- valid -- Cumberland leafshell
  Epioblasma torulosa (Rafinesque, 1820) -- valid -- tubercled blossom
  Epioblasma torulosa gubernaculum (Reeve, 1865) -- invalid -- green blossom, green-blossom pearly mussel
  Epioblasma torulosa rangiana (Lea, 1838) -- invalid -- northern riffleshell
  Epioblasma torulosa torulosa (Rafinesque, 1820) -- invalid -- tubercled blossom, tubercled blossom pearly mussel
  Epioblasma triquetra (Rafinesque, 1820) -- valid -- snuffbox
  Epioblasma turgidula (Lea, 1858) -- valid -- turgid blossom, turgid blossom pearly mussel
  Episcynia Morch, 1875 -- valid
  Episcynia devexa Keen, 1946 -- valid
  Episcynia inornata (d'Orbigny, 1842) -- valid -- fringed vitrinella
  Episiphon didymus (Watson, 1879) -- valid -- ovate tuskshell
  Episiphon sowerbyi (Guilding, 1834) -- valid -- annulate tuskshell
  Epitoniidae Berry, 1910 -- valid
  Epitonium Roding, 1798 -- valid
  Epitonium albidum (d'Orbigny, 1842) -- valid -- bladed wentletrap
  Epitonium angulatum (Say, 1830) -- valid -- angulate wentletrap
  Epitonium apiculatum (Dall, 1889) -- valid -- semismooth wentletrap
  Epitonium babylonia (Dall, 1889) -- valid -- tower wentletrap
  Epitonium blainei Clench and Turner, 1953 -- valid
  Epitonium candeanum (d'Orbigny, 1842) -- valid
  Epitonium celesti (Aradas, 1854) -- valid
  Epitonium championi Clench and Turner, 1952 -- valid
  Epitonium dallianum (A. E. Verrill and S. Smith, 1880) -- valid
  Epitonium denticulatum (G. B. Sowerby II, 1844) -- valid -- tooth-rib wentletrap
  Epitonium foliaceicosta (d'Orbigny, 1842) -- valid -- wrinkle-rib wentletrap
  Epitonium fractum Dall, 1927 -- valid -- humble wentletrap
  Epitonium frielei (Dall, 1889) -- valid
  Epitonium greenlandicum (G. Perry, 1811) -- valid -- Greenland wentletrap
  Epitonium humphreysii (Kiener, 1838) -- valid
  Epitonium krebsii (Morch, 1874) -- valid
  Epitonium lamellosum (Lamarck, 1822) -- valid -- lamellose wentletrap
  Epitonium matthewsae Clench and Turner, 1952 -- valid
  Epitonium multistriatum (Say, 1826) -- valid -- many-ribbed wentletrap
  Epitonium novangliae (Couthouy, 1838) -- valid -- New England wentletrap
  Epitonium occidentale (Nyst, 1871) -- valid -- fine-ribbed wentletrap
  Epitonium phymanthi Robertson, 1994 -- valid
  Epitonium rupicola (Kurtz, 1860) -- valid -- brown-band wentletrap
  Epitonium sericifilum (Dall, 1889) -- valid -- silky wentletrap
  Epitonium striatissimum (di Monterosato, 1878) -- valid -- frosted wentletrap
  Epitonium tollini Bartsch, 1938 -- valid
  Epitonium unifasciatum (G. B. Sowerby II, 1844) -- valid -- one-band wentletrap
  Eratoidea Weinkauff, 1879 -- valid
  Eratoidea hematita (Kiener, 1834) -- valid -- carmine marginella
  Ercolania Trinchese, 1872 -- valid
  Ercolania boodleae (Baba, 1938) -- valid
  Ercolania coerulea Trinchese, 1893 -- valid -- blue stiliger
  Ercolania funerea (A. Costa, 1867) -- valid
  Ercolania fuscata (Gould, 1870) -- valid -- dusky stiliger
  Eremarionta Pilsbry, 1913 -- valid
  Eremarionta brunnea (Willett, 1935) -- valid -- Chuckwalla Spring desertsnail
  Eremarionta immaculata (Willett, 1937) -- valid -- white desertsnail
  Eremarionta millepalmarum (S. S. Berry, 1930) -- valid -- Thousand Palms desertsnail
  Eremarionta morongoana (S. S. Berry, 1929) -- valid -- Morongo desertsnail
  Eremarionta newcombi Pilsbry and Ferriss, 1923 -- valid
  Eremarionta orocopia (Willett, 1939) -- valid -- Orocopia desertsnail
  Eremarionta rowelli (Newcomb, 1865) -- valid -- eastern desertsnail
  Eremariontoides Miller, 1981 -- valid
  Eremariontoides argus (Edson, 1912) -- valid -- Argus desertsnail
  Erginus Jeffreys, 1877 -- valid
  Erginus apicinus (Dall, 1879) -- valid -- cap limpet
  Erginus moskalevi (Golikov and Kussakin, 1972) -- valid
  Erginus puniceus Lindberg, 1988 -- valid
  Erginus rubellus (Fabricius, 1780) -- valid -- reddish limpet
  Erginus sybariticus (Dall, 1871) -- valid -- lush limpet
  Erosaria Troschel, 1863 -- valid
  Erosaria acicularis (Gmelin, 1791) -- valid -- Atlantic yellow cowrie
  Ersilia di Monterosato, 1872 -- valid
  Ersilia stancyki Waren, 1980 -- valid -- eastern brittlestar snail, brittlestar snail
  Ervilia Turton, 1822 -- valid
  Ervilia concentrica (Holmes, 1860) -- valid -- concentric ervilia
  Ervilia nitens (Montagu, 1808) -- valid -- shining ervilia
  Ervilia subcancellata E. A. Smith, 1885 -- valid -- subcancellate ervilia
  Erycina Lamarck, 1805 -- valid
  Erycina emmonsi Dall, 1899 -- valid -- emmons erycina, rectangular erycina
  Erycina linella Dall, 1899 -- valid -- lined erycina
  Erycina periscopiana Dall, 1899 -- valid -- periscope erycina
  Eubela Dall, 1889 -- valid
  Eubela limacina (Dall, 1881) -- valid
  Eubela mcgintyi Schwengel, 1943 -- valid
  Eubranchidae Odhner, 1934 -- valid
  Eubranchus Forbes, 1838 -- valid
  Eubranchus coniclus (Er. Marcus, 1958) -- valid
  Eubranchus exiguus (Alder and Hancock, 1848) -- valid -- balloon aeolis, dwarf balloon aeolis
  Eubranchus misakiensis Baba, 1960 -- valid -- Misaki balloon aeolis
  Eubranchus olivaceus (O'Donoghue, 1922) -- valid -- green balloon aeolis
  Eubranchus pallidus (Alder and Hancock, 1842) -- valid
  Eubranchus rustyus (Er. Marcus, 1961) -- valid -- rustya aeolis
  Eubranchus sanjuanensis Roller, 1972 -- valid
  Eubranchus steinbecki Behrens, 1987 -- valid
  Eubranchus tricolor Forbes, 1838 -- valid -- painted balloon aeolis
  Euchelus Philippi, 1847 -- valid
  Euchelus guttarosea Dall, 1889 -- valid -- red-spot topsnail
  Euchemotrema Archer, 1939 -- valid
  Euchemotrema fasciatum (Pilsbry, 1940) -- valid -- mountain pillsnail
  Euchemotrema fraternum (Say, 1824) -- valid -- upland pillsnail
  Euchemotrema hubrichti (Pilsbry, 1940) -- valid -- carinate pillsnail
  Euchemotrema leai (A. Binney, 1841) -- valid -- lowland pillsnail
  Euchemotrema wichitorum (Branson, 1972) -- valid -- wichita mountain pillsnail, Wichita Mountains pillsnail
  Euconulus Reinhardt, 1883 -- valid
  Euconulus chersinus (Say, 1821) -- valid -- wild hive
  Euconulus dentatus (Sterki, 1893) -- valid -- toothed hive
  Euconulus fulvus (Muller, 1774) -- valid -- brown hive
  Euconulus polygyratus (Pilsbry, 1899) -- valid -- fat hive
  Euconulus trochulus (Reinhardt, 1883) -- valid -- silk hive
  Eucrassatella Iredale, 1924 -- valid
  Eucrassatella fluctuata (Carpenter, 1864) -- valid -- wavy crassatella
  Eucrassatella speciosa (A. Adams, 1852) -- valid -- beautiful crassatella
  Eudolium Dall, 1889 -- valid
  Eudolium bairdii (A. E. Verrill and S. Smith, 1881) -- valid
  Eudolium crosseanum (di Monterosato, 1869) -- valid -- straw tun
  Euglandina P. Fischer and Crosse, 1870 -- valid
  Euglandina rosea (Ferussac, 1818) -- valid -- rosey wolfsnail, rosy wolfsnail
  Euglandina singleyana (W. G. Binney, 1892) -- valid -- striate wolfsnail
  Euglandina texasiana (Pfeiffer, 1857) -- valid -- glossy wolfsnail
  Eulima Risso, 1826 -- valid
  Eulima alaskensis (Bartsch, 1917) -- valid -- Alaska eulima
  Eulima almo (Bartsch, 1917) -- valid
  Eulima auricincta (Abbott, 1958) -- valid -- gold-stripe eulima
  Eulima bifasciata D'Orbigny, 1842 -- valid -- two-band eulima
  Eulima fulvocincta C. B. Adams, 1850 -- valid -- brown-varice eulima
  Eulima patula Dall and Simpson, 1901 -- valid -- largemouth eulima
  Eulima raymondi Rivers, 1904 -- valid -- California eulima
  Eulimastoma Bartsch, 1904 -- valid
  Eulimastoma engonium (Bush, 1885) -- valid
  Eulimastoma teres (Bush, 1885) -- valid
  Eulimastoma weberi (Morrison, 1965) -- valid
  Eulimella Gray, 1847 -- valid
  Eulimella polita (A. E. Verrill, 1872) -- valid
  Eulimella smithii (A. E. Verrill, 1880) -- valid
  Eulimidae Philippi, 1853 -- valid
  Eulimostraca Bartsch, 1917 -- valid
  Eulimostraca subcarinata (d'Orbigny, 1842) -- valid -- brown-line eulima
  Eulithidium Pilsbry, 1898 -- valid
  Eulithidium affine (C. B. Adams, 1850) -- valid -- checkered pheasant
  Eulithidium affine affine (C. B. Adams, 1850) -- valid -- checkered pheasant
  Eulithidium affine cruentum (Robertson, 1958) -- valid -- stained pheasant
  Eulithidium bellum (M. Smith, 1937) -- valid -- shouldered pheasant
  Eulithidium comptum (Gould, 1855) -- valid -- banded pheasant
  Eulithidium pterocladicum (Robertson, 1958) -- valid -- rhodophyte pheasant
  Eulithidium pulloide (Carpenter, 1864) -- valid -- sullied pheasant
  Eulithidium rubrilineatum (Strong, 1928) -- valid -- red-line pheasant
  Eulithidium substriatum (Carpenter, 1864) -- valid -- low-line pheasant
  Eulithidium thalassicola (Robertson, 1958) -- valid -- turtlegrass pheasant
  Eumetula Thiele, 1912 -- valid
  Eumetula arctica (Morch, 1857) -- valid
  Eupera Bourguignat, 1854 -- valid
  Eupera cubensis (Prime, 1865) -- valid -- mottled fingernailclam
  Eupleura H. Adams and A. Adams, 1853 -- valid
  Eupleura caudata (Say, 1822) -- valid -- thick-lip drill
  Eupleura sulcidentata Dall, 1890 -- valid -- sharp-rib drill
  Euspira heros (Say, 1822) -- valid -- northern moonsnail
  Euspira immaculata (Totten, 1835) -- valid -- immaculate moonsnail
  Euspira levicula (A. E. Verrill, 1880) -- valid -- lightweight moonsnail
  Euspira lewisii (Gould, 1847) -- valid
  Euspira nana (Møller, 1842) -- valid -- tiny moonsnail
  Euspira pallida (Broderip and G. B. Sowerby I, 1829) -- valid -- pale moonsnail
  Euspira tenuis (Récluz, 1850) -- valid -- thin moonsnail
  Euspira triseriata (Say, 1826) -- valid -- spotted moonsnail
  Euvola Dall, 1898 -- valid
  Euvola diegensis (Dall, 1898) -- valid -- San Diego scallop
  Euvola raveneli (Dall, 1898) -- valid -- round-rib scallop
  Euvola vogdesi (R. Arnold, 1906) -- valid -- concave scallop
  Euvola ziczac (Linnaeus, 1758) -- valid -- zigzag scallop
  Evalea A. Adams, 1860 -- valid
  Evalea amchitkana (Dall and Bartsch, 1909) -- valid
  Exilioidea Grant and Gale, 1931 -- valid
  Exilioidea kelseyi (Dall, 1908) -- valid
  Exilioidea rectirostris (Carpenter, 1864) -- valid
  Fabella Conrad, 1863 -- valid
  Fabella pilsbryi (Dall, 1899) -- valid -- oval sportella
  Facelina Alder and Hancock, 1855 -- valid
  Facelina bostoniensis (Couthouy, 1838) -- valid -- Boston facelina
  Facelina stearnsi Cockerell, 1901 -- valid -- scarlet-tip aeolis
  Facelinidae Bergh, 1889 -- valid
  Falcidens Salvini-Plawen, 1968 -- valid
  Falcidens hartmanae (Schwabl, 1961) -- valid -- tailed glistenworm
  Falcidens longus Scheltema, 1997 -- valid -- slender glistenworm
  Falcidens macracanthus Scheltema, 1997 -- valid -- long-spiculed glistenworm
  Falsicingula Habe, 1958 -- valid
  Falsicingula aleutica (Dall, 1887) -- valid
  Falsicingulidae Slavoshevskaya, 1975 -- valid
  Fargoa Robertson, 1978 -- valid
  Fargoa bartschi (Winkley, 1909) -- valid
  Fargoa calesi (Bartsch, 1909) -- valid
  Fargoa dianthophila (H. W. Wells and M. J. Wells, 1961) -- valid -- serpulid odostome
  Fargoa dux (Dall and Bartsch, 1906) -- valid
  Fargoa gibbosa (Bush, 1909) -- valid
  Fasciolaria Lamarck, 1799 -- valid
  Fasciolaria bullisi Lyons, 1972 -- valid -- yellow tulip
  Fasciolaria hunteria (G. Perry, 1811) -- invalid
  Fasciolaria lilium G. Fischer, 1807 -- valid -- banded tulip
  Fasciolaria lilium branhamae Rehder and Abbott, 1951 -- valid -- banded tulip
  Fasciolaria lilium bullisi Lyons, 1972 -- invalid -- yellow tulip
  Fasciolaria lilium hunteria (G. Perry, 1811) -- valid -- banded tulip
  Fasciolaria lilium lilium G. Fischer, 1807 -- valid -- banded tulip
  Fasciolaria lilium tortugana Hollister, 1957 -- valid -- banded tulip
  Fasciolaria tulipa (Linnaeus, 1758) -- valid -- true tulip
  Fasciolariidae Gray, 1853 -- valid
  Favartia Jousseaume, 1880 -- valid
  Favartia alveata (Kiener, 1842) -- valid -- frilly dwarf triton
  Favartia cellulosa (Conrad, 1846) -- valid -- pitted murex
  Favartia lindae Petuch, 1987 -- valid
  Favartia minirosea (Abbott, 1954) -- valid -- rosy drill
  Favartia pacei Petuch, 1988 -- valid
  Favartia richardbinghami (Petuch, 1987) -- valid
  Favorinus M. E. Gray, 1850 -- valid
  Favorinus auritulus Er. Marcus, 1955 -- valid
  Fedikovella Moskalev, 1976 -- valid
  Fedikovella beanii (Dall, 1882) -- valid
  Ferrissia Walker, 1903 -- valid
  Ferrissia fragilis (Tryon, 1863) -- invalid -- Fragile Ancylid
  Ferrissia hendersoni (Walker, 1908) -- invalid -- blackwater ancylid
  Ferrissia mcneili Walker, 1925 -- invalid -- hood ancylid
  Ferrissia parallelus (Haldeman, 1841) -- invalid -- Oblong Ancylid
  Ferrissia rivularis (Say, 1817) -- valid -- Creeping Ancylid
  Ferrissia walkeri (Pilsbry and Ferriss, 1907) -- invalid -- cloche ancylid
  Ferrussaciidae -- invalid
  Ficidae Conrad, 1867 -- invalid
  Ficus Röding, 1798 -- valid -- figsnails
  Ficus communis Roding, 1798 -- valid -- Atlantic figsnail
  Finella A. Adams, 1860 -- valid
  Finella adamsi (Dall, 1889) -- valid
  Finella barbarensis (Bartsch, 1911) -- valid -- Santa Barbara cerith
  Finella californica (Dall and Bartsch, 1901) -- valid -- California cerith
  Finella dubia (d'Orbigny, 1842) -- valid
  Finella hamlini (Bartsch, 1911) -- valid
  Finella io (Bartsch, 1911) -- valid
  Finella phanea (Bartsch, 1911) -- valid
  Finella tenuisculpta (Carpenter, 1864) -- valid -- fine-sculpted cerith
  Fiona Alder and Hancock, 1851 -- valid
  Fiona pinnata (Eschscholtz, 1831) -- valid -- fiona
  Fionidae Gray, 1857 -- valid
  Firoloida Lesueur, 1817 -- valid
  Firoloida demarestia Lesueur, 1817 -- valid
  Fisherola Hannibal, 1912 -- valid
  Fisherola nuttalli (Haldeman, 1841) -- valid -- Shortface Lanx
  Fissidentalium floridense (J. B. Henderson, 1920) -- valid -- yellow tuskshell
  Fissurella Bruguiere, 1789 -- valid
  Fissurella angusta (Gmelin, 1791) -- valid -- narrow keyhole limpet
  Fissurella barbadensis (Gmelin, 1791) -- valid -- Barbados keyhole limpet
  Fissurella fascicularis Lamarck, 1822 -- valid -- wobbly keyhole limpet
  Fissurella nodosa (Born, 1778) -- valid -- knobby keyhole limpet
  Fissurella punctata P. Fischer, 1857 -- valid -- punctate keyhole limpet
  Fissurella rosea (Gmelin, 1791) -- valid -- rosy keyhole limpet
  Fissurella volcano Reeve, 1849 -- valid -- volcano keyhole limpet
  Fissurellidae Fleming, 1822 -- valid
  Fissurellidea D'Orbigny, 1841 -- valid
  Fissurellidea bimaculata Dall, 1871 -- valid -- two-spot keyhole limpet
  Flabellina Voigt, 1834 -- valid
  Flabellina cooperi (Cockerell, 1901) -- valid -- blue-patch aeolis
  Flabellina engeli Ev. Marcus and Er. Marcus, 1968 -- valid
  Flabellina gracilis (Alder and Hancock, 1844) -- valid
  Flabellina iodinea (J. G. Cooper, 1863) -- invalid -- purple aeolis, Spanish shawl
  Flabellina nobilis (A. E. Verrill, 1880) -- valid
  Flabellina pellucida (Alder and Hancock, 1843) -- valid -- pellucid aeolis
  Flabellina pricei (MacFarland, 1966) -- valid -- smooth-tooth aeolis
  Flabellina salmonacea (Couthouy, 1838) -- valid -- salmon aeolis
  Flabellina subrosacea (Eschscholtz, 1831) -- valid
  Flabellina trilineata (O'Donoghue, 1921) -- valid -- threeline aeolis
  Flabellina trophina (Bergh, 1894) -- valid -- predaceous aeolis
  Flabellina verrucosa (M. Sars, 1829) -- valid -- red-finger aeolis
  Flabellinidae Dall and Simpson, 1901 -- invalid
  Floridiscrobs Pilsbry and McGinty, 1949 -- valid
  Floridiscrobs dysbatus (Pilsbry and McGinty, 1949) -- valid
  Fluminicola Stimpson, 1865 -- valid
  Fluminicola coloradoensis Morrison, 1940 -- valid -- Green River Pebblesnail
  Fluminicola dalli (Call, 1884) -- valid -- Pyramid Lake Pebblesnail
  Fluminicola fuscus (Haldeman, 1847) -- valid -- Ashy Pebblesnail
  Fluminicola minutissimus Pilsbry, 1907 -- valid -- Pixie Pebblesnail
  Fluminicola modoci Hannibal, 1912 -- valid -- Modoc Pebblesnail
  Fluminicola nuttallianus (Lea, 1838) -- valid -- Dusky Pebblesnail
  Fluminicola seminalis (Hinds, 1842) -- valid -- Nugget Pebblesnail
  Fluminicola turbiniformis (Tryon, 1865) -- valid -- Turban Pebblesnail
  Fluminicola virens (Lea, 1838) -- valid -- Olympia Pebblesnail
  Folinia Crosse, 1868 -- valid
  Folinia bermudezi (Aguayo and Rehder, 1936) -- valid
  Fontigens Pilsbry, 1933 -- valid
  Fontigens aldrichi (Call and Beecher, 1886) -- valid -- Hoosier Amnicola, Hoosier Springsnail
  Fontigens antroecetes (Hubricht, 1972) -- valid -- Missouri Cavesnail
  Fontigens binneyana (Hannibal, 1912) -- invalid
  Fontigens bottimeri (Walker, 1925) -- valid -- Potomac Springsnail
  Fontigens cryptica Hubricht, 1963 -- valid -- Hidden Springsnail
  Fontigens morrisoni Hershler, Holsinger and Hubricht, 1990 -- valid -- Morrison's Springsnail
  Fontigens nickliniana (Lea, 1838) -- valid -- Watercress Snail
  Fontigens orolibas Hubricht, 1957 -- valid -- Blue Ridge Springsnail
  Fontigens proserpina (Hubricht, 1940) -- valid -- Proserpine Cavesnail
  Fontigens tartarea Hubricht, 1963 -- valid -- Organ Cavesnail
  Fontigens turritella Hubricht, 1976 -- valid -- Greenbrier Cavesnail
  Fontigens weberi Pilsbry, 1950 -- invalid
  Forreria Jousseaume, 1880 -- valid
  Forreria belcheri (Hinds, 1843) -- valid
  Fossaria Westerlund, 1885 -- invalid
  Fossaria alberta (F. C. Baker, 1919) -- invalid
  Fossaria bulimoides (Lea, 1841) -- invalid
  Fossaria cockerelli (Pilsbry and Ferriss, 1906) -- invalid
  Fossaria cubensis (Pfeiffer, 1839) -- invalid -- Carib fossaria
  Fossaria cyclostoma (Walker, 1808) -- invalid -- bugle fossaria
  Fossaria dalli (F. C. Baker, 1907) -- invalid -- dusky fossaria
  Fossaria exigua (Lea, 1841) -- invalid
  Fossaria galbana (Say, 1825) -- invalid -- boreal fossaria
  Fossaria hendersoni (F. C. Baker, 1909) -- invalid
  Fossaria humilis (Say, 1822) -- invalid -- marsh fossaria
  Fossaria modicella (Say, 1825) -- invalid -- rock fossaria
  Fossaria obrussa (Say, 1825) -- invalid -- golden fossaria
  Fossaria parva (Lea, 1841) -- invalid -- pygmy fossaria
  Fossaria peninsulae (Walker, 1908) -- invalid
  Fossaria perplexa F. C. Baker and J. Henderson, 1929 -- invalid
  Fossaria perpolita (Dall, 1905) -- invalid -- glossy fossaria
  Fossaria rustica (Lea, 1841) -- invalid
  Fossaria sonomaensis (Hemphill in Pilsbry and Ferriss, 1906) -- invalid -- Sonoma fossaria
  Fossaria tazewelliana (Wolf, 1870) -- invalid -- Tazwell fossaria
  Fossaria techella (Haldeman, 1867) -- invalid
  Fossaria truncatula (Muller, 1774) -- invalid -- attenuate fossaria
  Fossaria vancouverensis (F. C. Baker, 1939) -- invalid
  Fossarus Philippi, 1841 -- valid
  Fossarus bellus Dall, 1889 -- valid -- beautiful fossarus
  Fossarus compactus Dall, 1889 -- valid -- compact fossarus
  Fossarus elegans A. E. Verrill and S. Smith, 1882 -- valid -- elegant fossarus
  Fossarus orbignyi P. Fischer, 1864 -- valid
  Frigidoalvania Waren, 1974 -- valid
  Frigidoalvania brychia (A. E. Verrill, 1884) -- valid
  Frigidoalvania cruenta (Odhner, 1915) -- valid
  Frigidoalvania janmayeni (Friele, 1878) -- valid -- Jan Mayen alvania
  Frigidoalvania pelagica (Stimpson, 1851) -- valid -- carinate alvania
  Fumonelix Emberton, 1991 -- valid
  Fumonelix archeri (Pilsbry, 1940) -- valid -- Ocoee covert
  Fumonelix christyi (Bland, 1860) -- valid -- glossy covert
  Fumonelix jonesiana (Archer, 1938) -- valid -- big-tooth covert
  Fumonelix orestes (Hubricht, 1975) -- valid -- engraved covert
  Fumonelix wetherbyi (Bland, 1873) -- valid -- clifty covert
  Fumonelix wheatleyi (Bland, 1860) -- valid -- cinnamon covert
  Fusconaia Simpson, 1900 -- valid
  Fusconaia askewi (Marsh, 1896) -- valid -- Texas pigtoe
  Fusconaia barnesiana (Lea, 1838) -- invalid -- Tennessee pigtoe
  Fusconaia cerina (Conrad, 1838) -- valid -- gulf pigtoe, southern pigtoe
  Fusconaia cor (Conrad, 1834) -- valid -- shiny pigtoe
  Fusconaia cuneolus (Lea, 1840) -- valid -- finerayed pigtoe, fine-rayed pigtoe
  Fusconaia ebena (Lea, 1831) -- invalid -- ebonyshell
  Fusconaia escambia Clench & Turner, 1956 -- valid -- narrow pigtoe
  Fusconaia flava (Rafinesque, 1820) -- valid -- Wabash pigtoe
  Fusconaia lananensis (Frierson, 1901) -- valid -- triangle pigtoe
  Fusconaia masoni (Conrad, 1834) -- valid -- Atlantic pigtoe
  Fusconaia ozarkensis (Call, 1887) -- valid -- Ozark pigtoe
  Fusconaia subrotunda (Lea, 1831) -- valid -- long-solid, longsolid
  Fusconaia succissa (Lea, 1852) -- invalid -- purple pigtoe
  Fusinus Rafinesque, 1815 -- valid
  Fusinus aepynotus (Dall, 1889) -- valid -- graceful spindle
  Fusinus alcimus (Dall, 1889) -- valid -- stout spindle
  Fusinus amphiurgus (Dall, 1889) -- valid -- slender spindle
  Fusinus barbarensis (Trask, 1855) -- valid -- Santa Barbara spindle
  Fusinus benthalis (Dall, 1889) -- valid -- modest spinkle, modest spindle
  Fusinus couei (Petit de la Saussaye, 1853) -- valid -- Yucatan spindle
  Fusinus eucosmius (Dall, 1889) -- valid -- apricot spindle
  Fusinus harfordii (Stearns, 1871) -- valid
  Fusinus helenae Bartsch, 1939 -- valid -- brown spindle
  Fusinus kobelti (Dall, 1877) -- valid
  Fusinus luteopictus (Dall, 1877) -- valid -- painted spindle
  Fusinus monksae Dall, 1915 -- valid
  Fusinus stegeri Lyons, 1978 -- valid -- ornamented spindle
  Fusitriton Cossmann, 1903 -- valid
  Fusitriton oregonensis (Redfield, 1848) -- valid -- Oregon triton
  Fustiaria stenoschizum (Pilsbry and Sharp, 1897) -- valid -- narrow-slit tuskshell
  Fustiariidae Steiner, 1991 -- valid
  Gadila fusiformis (Pilsbry and Sharp, 1898) -- valid -- fusiform toothshell
  Gadila hepburni (Dall, 1897) -- valid -- hepburn toothshell
  Gadila mayori (J. B. Henderson, 1920) -- valid -- mayor toothshell
  Gadilida Starobogatov, 1974 -- valid
  Gadilidae Stoliczka, 1868 -- valid
  Gadilinidae Chistikov, 1975 -- valid
  Galeommatidae Gray, 1840 -- valid
  Gari Schumacher, 1817 -- valid
  Gari californica (Conrad, 1849) -- valid -- California sunsetclam
  Gari fucata (Hinds, 1845) -- valid -- painted sunsetclam
  Gastrochaena Spengler, 1783 -- valid
  Gastrochaena hians (Gmelin, 1791) -- valid -- atlantic rocellaria, Atlantic gastrochaenid
  Gastrochaena ovata G. B. Sowerby I, 1834 -- valid -- ovate rocellaria, ovate gastrochaenid
  Gastrochaena stimpsoni Tryon, 1861 -- valid -- stimpson rocellaria, Stimpson gastrochaenid
  Gastrochaenidae Gray, 1840 -- valid
  Gastrocopta Wollaston, 1878 -- valid
  Gastrocopta abbreviata (Sterki, 1909) -- valid -- plains snaggletooth
  Gastrocopta armifera (Say, 1821) -- valid -- armed snaggletooth
  Gastrocopta ashmuni (Sterki, 1898) -- valid -- sluice snaggletooth
  Gastrocopta carnegiei (Sterki, 1916) -- valid -- Erie snaggletooth
  Gastrocopta clappi (Sterki, 1909) -- valid -- bluegrass snaggletooth
  Gastrocopta cochisensis (Pilsbry and Ferriss, 1910) -- valid -- Apache snaggletooth
  Gastrocopta contracta (Say, 1822) -- valid -- bottleneck snaggletooth
  Gastrocopta corticaria (Say, 1816) -- valid -- bark snaggletooth
  Gastrocopta cristata (Pilsbry and Vanatta, 1900) -- valid -- crested snaggletooth
  Gastrocopta dalliana (Sterki, 1898) -- valid -- shortneck snaggletooth
  Gastrocopta holzingeri (Sterki, 1889) -- valid -- lambda snaggletooth
  Gastrocopta pellucida (Pfeiffer, 1841) -- valid -- slim snaggletooth
  Gastrocopta pentodon (Say, 1822) -- valid -- comb snaggletooth
  Gastrocopta pilsbryana (Sterki, 1890) -- valid -- montane snaggletooth
  Gastrocopta procera (Gould, 1840) -- valid -- wing snaggletooth
  Gastrocopta prototypus (Pilsbry, 1899) -- valid -- Sonoran snaggletooth
  Gastrocopta quadridens Pilsbry, 1916 -- valid -- cross snaggletooth
  Gastrocopta riograndensis (Pilsbry, 1916) -- valid -- Rio Grande snaggletooth
  Gastrocopta riparia Pilsbry, 1916 -- valid -- Gulf Coast snaggletooth
  Gastrocopta ruidosensis (Cockerell, 1899) -- valid -- Ruidoso snaggletooth
  Gastrocopta rupicola (Say, 1821) -- valid -- tapered snaggletooth
  Gastrocopta servilis (Gould, 1843) -- valid -- wandering snag
  Gastrocopta similis (Sterki, 1909) -- valid -- Great Lakes snaggletooth
  Gastrocopta sterkiana Pilsbry, 1917 -- valid
  Gastrocopta tappaniana (C. B. Adams, 1842) -- valid -- white snaggletooth
  Gastrodonta Albers, 1850 -- valid
  Gastrodonta fonticula Wurtz, 1948 -- valid -- Appalachia bellytooth
  Gastrodonta interna (Say, 1822) -- valid -- brown bellytooth
  Gastropoda Cuvier, 1797 -- valid -- gastropods, slugs, snails, escargots, gastéropodes, limaces, caracol, caramujo, lesma
  Gastropteridae Swainson, 1840 -- valid
  Gastropteron Kosse, 1813 -- valid
  Gastropteron chacmol Gosliner, 1989 -- valid
  Gastropteron pacificum Bergh, 1893 -- valid -- Pacific batwing seaslug
  Gastropteron vespertilium Gosliner and Armes, 1984 -- valid -- flapping dingbat
  Gaza Watson, 1879 -- valid
  Gaza superba (Dall, 1881) -- valid -- superb gaza
  Geitodoris Bergh, 1892 -- valid
  Geitodoris complanata (A. E. Verrill, 1880) -- valid
  Geitodoris heathi (MacFarland, 1905) -- valid -- gritty doris
  Geitodoris immunda Bergh, 1894 -- valid
  Geitodoris pusae (Er. Marcus, 1955) -- valid
  Gemma Deshayes, 1853 -- valid
  Gemma gemma (Totten, 1834) -- valid -- amethyst gemclam
  Gemmula Weinkauff, 1875 -- valid
  Gemmula periscelida (Dall, 1889) -- valid -- Atlantic gem-turris
  Genitoconia Salvini-Plawen, 1967 -- valid
  Genitoconia mariensis Scheltema, 1997 -- valid
  Gerdiella Olsson and Bayer, 1972 -- valid
  Gerdiella corbicula (Dall, 1908) -- valid -- basket nutmeg
  Geukensia Van de Poel, 1959 -- valid
  Geukensia demissa (Dillwyn, 1817) -- valid -- ribbed mussel, ribbed-mussel
  Geukensia granosissima (G. B. Sowerby III, 1914) -- valid -- southern ribbed-mussel
  Gibberula Swainson, 1840 -- valid
  Gibberula lavalleeana (d'Orbigny, 1842) -- valid -- snowflake marginella
  Gibberula subtrigona (Carpenter, 1864) -- valid -- triangular marginella
  Gillia Stimpson, 1865 -- valid
  Gillia altilis (Lea, 1841) -- valid -- Buffalo Pebblesnail
  Glans Megerle von Muhlfeld, 1811 -- valid
  Glans carpenteri (Lamy, 1922) -- valid -- Carpenter carditid
  Glans dominguensis (d'Orbigny, 1842) -- valid -- Santo Domingo carditid
  Glaucidae Menke, 1828 -- invalid
  Glaucus Forster, 1777 -- valid
  Glaucus atlanticus Forster, 1777 -- valid -- blue glaucus
  Gleba Forskal, 1776 -- valid
  Gleba cordata Niebuhr, 1776 -- valid
  Glebula Conrad, 1853 -- valid
  Glebula rotundata (Lamarck, 1819) -- valid -- round pearlshell
  Gliabates Webb, 1959 -- valid
  Gliabates oregonius Webb, 1959 -- valid -- salamander slug
  Globivenus Coen, 1934 -- valid
  Globivenus callimorpha (Dall, 1902) -- valid -- lily venus
  Globivenus fordi (Yates, 1890) -- valid -- Ford venus
  Globivenus foresti (Fischer-Piette and Testud, 1967) -- valid
  Globivenus rigida (Dillwyn, 1817) -- valid -- rigid venus
  Globivenus rugatina (Heilprin, 1886) -- valid -- queen venus
  Glossocardia Stoliczka, 1870 -- valid
  Glossocardia agassizii (Dall, 1889) -- valid -- ox-heart clam
  Glossodoris Ehrenberg, 1831 -- valid
  Glossodoris sedna (Ev. Marcus and Er. Marcus, 1967) -- valid
  Glycymerididae Newton, 1922 -- invalid
  Glycymeris E. M. da Costa, 1778 -- valid
  Glycymeris americana (DeFrance, 1829) -- valid -- giant american bittersweet, giant bittersweet
  Glycymeris decussata (Linnaeus, 1758) -- valid -- decussate bittersweet
  Glycymeris keenae Willett, 1944 -- valid -- commarginal bittersweet
  Glycymeris pectinata (Gmelin, 1791) -- valid -- comb bittersweet
  Glycymeris septentrionalis (Middendorff, 1849) -- valid -- anorthern bittersweet, northern bittersweet
  Glycymeris spectralis Nicol, 1952 -- valid -- spectral bittersweet
  Glycymeris undata (Linnaeus, 1758) -- valid -- wavy bittersweet
  Glyphostoma Gabb, 1872 -- valid
  Glyphostoma adria Dall, 1919 -- valid
  Glyphostoma dentiferum Gabb, 1872 -- valid
  Glyphostoma elsae Bartsch, 1934 -- valid
  Glyphostoma gabbii Dall, 1889 -- valid
  Glyphostoma golfoyaquense Maury, 1917 -- valid
  Glyphostoma pilsbryi Schwengel, 1940 -- valid
  Glyphostomops Bartsch, 1934 -- valid
  Glyphostomops hendersoni (Bartsch, 1934) -- valid
  Glyphostomops oenoa (Bartsch, 1934) -- valid
  Glyphoturris Woodring, 1928 -- valid
  Glyphoturris diminuta (C. B. Adams, 1850) -- valid
  Glyphoturris eritima (Bush, 1885) -- valid
  Glyphoturris quadrata (Reeve, 1845) -- valid
  Glyphoturris rugirima (Dall, 1889) -- valid
  Glyphyalinia von Martens, 1892 -- valid
  Glyphyalinia carolinensis (Cockerell, 1890) -- valid -- spiral mountain glyph
  Glyphyalinia clingmani (Dall, 1890) -- valid -- fragile glyph
  Glyphyalinia cryptomphala (G. H. Clapp, 1915) -- valid -- thin glyph
  Glyphyalinia cumberlandiana (G. H. Clapp, 1919) -- valid -- hill glyph
  Glyphyalinia floridana (Morrison, 1937) -- valid -- Ocala glyph
  Glyphyalinia indentata (Say, 1823) -- valid -- carved glyph
  Glyphyalinia junaluskana (Clench and Banks, 1932) -- valid -- dark glyph
  Glyphyalinia latebricola Hubricht, 1968 -- valid -- stone glyph
  Glyphyalinia lewisiana (G. H. Clapp, 1908) -- valid -- pale glyph
  Glyphyalinia luticola Hubricht, 1966 -- valid -- furrowed glyph
  Glyphyalinia ocoae Hubricht, 1978 -- valid -- blue-gray glyph
  Glyphyalinia pecki Hubricht, 1966 -- valid -- blind glyph
  Glyphyalinia pentadelphia (Pilsbry, 1900) -- valid -- pink glyph
  Glyphyalinia picea Hubricht, 1976 -- valid -- rust glyph
  Glyphyalinia praecox (H. B. Baker, 1930) -- valid -- brilliant glyph
  Glyphyalinia raderi (Dall, 1898) -- valid -- Maryland glyph
  Glyphyalinia rhoadsi (Pilsbry, 1899) -- valid -- sculpted glyph
  Glyphyalinia rimula Hubricht, 1968 -- valid -- tongued glyph
  Glyphyalinia roemeri (Pilsbry and Ferriss, 1906) -- valid -- pretty glyph
  Glyphyalinia sculptilis (Bland, 1858) -- valid -- suborb glyph
  Glyphyalinia specus Hubricht, 1965 -- valid -- hollow glyph
  Glyphyalinia umbilicata (Cockerell, 1893) -- valid -- Texas glyph
  Glyphyalinia vanattai (Pilsbry and Walker, 1902) -- valid -- honey glyph
  Glyphyalinia virginica (Morrison, 1937) -- valid -- depressed glyph
  Glyphyalinia wheatleyi (Bland, 1883) -- valid -- bright glyph
  Glyptaesopus Pilsbry and Olsson, 1941 -- valid
  Glyptaesopus proctorae (M. Smith, 1936) -- valid
  Glyptostoma Bland and W. G. Binney, 1873 -- valid
  Glyptostoma gabrielense Pilsbry, 1938 -- valid -- San Gabriel chestnut
  Glyptostoma newberryanum (W. G. Binney, 1858) -- valid -- San Diego chestnut
  Godiva Macnae, 1954 -- valid
  Godiva rubrolineata Edmunds, 1964 -- valid
  Gonatus berryi Naef, 1923 -- valid -- Berry armhook squid
  Gonatus fabricii (Lichtenstein, 1818) -- valid -- boreoatlantic armhook squid
  Gonidea Conrad, 1857 -- valid
  Gonidea angulata (Lea, 1838) -- valid -- western ridged mussel
  Goniobasis cahawbensis Lea, 1841 -- invalid
  Goniodorididae H. Adams and A. Adams, 1854 -- valid
  Gouldia C. B. Adams, 1847 -- valid
  Gouldia cerina (C. B. Adams, 1845) -- valid -- waxy gouldclam
  Granotoma Bartsch, 1941 -- valid
  Granotoma albrechti (Krause, 1885) -- valid
  Granotoma krausei (Dall, 1886) -- valid
  Granoturris Fargo, 1953 -- valid
  Granoturris presleyi Lyons, 1972 -- valid
  Granulina Jousseaume, 1888 -- valid
  Granulina hadria (Dall, 1889) -- valid
  Granulina margaritula (Carpenter, 1857) -- valid -- pear-shaped marginella, pear marginella
  Granulina ovuliformis (d'Orbigny, 1841) -- valid -- teardrop marginella
  Graphis Jeffreys, 1867 -- valid
  Graphis underwoodae Bartsch, 1947 -- valid
  Graptacme calamus (Dall, 1889) -- valid -- reed tuskshell
  Graptacme eborea (Conrad, 1846) -- valid -- ivory tuskshell
  Graptacme inversa (Deshayes, 1826) -- valid -- turned tuskshell
  Graptacme semipolita (Broderip and G. B. Sowerby I, 1829) -- valid -- half-smooth tuskshell
  Graptacme semistriolata (Guilding, 1834) -- valid -- scratched tuskshell
  Gregariella di Monterosato, 1884 -- valid
  Gregariella chenui (Recluz, 1842) -- valid -- Chenu mussel
  Gregariella coarctata (Carpenter, 1857) -- valid -- cancellate mussel
  Gregariella coralliophaga (Gmelin, 1791) -- valid -- coral-eating mussel
  Grippina Dall, 1912 -- valid
  Grippina californica Dall, 1912 -- valid -- California grippclam
  Gryphaeidae Vyalov, 1936 -- valid
  Guppya Morch, 1867 -- valid
  Guppya gundlachi (Pfeiffer, 1839) -- valid -- glossy granule
  Guppya miamiensis Pilsbry, 1903 -- valid
  Guppya sterkii (Dall, 1888) -- valid
  Gymnobela A. E. Verrill, 1884 -- valid
  Gymnobela agassizii (A. E. Verrill and S. Smith, 1880) -- valid
  Gymnomenia Odhner, 1919 -- valid
  Gymnomenia minuta Scheltema, 1997 -- valid
  Gymnomeniidae -- valid
  Gymnosomata Blainville, 1824 -- invalid
  Gyraulus Agassiz, 1837 -- valid
  Gyraulus circumstriatus (Tryon, 1866) -- valid -- Disc Gyro
  Gyraulus crista (Linnaeus, 1758) -- valid -- Star Gyro
  Gyraulus deflectus (Say, 1824) -- valid -- Flexed Gyro
  Gyraulus hornensis F. C. Baker, 1934 -- valid -- Tuba Gyro
  Gyraulus parvus (Say, 1817) -- valid -- Ash Gyro
  Gyrotoma Shuttleworth, 1845 -- valid
  Gyrotoma excisa (Lea, 1843) -- valid -- Excised Slitshell
  Gyrotoma lewisii (Lea, 1869) -- valid -- Striate Slitshell
  Gyrotoma pagoda (Lea, 1845) -- valid -- Pagoda Slitshell
  Gyrotoma pumila (Lea, 1860) -- valid -- Ribbed Slitshell
  Gyrotoma pyramidata (Shuttleworth, 1845) -- valid -- Pyramid Slitshell
  Gyrotoma walkeri (H. H. Smith, 1924) -- valid -- Round Slitshell
  Habevolutopsius attenuatus (Dall, 1874) -- valid -- elongate whelk
  Halicardia Dall, 1895 -- valid
  Halicardia flexuosa (A. E. Verrill and S. Smith, 1881) -- valid -- flexed verticord
  Haliotididae Rafinesque, 1815 -- invalid
  Haliotinella Souverbie, 1875 -- valid
  Haliotinella patinaria (Guppy, 1876) -- valid -- fingernail moonsnail
  Haliotis Linnaeus, 1758 -- valid -- abalone
  Haliotis assimilis Dall, 1878 -- invalid -- threaded abalone
  Haliotis corrugata W. Wood, 1828 -- valid -- pink abalone, abulón amarillo
  Haliotis cracherodii Leach, 1814 -- valid -- black abalone, abulón negro
  Haliotis fulgens Philippi, 1845 -- valid -- green abalone, abulón azul
  Haliotis kamtschatkana Jonas, 1845 -- valid -- pinto abalone
  Haliotis pourtalesii Dall, 1881 -- valid
  Haliotis rufescens Swainson, 1822 -- valid -- red abalone, abulón rojo
  Haliotis sorenseni Bartsch, 1940 -- valid -- white abalone
  Haliotis walallensis Stearns, 1899 -- valid -- flat abalone, northern green abalone
  Haliris Dall, 1886 -- valid
  Haliris aequacostata (Howard, 1950) -- valid -- even-ribbed verticord
  Haliris fischeriana (Dall, 1881) -- valid -- beaded verticord
  Halistrepta Dall, 1904 -- valid
  Halistrepta sulcata (Dall, 1904) -- valid -- sulcate spoonclam
  Halistylus Dall, 1890 -- valid
  Halistylus pupoideus (Carpenter, 1864) -- valid -- pupa halistyle
  Hallaxa Eliot, 1909 -- valid
  Hallaxa chani Gosliner and Williams, 1975 -- valid
  Haloceras Dall, 1889 -- valid
  Haloceras trichotropoides Waren and Bouchet, 1991 -- valid
  Haloceratidae Warén and Bouchet, 1991 -- valid
  Haloconcha Dall, 1886 -- valid
  Haloconcha minor Dall, 1919 -- valid -- lesser lacuna
  Haloconcha refleza (Dall, 1884) -- valid -- reflexed lacuna
  Halodakra Olsson, 1961 -- valid
  Halodakra salmonea (Carpenter, 1864) -- valid -- salmon bernard-clam, salmon bernardclam
  Halodakra subtrigona (Carpenter, 1857) -- valid -- subtrigonal bernard-clam, subtrigonal bernardclam
  Haminoea Turton and Kingston, 1830 -- valid
  Haminoea antillarum (d'Orbigny, 1841) -- valid -- Antilles glassy-bubble
  Haminoea callidegenita Gibson and Chia, 1989 -- valid
  Haminoea elegans (J. E. Gray, 1825) -- valid -- elegant glassy-bubble
  Haminoea petitii (d'Orbigny, 1841) -- valid -- straight glassy-bubble
  Haminoea solitaria (Say, 1822) -- valid -- solitary glassy-bubble
  Haminoea succinea (Conrad, 1846) -- valid -- amber glassy-bubble
  Haminoea taylorae Petuch, 1987 -- valid
  Haminoea vesicula (Gould, 1855) -- valid -- blister glassy-bubble
  Haminoea virescens (G. B. Sowerby II, 1833) -- valid -- green glassy-bubble
  Haminoeidae Pilsbry, 1895 -- valid
  Hancockia Gosse, 1877 -- valid
  Hancockia californica MacFarland, 1923 -- valid
  Hancockiidae MacFarland, 1923 -- valid
  Hanleya Gray, 1857 -- valid
  Hanleya hanleyi (Bean, 1844) -- valid -- eastern hanleya
  Hanleya nagelfar (Loven, 1842) -- valid
  Hanleyella Sirenko, 1973 -- valid
  Hanleyella asiatica Sirenko, 1973 -- valid
  Hanleyella oldroydi (Dall, 1919) -- valid
  Hanleyidae Bergenhayn, 1955 -- valid
  Haplocochlias Carpenter, 1864 -- valid
  Haplocochlias swifti Vanatta, 1913 -- valid
  Haplotrema Ancey, 1881 -- valid
  Haplotrema alameda Pilsbry, 1930 -- valid -- Alameda lancetooth
  Haplotrema caelatum (Mazyck, 1886) -- valid -- slotted lancetooth
  Haplotrema catalinense (Hemphill, 1890) -- valid -- Catalina lancetooth
  Haplotrema concavum (Say, 1821) -- valid -- gray-footed lancetooth, gray-foot lancetooth
  Haplotrema costatum A. G. Smith, 1957 -- valid -- costate lancetooth
  Haplotrema duranti (Newcomb, 1864) -- valid -- ribbed lancetooth
  Haplotrema keepi (Hemphill, 1890) -- valid -- glassy lancetooth
  Haplotrema kendeighi Webb, 1951 -- valid -- blue-footed lancetooth, blue-foot lancetooth
  Haplotrema minimum (Ancey, 1888) -- valid -- California lancetooth
  Haplotrema mokelumnense Roth, 1990 -- valid -- Mokelumne lancetooth
  Haplotrema transfuga (Hemphill, 1892) -- valid -- striate lancetooth
  Haplotrema vancouverense (I. Lea, 1839) -- valid -- robust lancetooth
  Haplotrematidae H. B. Baker, 1925 -- valid
  Harpidae Bronn, 1849 -- valid
  Hastula H. Adams and A. Adams, 1853 -- valid
  Hastula cinerea (Born, 1778) -- valid -- gray auger
  Hastula hastata (Gmelin, 1791) -- valid -- shiny auger
  Hastula maryleeae R. D. Burch, 1965 -- valid
  Hastula salleana (Deshayes, 1859) -- valid
  Haustellum Schumacher, 1817 -- valid
  Haustellum anniae (M. Smith, 1940) -- valid
  Haustellum bellegladeense (Vokes, 1963) -- valid -- Belleglade murex
  Haustellum cabritii (Bernardi, 1859) -- valid
  Haustellum rubidum (F. C. Baker, 1897) -- valid -- rose murex
  Haustellum tryoni (Hidalgo in Tryon, 1880) -- valid
  Hawaiia Gude, 1911 -- valid
  Hawaiia alachuana (Dall, 1885) -- valid -- southeastern gem
  Hawaiia minuscula (A. Binney, 1841) -- valid -- minute gem
  Hawaiia neomexicana (Cockerell and Pilsbry, 1900) -- valid -- striate gem
  Hebetoncylus Pilsbry, 1914 -- invalid
  Hebetoncylus excentricus (Morelet, 1851) -- invalid -- Excentric Ancylid
  Hedylopsis Thiele, 1931 -- valid
  Hedylopsis riseri M. P. Morse, 1976 -- valid
  Heilprinia Grabau, 1904 -- valid
  Heilprinia lindae Petuch, 1987 -- valid
  Heilprinia timessa (Dall, 1889) -- valid -- turnip spindle
  Heleobops F. G. Thompson, 1968 -- valid
  Heleobops carrikeri Davis and McKee, 1989 -- valid
  Heleobops docimus F. G. Thompson, 1968 -- valid -- Oolite Hydrobe
  Heliacus D'Orbigny, 1842 -- valid
  Heliacus alleryi (Seguenza, 1876) -- invalid
  Heliacus architae (O. G. Costa, 1841) -- invalid -- noduled sundial
  Heliacus bisulcatus (d'Orbigny, 1842) -- valid -- beaded sundial
  Heliacus borealis (A. E. Verrill and S. Smith, 1880) -- invalid -- boreal sundial
  Heliacus cylindricus (Gmelin, 1791) -- valid -- Atlantic cylinder sundial
  Heliacus infundibuliformis (Gmelin, 1791) -- valid -- channeled sundial
  Heliacus infundibuliformis perrieri (Rochebrune, 1881) -- valid -- channeled sundial
  Heliacus perrieri (Rochebrune, 1881) -- invalid -- channeled sundial
  Helicarionidae Bourguignat, 1877 -- valid
  Helicella Férussac, 1821 -- valid
  Helicella obvia (Menke, 1828) -- valid -- heath helicellid
  Helicidae Rafinesque, 1815 -- valid
  Helicina Lamarck, 1799 -- valid
  Helicina clappi Pilsbry, 1909 -- valid -- rainbow drop
  Helicinidae Latreille, 1825 -- invalid
  Helicodiscidae H. B. Baker, 1927 -- valid
  Helicodiscus E. S. Morse, 1864 -- valid
  Helicodiscus aldrichianus (G. H. Clapp, 1907) -- valid -- burrowing coil
  Helicodiscus barri Hubricht, 1962 -- valid -- raccoon coil
  Helicodiscus bonamicus Hubricht, 1978 -- valid -- spiral coil
  Helicodiscus diadema Grimm, 1967 -- valid -- shaggy coil
  Helicodiscus eigenmanni Pilsbry, 1900 -- valid -- Mexican coil
  Helicodiscus enneodon Hubricht, 1967 -- valid -- bluff coil
  Helicodiscus fimbriatus Wetherby, 1881 -- valid -- fringed coil
  Helicodiscus hadenoecus Hubricht, 1962 -- valid -- cricket coil
  Helicodiscus hexodon Hubricht, 1966 -- valid -- toothy coil
  Helicodiscus inermis H. B. Baker, 1929 -- valid -- oldfield coil
  Helicodiscus lirellus Hubricht, 1975 -- valid -- rubble coil
  Helicodiscus multidens Hubricht, 1962 -- valid -- twilight coil
  Helicodiscus notius Hubricht, 1962 -- valid -- tight coil
  Helicodiscus nummus (Vanatta, 1899) -- valid -- wax coil
  Helicodiscus parallelus (Say, 1817) -- valid -- compound coil
  Helicodiscus punctatellus Morrison, 1942 -- valid -- punctate coil
  Helicodiscus salmonaceus Hemphill, 1890 -- valid -- salmon coil
  Helicodiscus saludensis (Morrison, 1937) -- valid -- corncob snail
  Helicodiscus shimeki Hubricht, 1962 -- valid -- temperate coil
  Helicodiscus singleyanus (Pilsbry, 1889) -- valid -- smooth coil
  Helicodiscus tridens (Morrison, 1935) -- valid -- crosstimbers coil
  Helicodiscus triodus Hubricht, 1958 -- valid -- tallus coil, talus coil
  Helisoma Swainson, 1840 -- valid
  Helisoma anceps (Menke, 1830) -- valid -- Two-ridge Ramshorn
  Helisoma newberryi (Lea, 1858) -- valid -- Great Basin Ramshorn
  Helix Linnaeus, 1758 -- valid
  Helix aperta Born, 1778 -- valid -- green gardensnail
  Helix aspersa Muller, 1774 -- valid -- brown gardensnail
  Helix pomatia Linnaeus, 1758 -- valid -- escargot
  Helminthoglypta Ancey, 1887 -- valid
  Helminthoglypta allyniana (S. S. Berry, 1920) -- valid -- Sierra shoulderband
  Helminthoglypta allynsmithi Pilsbry, 1939 -- valid -- Merced Canyon shoulderband
  Helminthoglypta arrosa (W. G. Binney, 1858) -- valid -- bronze shoulderband
  Helminthoglypta avus (Bartsch, 1916) -- valid -- badger shoulderband
  Helminthoglypta ayresiana (Newcomb, 1861) -- valid -- San Miguel shoulderband
  Helminthoglypta benitoensis Lowe, 1930 -- valid -- Pinnacles shoulderband
  Helminthoglypta berryi Hanna, 1929 -- valid -- Tehachapi shoulderband
  Helminthoglypta californiensis (I. Lea, 1838) -- valid -- Point Pinos shoulderband
  Helminthoglypta callistoderma Pilsbry, 1917 -- valid -- Kern shoulderband
  Helminthoglypta carpenteri (Newcomb, 1861) -- valid -- san juaquin shoulderband, San Joaquin shoulderband
  Helminthoglypta caruthersi Willett, 1934 -- valid -- Morris Canyon shoulderband
  Helminthoglypta coelata (Bartsch, 1916) -- valid -- mesa shoulderband
  Helminthoglypta concolor Roth and Hochberg, 1988 -- valid -- whitefir shoulderband
  Helminthoglypta contracostae (Pilsbry, 1895) -- valid -- contracosta shoulderband
  Helminthoglypta crotalina S. S. Berry, 1928 -- valid -- sidewinder shoulderband
  Helminthoglypta cuyama Hanna and A. G. Smith, 1937 -- valid -- Cuyama shoulderband
  Helminthoglypta cypreophila (W. G. Binney and Bland, 1869) -- valid -- foothill shoulderband
  Helminthoglypta diabloensis (J. G. Cooper, 1869) -- valid -- silky shoulderband
  Helminthoglypta dupetithouarsii (Deshayes, 1840) -- valid -- cypress shoulderband
  Helminthoglypta edwardsi Gregg and W. B. Miller, 1976 -- valid -- Pine Valley shoulderband
  Helminthoglypta euomphalodes S. S. Berry, 1938 -- valid -- Greenhorn shoulderband
  Helminthoglypta exarata (Pfeiffer, 1857) -- valid -- santa cruz shoulderband, San Lorenzo shoulderband
  Helminthoglypta expansilabris (Pilsbry, 1898) -- valid -- Mendocino shoulderband
  Helminthoglypta fairbanksi Reeder and W. B. Miller, 1986 -- valid -- DeLuz shoulderband
  Helminthoglypta ferrissi Pilsbry, 1924 -- valid -- Kings shoulderband
  Helminthoglypta fieldi Pilsbry, 1930 -- valid -- surf shoulderband
  Helminthoglypta fisheri (Bartsch, 1904) -- valid -- Panamint shoulderband
  Helminthoglypta fontiphila Gregg, 1931 -- valid -- Soledad shoulderband
  Helminthoglypta graniticola S. S. Berry, 1926 -- valid -- granite shoulderband
  Helminthoglypta greggi Willett, 1931 -- valid -- mohave shoulderband, Mojave shoulderband
  Helminthoglypta hertleini Hanna and A. G. Smith, 1937 -- valid -- Oregon shoulderband
  Helminthoglypta inglesi S. S. Berry, 1938 -- valid -- horse meadows shoulderband, Sunday shoulderband
  Helminthoglypta isabella S. S. Berry, 1938 -- valid -- tyucca shoulderband, yucca shoulderband
  Helminthoglypta jaegeri S. S. Berry, 1928 -- valid -- Sweetwater shoulderband
  Helminthoglypta liodoma S. S. Berry, 1938 -- valid -- Cottonwood shoulderband
  Helminthoglypta mailliardi Pilsbry, 1927 -- valid -- Del Norte shoulderband
  Helminthoglypta micrometalleoides W. B. Miller, 1970 -- valid -- mimic shoulderband
  Helminthoglypta milleri Reeder, 1986 -- valid -- peak shoulderband
  Helminthoglypta mohaveana S. S. Berry, 1927 -- valid -- Victorville shoulderband
  Helminthoglypta montezuma Reeder and W. B. Miller, 1986 -- valid -- Montezuma shoulderband
  Helminthoglypta napaea S. S. Berry, 1938 -- valid -- bigtree shoulderband
  Helminthoglypta nickliniana (I. Lea, 1838) -- valid -- Coast Range shoulderband
  Helminthoglypta orina S. S. Berry, 1938 -- valid -- Breckenridge shoulderband
  Helminthoglypta petricola (S. S. Berry, 1916) -- valid -- Transverse Range shoulderband
  Helminthoglypta phlyctaena (Bartsch, 1916) -- valid -- Zaca shoulderband
  Helminthoglypta piutensis Willett, 1938 -- valid -- Saddle shoulderband
  Helminthoglypta proles (Hemphill, 1892) -- valid -- Yosemite shoulderband
  Helminthoglypta reediana Willett, 1932 -- valid -- Lowe Canyon shoulderband
  Helminthoglypta salviae Roth, 1987 -- valid -- sage shoulderband
  Helminthoglypta sanctaecrucis Pilsbry, 1927 -- valid -- Limu shoulderband
  Helminthoglypta sequoicola (J. G. Cooper, 1866) -- valid -- redwood shoulderband
  Helminthoglypta similans Hanna and A. G. Smith, 1937 -- valid -- Coalinga shoulderband
  Helminthoglypta sonoma Pilsbry, 1937 -- valid -- Sonoma shoulderband
  Helminthoglypta stageri Willett, 1938 -- valid -- paiute shoulderband, Erskine Creek shoulderband
  Helminthoglypta stiversiana (J. G. Cooper, 1876) -- valid -- Point Reyes shoulderband
  Helminthoglypta talmadgei Roth, 1988 -- valid -- Trinity shoulderband
  Helminthoglypta taylori Reeder and Roth, 1988 -- valid -- West Fork shoulderband
  Helminthoglypta tejonis S. S. Berry, 1930 -- valid -- Tejon shoulderband
  Helminthoglypta thermimontis S. S. Berry, 1953 -- valid -- coyote shoulderband, Anza shoulderband
  Helminthoglypta traskii (Newcomb, 1861) -- valid -- peninsular range shoulderband
  Helminthoglypta tudiculata (A. Binney, 1843) -- valid -- southern california shoulderband, southern shoulderband
  Helminthoglypta tularensis (Hemphill, 1892) -- valid -- Tulare shoulderband
  Helminthoglypta umbilicata (Pilsbry, 1898) -- valid -- Big Sur shoulderband
  Helminthoglypta uvasana Roth and Hochberg, 1992 -- valid -- grapevine shoulderband
  Helminthoglypta vasquezi Roth and Hochberg, 1992 -- valid -- Vasquez shoulderband
  Helminthoglypta venturensis (Bartsch, 1916) -- valid
  Helminthoglypta walkeriana (Hemphill, 1911) -- valid -- Morro shoulderband
  Helminthoglypta waltoni Gregg and W. B. Miller, 1976 -- valid -- Laguna shoulderband
  Helminthoglypta willetti (S. S. Berry, 1920) -- valid -- Matilija shoulderband
  Helminthoglyptidae Pilsbry, 1939 -- invalid
  Helminthope Salvini-Plawen, 1991 -- valid
  Helminthope psammobionta Salvini-Plawen, 1991 -- valid
  Hemistena Rafinesque, 1820 -- valid
  Hemistena lata (Rafinesque, 1820) -- valid -- cracking pearlymussel, cracking pearly mussel
  Hemitoma Swainson, 1840 -- valid
  Hemitoma emarginata (de Blainville, 1825) -- valid -- emarginate emarginula
  Hemitoma octoradiata (Gmelin, 1791) -- valid -- eight-rib emarginula
  Hemitrochus Swainson, 1840 -- valid
  Hemitrochus varians (Menke, 1829) -- valid -- seagrape snail
  Hemphillia Bland and W. G. Binney, 1872 -- valid
  Hemphillia burringtoni Pilsbry, 1948 -- valid -- keeled jumping slug, keeled jumping-slug
  Hemphillia camelus Pilsbry and Vanatta, 1897 -- valid -- pale jumping slug, pale jumping-slug
  Hemphillia danielsi Vanatta, 1914 -- valid -- marbled jumping slug, marbled jumping-slug
  Hemphillia dromedarius Branson, 1972 -- valid -- dromedary jumping slug, dromedary jumping-slug
  Hemphillia glandulosa Bland and W. G. Binney, 1872 -- valid -- warty jumping slug, warty jumping-slug
  Hemphillia malonei Pilsbry, 1917 -- valid -- malone jumping slug, Malone jumping-slug
  Hemphillia pantherina Branson, 1975 -- valid -- panther jumping slug, panther jumping-slug
  Hendersonia Dall, 1905 -- invalid
  Hendersonia occulta (Say, 1831) -- valid -- cherrystone drop
  Henrya Bartsch, 1927 -- valid
  Henrya goldmani (Bartsch, 1947) -- valid
  Henrya morrisoni Bartsch, 1947 -- valid
  Here Gabb, 1866 -- valid
  Here excavata (Carpenter, 1857) -- valid -- pit lucine
  Hermaea Lovén, 1844 -- valid
  Hermaea cruciata Gould, 1870 -- valid
  Hermaea dendritica (Alder and Hancock, 1843) -- valid -- spanish tenor
  Hermaea kingstoni (T. E. Thompson, 1977) -- valid
  Hermaea vancouverensis O'Donoghue, 1924 -- valid
  Hermaea verticilata (Ortea, 1984) -- valid
  Hermissenda Bergh, 1879 -- valid
  Hermissenda crassicornis (Eschscholtz, 1831) -- valid -- hermissenda
  Herpeteros Berry, 1947 -- valid
  Herpeteros angelus (Gregg, 1949) -- valid -- Soledad desertsnail
  Hesperarion Simroth, 1891 -- valid
  Hesperarion hemphilli (W. G. Binney, 1875) -- valid -- hemphill western slug, Hemphill westernslug
  Hesperarion mariae Branson, 1991 -- valid -- Tillamook westernslug
  Hesperarion niger (J. G. Cooper, 1872) -- valid -- black western slug, black westernslug
  Hespererato Schilder, 1932 -- valid
  Hespererato columbella (Menke, 1847) -- valid -- pigeon erato
  Hespererato maugeriae (J. E. Gray, 1832) -- valid -- green erato
  Hespererato vitellina (Hinds, 1844) -- valid -- appleseed erato
  Heterodonax Morch, 1853 -- valid
  Heterodonax bimaculatus (Linnaeus, 1758) -- valid -- false beanclam, false-bean
  Heterodonax pacificus (Conrad, 1837) -- valid -- pacific false beanclam, Pacific false-bean
  Heterostropha -- invalid
  Hexaplex Perry, 1811 -- valid
  Hexaplex fulvescens (G. B. Sowerby II, 1834) -- valid -- giant eastern murex
  Hiatella Bosc, 1801 -- valid
  Hiatella arctica (Linnaeus, 1767) -- valid -- Arctic hiatella
  Hiatella azaria (Dall, 1881) -- valid -- dirt hiatella
  Hiatella pholadis (Linnaeus, 1771) -- valid -- hole-hugger hiatella
  Hiatella striata Fleuriau, 1802 -- valid -- striate hiatella
  Hiatellidae Gray, 1824 -- valid
  Hindsiclava Hertlein and Strong, 1955 -- valid
  Hindsiclava alesidota (Dall, 1889) -- valid
  Hindsiclava macilenta (Dall, 1889) -- valid
  Hinea Gray, 1847 -- valid
  Hinea lineata (E. M. da Costa, 1778) -- valid -- dwarf planaxis
  Hipponicidae Troschel, 1861 -- valid
  Hipponix DeFrance, 1819 -- valid
  Hipponix antiquatus (Linnaeus, 1767) -- valid -- white hoofsnail
  Hipponix subrufus (Lamarck, 1819) -- valid -- orange hoofsnail
  Hipponix tumens Carpenter, 1864 -- valid -- ribbed hoofsnail
  Hochbergellus Roth and W. B. Miller, 1992 -- valid
  Hochbergellus hirsutus Roth and W. B. Miller, 1992 -- valid -- Sisters hesperian
  Hojeda H. B. Baker, 1926 -- valid
  Hojeda inaguensis (Weinland, 1880) -- valid -- Keys mudcloak
  Holospira Martens, 1860 -- valid
  Holospira arizonensis Stearns, 1890 -- valid -- Arizona holospira
  Holospira bilamellata Dall, 1895 -- valid -- bilamellate holospira
  Holospira campestris Pilsbry and Ferriss, 1915 -- valid
  Holospira chiricahuana Pilsbry, 1905 -- valid -- Cave Creek holospira
  Holospira cionella Pilsbry, 1905 -- valid
  Holospira cockerelli Dall, 1897 -- valid -- Cockerell holospira
  Holospira crossei Dall, 1895 -- valid -- Cross holospira
  Holospira danielsi Pilsbry and Ferriss, 1915 -- valid -- strongrib holospira
  Holospira ferrissi Pilsbry, 1905 -- valid -- stocky holospira
  Holospira goldfussi (Menke, 1847) -- valid -- New Braunfels holospira
  Holospira hamiltoni Dall, 1897 -- valid -- Hamilton holospira
  Holospira mesolia Pilsbry, 1912 -- valid -- widemouth holospira
  Holospira metcalfi F. G. Thompson, 1974 -- valid -- Metcalf holospira
  Holospira millestriata Pilsbry and Ferriss, 1915 -- valid
  Holospira montivaga Pilsbry, 1946 -- valid -- vagabond holospira
  Holospira oritis Pilsbry and Cheatum, 1951 -- valid -- mountain holospira
  Holospira pasonis Dall, 1895 -- valid -- robust holospira
  Holospira pityis Pilsbry and Cheatum, 1951 -- valid -- pinecone holospira
  Holospira regis Pilsbry and Cockerell, 1905 -- valid -- royal holospira
  Holospira riograndensis Pilsbry, 1946 -- valid -- Rio Grande holospira
  Holospira sherbrookei Gilbertson, 1989 -- valid -- Silver Creek holospira
  Holospira tantalus Bartsch, 1906 -- valid -- teasing holospira
  Holospira whetstonensis Pilsbry and Ferriss, 1923 -- valid -- Whetstone holospira
  Holospira yucatanensis Bartsch, 1906 -- valid -- Bartsch holospira
  Holsingeria Hershler, 1989 -- valid
  Holsingeria unthanksensis Hershler, 1989 -- valid -- Thankless Ghostsnail
  Homalopoma Carpenter, 1864 -- valid
  Homalopoma albidum (Dall, 1881) -- valid -- white dwarf-turban
  Homalopoma baculum (Carpenter, 1864) -- valid -- berry dwarf-turban
  Homalopoma berryi J. H. McLean, 1964 -- valid
  Homalopoma cordellensis J. H. McLean, 1996 -- valid
  Homalopoma draperi J. H. McLean, 1984 -- valid
  Homalopoma grippi (Dall, 1911) -- valid
  Homalopoma indutum (Watson, 1879) -- valid -- two-faced dwarf-turban
  Homalopoma lacunatum (Carpenter, 1864) -- valid
  Homalopoma luridum (Dall, 1885) -- valid -- dark dwarf-turban
  Homalopoma mimicum LaFollette, 1976 -- valid
  Homalopoma paucicostatum (Dall, 1871) -- valid -- few-ribbed dwarf-turban, few-rib dwarf-turban
  Homalopoma radiatum (Dall, 1918) -- valid -- rayed dwarf-turban
  Homalopoma subobsoletum Willett, 1937 -- valid
  Hopkinsia MacFarland, 1905 -- valid
  Hopkinsia rosacea MacFarland, 1905 -- valid -- Hopkins rose
  Horologica Laseron, 1956 -- valid
  Horologica pupa (Dall and Simpson, 1901) -- valid
  Houbricka Wise, 1996 -- valid
  Houbricka incisa (Bush, 1899) -- valid
  Hoyia F. C. Baker, 1926 -- valid
  Hoyia sheldoni (Pilsbry, 1890) -- valid -- storm hydrobe, Storm Ghostsnail
  Humboldtiana Ihering, 1892 -- valid
  Humboldtiana agavophila Pratt, 1971 -- valid -- agave threeband
  Humboldtiana cheatumi Pilsbry, 1935 -- valid -- Davis Mountain threeband
  Humboldtiana chisosensis Pilsbry, 1927 -- valid -- Chisos threeband
  Humboldtiana edithae Parodiz, 1954 -- valid -- boulder slide threeband
  Humboldtiana ferrissiana Pilsbry, 1928 -- valid -- Mitre Peak threeband
  Humboldtiana fullingtoni Cheatum, 1972 -- valid -- Capote threeband
  Humboldtiana hoegiana (von Martens, 1892) -- valid -- San Carlos threeband
  Humboldtiana hoegiana praesidii Pilsbry, 1939 -- valid -- San Carlos threeband
  Humboldtiana palmeri Clench and Rehder, 1930 -- valid -- Mt. Livermore threeband
  Humboldtiana texana Pilsbry, 1927 -- valid -- Stockton Plateau threeband
  Humboldtiana ultima Pilsbry, 1927 -- valid -- northern threeband
  Humboldtianidae Pilsbry, 1939 -- invalid
  Humilaria Grant and Gale, 1931 -- valid
  Humilaria kennerleyi (Reeve, 1863) -- valid -- Kennerley's venus, Kennerley venus
  Huttonella L. Pfeiffer, 1856 -- valid
  Huttonella bicolor (Hutton, 1834) -- valid -- two-tone gulella
  Huxleyia A. Adams, 1860 -- valid
  Huxleyia munita (Dall, 1898) -- valid -- minute nucinellid
  Hyalina Schumacher, 1817 -- valid
  Hyalina cineracea (Dall, 1889) -- valid
  Hyalina pallida (Linnaeus, 1758) -- valid -- pallid marginella
  Hyalocylis de Folin, 1875 -- valid
  Hyalocylis striata (Rang, 1828) -- valid -- striate clio
  Hydatina Schumacher, 1817 -- valid
  Hydatina physis (Linnaeus, 1758) -- valid -- brown-line paper-bubble, brown-line paperbubble
  Hydrobia Hartmann, 1821 -- valid
  Hydrobia booneae Morrison, 1973 -- invalid -- Boone Hydrobe
  Hydrobia truncata (Vanatta, 1924) -- invalid
  Hydrobiidae Stimpson, 1865 -- valid
  Hydromyles globulosus (Rang, 1825) -- valid
  Hydromylidae Pruvot-Fol, 1942 -- valid
  Hygromiidae Tryon, 1866 -- valid
  Hypermastus Pilsbry, 1899 -- valid
  Hypermastus randolphi (Vanatta, 1900) -- valid
  Hypselodoris Stimpson, 1855 -- valid
  Hypselodoris bayeri (Ev. Marcus and Er. Marcus, 1967) -- valid
  Hypselodoris californiensis (Bergh, 1879) -- valid -- California blue doris
  Hypselodoris sycilla (Bergh, 1890) -- valid
  Hypselodoris webbi (d'Orbigny, 1839) -- valid -- Florida regal doris
  Ilyanassa Stimpson, 1865 -- invalid
  Ilyanassa obsoleta (Say, 1822) -- invalid -- eastern mudsnail
  Ilyanassa trivittata (Say, 1822) -- invalid -- three-line mudsnail
  Inflectarius Pilsbry, 1940 -- valid
  Inflectarius approximans (G. H. Clapp, 1905) -- valid -- tight-gapped shagreen
  Inflectarius downieanus (Bland, 1861) -- valid -- dwarf globelet
  Inflectarius edentatus (Sampson, 1889) -- valid -- smooth-lip shagreen
  Inflectarius ferrissi (Pilsbry, 1897) -- valid -- Smoky Mountain covert
  Inflectarius inflectus (Say, 1821) -- valid -- shagreen
  Inflectarius kalmianus (Hubricht, 1965) -- valid -- brown globelet
  Inflectarius magazinensis (Pilsbry and Ferriss, 1907) -- valid -- Magazine Mountain shagreen
  Inflectarius rugeli (Shuttleworth, 1852) -- valid -- deep-tooth shagreen
  Inflectarius smithi (G. H. Clapp, 1905) -- valid -- Alabama shagreen
  Inflectarius subpalliatus (Pilsbry, 1893) -- valid -- velvet covert
  Inflectarius verus (Hubricht, 1954) -- valid
  Iniforis Jousseaume, 1884 -- valid
  Iniforis turristhomae (Holten, 1802) -- valid -- St. Thomas triphora
  Inodrillia Bartsch, 1943 -- valid
  Inodrillia acova Bartsch, 1943 -- valid
  Inodrillia aepynota (Dall, 1889) -- valid
  Inodrillia amblytera (Bush, 1893) -- valid
  Inodrillia avira Bartsch, 1943 -- valid
  Inodrillia carpenteri (A. E. Verrill and S. Smith, 1880 -- valid
  Inodrillia dalli (A. E. Verrill and S. Smith, 1882) -- valid
  Inodrillia dido Bartsch, 1943 -- valid
  Inodrillia gibba Bartsch, 1943 -- valid
  Inodrillia hatterasensis Bartsch, 1943 -- valid
  Inodrillia ino Bartsch, 1943 -- valid
  Inodrillia martha Bartsch, 1943 -- valid
  Inodrillia miamia Bartsch, 1943 -- valid
  Inodrillia nucleata (Dall, 1881) -- valid
  Inodrillia vetula Bartsch, 1943 -- valid
  Io Lea, 1831 -- valid
  Io fluvialis (Say, 1825) -- valid -- Spiny Riversnail
  Iothia Forbes, 1849 -- valid
  Iothia lindbergi J. H. McLean, 1985 -- valid
  Iphigenia Schumacher, 1817 -- valid
  Iphigenia brasiliana (Lamarck, 1818) -- valid -- giant false coquina, giant coquina
  Iphitus Jeffreys, 1883 -- valid
  Iphitus robertsi Sabelli and Taviani, 1997 -- valid
  Irusella Hertlein and Grant, 1972 -- valid
  Irusella lamellifera (Conrad, 1837) -- valid -- lamellar venus
  Ischadium Jukes-Browne, 1905 -- valid
  Ischadium recurvum (Rafinesque, 1820) -- valid -- hooked mussel
  Ischnochiton Gray, 1847 -- valid
  Ischnochiton alascensis Thiele, 1910 -- valid
  Ischnochiton allyni Ferreira, 1977 -- invalid
  Ischnochiton boogi Haddon, 1886 -- invalid
  Ischnochiton dilatosculptus Kaas, 1982 -- valid
  Ischnochiton erythronotus (C. B. Adams, 1845) -- valid -- multihued chiton
  Ischnochiton hartmeyeri Thiele, 1910 -- valid -- multiringed chiton
  Ischnochiton interstinctus Gould, 1846 -- invalid
  Ischnochiton newcombi Pilsbry, 1892 -- valid
  Ischnochiton niveus Ferreira, 1987 -- valid
  Ischnochiton papillosus (C. B. Adams, 1845) -- valid
  Ischnochiton pseudovirgatus Kaas, 1972 -- valid -- blue-spot chiton
  Ischnochiton regularis (Carpenter, 1855) -- invalid
  Ischnochiton scrobiculatus (Middendorff, 1847) -- valid
  Ischnochiton striolatus (J. E. Gray, 1828) -- valid
  Ischnochiton trifidus Carpenter, 1864 -- invalid
  Ischnochitonidae Dall, 1889 -- valid
  Iselica Dall, 1918 -- valid
  Iselica anomala (C. B. Adams, 1850) -- valid
  Iselica obtusa (Carpenter, 1864) -- valid
  Iselica ovoidea (Gould, 1853) -- valid
  Isognomon Lightfoot, 1786 -- valid
  Isognomon alatus (Gmelin, 1791) -- valid -- flat tree-oyster
  Isognomon bicolor (C. B. Adams, 1845) -- valid -- bicolored purse-oyster, bicolor purse-oyster
  Isognomon janus Carpenter, 1857 -- valid -- thin purse-oyster
  Isognomon radiatus (Anton, 1839) -- valid -- lister purse-oyster, radial purse-oyster
  Isognomon recognitus (Mabille, 1895) -- valid -- purple purse-oyster
  Isognomonidae Woodring, 1925 -- valid
  Isorobitella Keen, 1962 -- valid
  Isorobitella trigonalis (Carpenter, 1857) -- valid -- trigonal montacutid
  Issena Iredale and O'Donoghue, 1923 -- invalid
  Issena pacifica (Bergh, 1894) -- invalid
  Issena ramosa (A. E. Verrill and Emerton, 1881) -- invalid
  Ithycythara Woodring, 1928 -- valid
  Ithycythara auberiana (d'Orbigny, 1842) -- valid
  Ithycythara cymella (Dall, 1889) -- valid
  Ithycythara lanceolata (C. B. Adams, 1850) -- valid
  Ithycythara parkeri Abbott, 1958 -- valid
  Ithycythara pentagonalis (Reeve, 1845) -- valid
  Ithycythara psila (Bush, 1885) -- valid
  Ividella Dall and Bartsch, 1909 -- valid
  Ividella navisa (Dall and Bartsch, 1907) -- valid
  Ividia Dall and Bartsch, 1904 -- valid
  Ividia abbotti (Olsson and McGinty, 1958) -- valid
  Ividia havanensis (Pilsbry and Aguayo, 1933) -- valid
  Janolidae Pruvot-Fol, 1933 -- invalid
  Janolus Bergh, 1884 -- valid
  Janolus barbarensis (J. G. Cooper, 1863) -- valid -- cockscomb nudibranch
  Janolus comis Er. Marcus, 1955 -- valid
  Janolus fuscus O'Donohue, 1924 -- valid
  Janolus mucloc (Er. Marcus, 1958) -- valid
  Janthina Röding, 1798 -- valid
  Janthina exigua Lamarck, 1816 -- valid -- dwarf janthina
  Janthina globosa Swainson, 1822 -- valid -- elongate janthina
  Janthina janthina (Linnaeus, 1758) -- valid -- janthina
  Janthina pallida W. Thompson, 1840 -- valid -- pale janthina
  Janthinidae Leach, 1823 -- invalid
  Japonactaeon I. Taki, 1956 -- valid
  Japonactaeon pusillus (Forbes, 1843) -- valid -- miniature baby-bubble
  Jaspidella Olsson, 1956 -- valid
  Jaspidella blanesi (Ford, 1898) -- valid
  Jaspidella jaspidea (Gmelin, 1791) -- valid -- jasper dwarf olive
  Jaspidella miris Olsson, 1956 -- valid
  Jorunna Bergh, 1876 -- valid
  Jorunna pardus Behrens and R. Henderson, 1981 -- valid -- leopard jorunna
  Jouannetia Desmoulins, 1828 -- valid
  Jouannetia quillingi Turner, 1955 -- valid -- quilling piddock, spiny piddock
  Juga H. Adams and A. Adams, 1854 -- valid
  Juga acutifilosa (Stearns, 1890) -- valid -- Topaz Juga
  Juga bulbosa (Gould, 1847) -- valid -- Bulb Juga
  Juga hemphilli (J. Henderson, 1935) -- valid -- Barren Juga
  Juga interioris (Goodrich, 1944) -- valid -- Smooth Juga
  Juga laurae (Goodrich, 1944) -- valid -- Oasis Juga
  Juga nigrina (Lea, 1856) -- valid -- Black Juga
  Juga occata (Hinds, 1844) -- valid -- Scalloped Juga
  Juga plicifera (Lea, 1838) -- valid -- Pleated Juga
  Juga silicula (Gould, 1847) -- valid -- Glassy Juga
  Juliacorbula Olsson and Harbison, 1953 -- valid
  Juliacorbula cubaniana (d'Orbigny, 1842) -- valid -- Cuba corbula
  Juliacorbula luteola (Carpenter, 1864) -- valid -- western corbula
  Juliidae E. A. Smith, 1885 -- valid
  Juvenichiton Sirenko, 1975 -- valid
  Juvenichiton deplanatus (Sirenko, 1975) -- valid
  Juvenichiton saccharinus (Dall, 1878) -- valid
  Kaiparapelta B. A. Marshall, 1986 -- valid
  Kaiparapelta askewi J. H. McLean and Harasewych, 1995 -- valid
  Katharina Gray, 1847 -- valid
  Katharina tunicata (W. Wood, 1815) -- valid -- black katy
  Kelletia P. Fischer, 1884 -- valid
  Kelletia kelletii (Forbes, 1850) -- valid
  Kellia Turton, 1822 -- valid
  Kellia laperousii (Deshayes, 1839) -- invalid -- La Perouse kellyclam
  Kellia suborbicularis (Montagu, 1803) -- valid -- suborbicular kellyclam
  Kentrodorididae Bergh, 1891 -- invalid
  Kleinella A. Adams, 1860 -- valid
  Kleinella cedrosa (Dall, 1884) -- valid
  Kurtzia Bartsch, 1944 -- valid
  Kurtzia arteaga (Dall and Bartsch, 1910) -- valid -- beaded mangelia
  Kurtziella Dall, 1918 -- valid
  Kurtziella accincta (Montagu, 1808) -- valid
  Kurtziella atrostyla (Tryon, 1884) -- valid -- brown-tip mangelia
  Kurtziella cerina (Kurtz and Stimpson, 1851) -- valid
  Kurtziella citronella (Dall, 1886) -- valid -- yellow mangelia
  Kurtziella dorvilliae (Reeve, 1845) -- valid
  Kurtziella limonitella (Dall, 1884) -- valid -- punctate mangelia
  Kurtziella newcombei (Dall, 1919) -- valid
  Kurtziella perryae Bartsch and Rehder, 1939 -- valid
  Kurtziella plumbea (Hinds, 1843) -- valid -- violet-band mangelia
  Kurtziella variegata (Carpenter, 1864) -- valid -- tan mangelia
  Kurtzina Bartsch, 1944 -- valid
  Kurtzina beta (Dall, 1919) -- valid
  Kylix Dall, 1919 -- valid
  Kylix halocydne (Dall, 1919) -- valid
  Lacteoluna Pilsbry, 1926 -- valid
  Lacteoluna selenina (Gould, 1848) -- valid -- moonlight mudcloak
  Lacuna Turton, 1827 -- valid
  Lacuna carinata Gould, 1848 -- valid -- carinate lacuna
  Lacuna crassior (Montagu, 1803) -- valid -- thick lacuna
  Lacuna marmorata Dall, 1919 -- valid -- chink snail
  Lacuna pallidula (E. M. da Costa, 1778) -- valid -- pale lacuna
  Lacuna parva (E. M. da Costa, 1778) -- valid -- tiny lacuna
  Lacuna porrecta Carpenter, 1864 -- valid
  Lacuna succinea S. S. Berry, 1953 -- valid -- amber lacuna
  Lacuna unifasciata Carpenter, 1856 -- valid -- one-band lacuna
  Lacuna vaginata (Dall, 1918) -- valid -- delightful lacuna
  Lacuna variegata Carpenter, 1864 -- valid -- variegate lacuna
  Lacuna vincta (Montagu, 1803) -- valid -- northern lacuna
  Laemodonta Philippi, 1846 -- valid
  Laemodonta cubensis (Pfeiffer, 1854) -- valid -- Cuba dwarf pedipes
  Laevapex Walker, 1903 -- valid
  Laevapex diaphanus (Haldeman, 1841) -- invalid -- cymbal ancylid
  Laevapex fuscus (C. B. Adams, 1841) -- valid -- Dusky Ancylid
  Laevapex peninsulae (Pilsbry, 1903) -- invalid -- peninsula ancylid
  Laevicardium Swainson, 1840 -- valid
  Laevicardium elatum (G. B. Sowerby I, 1833) -- valid -- giant eggcockle
  Laevicardium laevigatum (Linnaeus, 1758) -- valid -- eggcockle
  Laevicardium mortoni (Conrad, 1830) -- valid -- morton eggcockle, yellow eggcockle
  Laevicardium pictum (Ravenel, 1861) -- valid -- painted eggcockle
  Laevicardium substriatum (Conrad, 1837) -- valid -- Pacific eggcockle
  Laevicardium sybariticum (Dall, 1886) -- valid -- delicate eggcockle
  Laevicaulis Simroth, 1913 -- valid
  Laevicaulis alte (Ferussac, 1821) -- valid -- tropical leatherleaf
  Laevichlamys Waller, 1993 -- valid
  Laevichlamys multisquamata (Dunker, 1864) -- valid -- many-ribbed scallop
  Laevinesta Pilsbry and McGinty, 1952 -- valid
  Laevinesta atlantica (Perez Farfante, 1947) -- valid -- Atlantic nesta
  Laevipilina McLean, 1979 -- valid
  Laevipilina hyalina J. H. McLean, 1979 -- valid
  Laevipilinidae -- invalid
  Laila MacFarland, 1905 -- valid
  Laila cockerelli MacFarland, 1905 -- valid
  Lamellaria Montagu, 1815 -- valid
  Lamellaria diegoensis Dall, 1885 -- valid -- San Diego lamellaria
  Lamellaria digueti Rochebrune, 1895 -- valid
  Lamellaria koto Schwengel, 1944 -- valid
  Lamellaria leucosphaera Schwengel, 1942 -- valid -- white-ball lamellaria
  Lamellaria perspicua (Linnaeus, 1758) -- valid -- transparent lamellaria
  Lamellariidae d'Orbigny, 1841 -- invalid
  Lamellaxis Strebel and Pfeffer, 1882 -- valid
  Lamellaxis micra (d'Orbigny, 1835) -- valid -- tiny awlsnail
  Lamellitrochus Quinn, 1991 -- valid
  Lamellitrochus carinatus Quinn, 1991 -- valid -- keeled solarelle
  Lamellitrochus inceratus Quinn, 1991 -- valid -- waxy solarelle
  Lamellitrochus lamellosus (A. E. Verrill and S. Smith, 1880) -- valid -- lamellose solarelle
  Lampeia MacGinitie, 1959 -- valid
  Lampeia adamsi (MacGinitie, 1959) -- valid -- pillar thraciid
  Lampsilis Rafinesque, 1820 -- valid
  Lampsilis abrupta (Say, 1831) -- valid -- pink mucket
  Lampsilis altilis (Conrad, 1834) -- invalid -- finelined pocketbook
  Lampsilis australis Simpson, 1900 -- invalid -- southern sandshell
  Lampsilis binominata Simpson, 1900 -- valid -- lined pocketbook
  Lampsilis bracteata (Gould, 1855) -- valid -- Texas fatmucket
  Lampsilis cardium Rafinesque, 1820 -- valid -- plain pocketbook
  Lampsilis cariosa (Say, 1817) -- valid -- yellow lampmussel
  Lampsilis dolabraeformis (Lea, 1838) -- valid -- Altamaha pocketbook
  Lampsilis fasciola Rafinesque, 1820 -- valid -- wavy-rayed lampmussel, wavyrayed lampmussel
  Lampsilis fullerkati R. I. Johnson, 1984 -- invalid -- Waccamaw fatmucket
  Lampsilis haddletoni Athearn, 1964 -- invalid -- Haddleton lampmussel
  Lampsilis higginsii (Lea, 1857) -- valid -- Higgins' eye, Higgins' eye pearly mussel
  Lampsilis hydiana (Lea, 1838) -- valid -- Louisiana fatmucket
  Lampsilis ornata (Conrad, 1835) -- valid -- southern pocketbook
  Lampsilis ovata (Say, 1817) -- valid -- pocketbook
  Lampsilis perovalis (Conrad, 1834) -- invalid -- orange-nacre mucket, orangenacre mucket
  Lampsilis powellii (Lea, 1852) -- valid -- Arkansas fatmucket
  Lampsilis radiata (Gmelin, 1791) -- valid -- eastern lampmussel
  Lampsilis radiata conspicua (Lea, 1872) -- invalid
  Lampsilis radiata radiata (Gmelin, 1791) -- invalid -- eastern lampmussel
  Lampsilis rafinesqueana Frierson, 1927 -- valid -- Neosho mucket
  Lampsilis reeveiana (Lea, 1852) -- valid -- Arkansas brokenray, Arkansas broken-ray
  Lampsilis reeveiana brevicula (Call, 1887) -- invalid -- Ozark broken-ray
  Lampsilis reeveiana brittsi Simpson, 1900 -- invalid -- northern broken-ray
  Lampsilis reeveiana reeveiana (Lea, 1852) -- invalid -- Arkansas broken-ray
  Lampsilis satura (Lea, 1852) -- valid -- sandbank pocketbook
  Lampsilis siliquoidea (Barnes, 1823) -- valid -- fatmucket
  Lampsilis splendida (Lea, 1838) -- valid -- rayed pink fatmucket
  Lampsilis straminea (Conrad, 1834) -- valid -- rough fatmucket
  Lampsilis straminea claibornensis (Lea, 1838) -- invalid -- southern fatmucket
  Lampsilis straminea straminea (Conrad, 1834) -- invalid -- rough fatmucket
  Lampsilis streckeri Frierson, 1927 -- valid -- speckled pocketbook
  Lampsilis subangulata (Lea, 1840) -- invalid -- shiny-rayed pocketbook, shinyrayed pocketbook
  Lampsilis teres (Rafinesque, 1820) -- valid -- yellow sandshell
  Lampsilis virescens (Lea, 1858) -- valid -- Alabama lamp mussel, Alabama lamp pearly mussel, Alabama lampmussel
  Lanx Clessin, 1882 -- valid
  Lanx alta (Tryon, 1865) -- valid -- Highcap Lanx
  Lanx klamathensis Hannibal, 1912 -- invalid -- Scale Lanx
  Lanx patelloides (Lea, 1856) -- valid -- Kneecap Lanx
  Lanx subrotunda (Tryon, 1865) -- invalid -- Rotund Lanx
  Lapinura Er. Marcus and Ev. Marcus, 1970 -- valid
  Lapinura divae (Ev. Marcus and Er. Marcus, 1963) -- valid
  Lasaea T. Brown, 1827 -- valid
  Lasaea adansoni (Gmelin, 1791) -- valid -- adanson lepton, reddish lepton
  Lasaeidae Gray, 1842 -- valid
  Laseadae Gray, 1842 -- invalid
  Lasmigona Rafinesque, 1831 -- valid
  Lasmigona complanata (Barnes, 1823) -- valid -- white heelsplitter
  Lasmigona complanata alabamensis Clarke, 1985 -- invalid
  Lasmigona complanata complanata (Barnes, 1823) -- invalid -- white heelsplitter
  Lasmigona compressa (Lea, 1829) -- valid -- creek heelsplitter
  Lasmigona costata (Rafinesque, 1820) -- valid -- fluted-shell, flutedshell
  Lasmigona decorata (Lea, 1852) -- valid -- Carolina heelsplitter
  Lasmigona holstonia (Lea, 1838) -- valid -- Tennessee heelsplitter
  Lasmigona subviridis (Conrad, 1835) -- valid -- green floater
  Latirus Montfort, 1810 -- valid
  Latirus angulatus (Roding, 1798) -- valid -- short-tail latirus
  Latirus carinifer Lamarck, 1822 -- valid -- yellow latirus
  Latirus infundibulum (Gmelin, 1791) -- valid -- brown-line latirus
  Latirus nematus Woodring, 1928 -- valid -- threaded latirus
  Learchis Bergh, 1896 -- valid
  Learchis poica Ev. Marcus and Er. Marcus, 1960 -- valid
  Ledella A. E. Verrill and Bush, 1897 -- valid
  Ledella fiascona (Dall, 1916) -- valid -- Baja miniature nutclam
  Lehmannia Heynemann, 1863 -- valid
  Lehmannia valentiana (Ferussac, 1821) -- valid -- threeband gardenslug
  Leidyula H. B. Baker, 1925 -- valid
  Leidyula floridana (Leidy, 1851) -- valid -- Florida leatherleaf
  Leidyula kraussi (Ferussac, 1823) -- valid -- dappled leatherleaf
  Leidyula moreleti (Crosse and P. Fischer, 1872) -- valid -- tan leatherleaf
  Leiomya A. Adams, 1864 -- valid
  Leiomya claviculata (Dall, 1881) -- valid -- clavicle myoneria
  Lemiox Rafinesque, 1831 -- valid
  Lemiox rimosus (Rafinesque, 1831) -- valid -- birdwing pearlymussel, birdwing pearly mussel
  Lepeta J. E. Gray, 1842 -- valid
  Lepeta caeca (Muller, 1776) -- valid -- northern blind limpet
  Lepetidae Gray, 1850 -- valid
  Lepidochitona Gray, 1821 -- valid
  Lepidochitona aleutica (Dall, 1879) -- valid
  Lepidochitona beanii (Carpenter, 1864) -- valid
  Lepidochitona berryana Eernisse, 1986 -- valid
  Lepidochitona caverna Eernisse, 1986 -- valid
  Lepidochitona dentiens (Gould, 1846) -- valid
  Lepidochitona fernaldi Eernisse, 1986 -- valid
  Lepidochitona flectens (Carpenter, 1864) -- valid
  Lepidochitona gothica (Carpenter, 1864) -- valid
  Lepidochitona hartwegii (Carpenter, 1855) -- valid
  Lepidochitona heathii (Pilsbry, 1898) -- invalid
  Lepidochitona keepiana S. S. Berry, 1948 -- valid
  Lepidochitona liozonis (Dall and Simpson, 1901) -- valid -- Caribbean red chiton
  Lepidochitona lobium (S. S. Berry, 1925) -- invalid
  Lepidochitona lowei (Pilsbry, 1918) -- valid
  Lepidochitona lowei fackenthallae (S. S. Berry, 1919) -- invalid
  Lepidochitona semilirata (S. S. Berry, 1927) -- valid
  Lepidochitona thamnopora (S. S. Berry, 1911) -- valid
  Lepidochitona thomasi (Pilsbry, 1898) -- valid
  Lepidopleuridae Pilsbry, 1892 -- invalid
  Lepidozona Pilsbry, 1892 -- valid
  Lepidozona allyni (Ferreira, 1977) -- valid
  Lepidozona cooperi (Dall, 1879) -- valid
  Lepidozona ima Sirenko, 1975 -- valid
  Lepidozona interstincta (Gould, 1846) -- valid
  Lepidozona mertensii (Middendorff, 1847) -- valid
  Lepidozona pectinulata (Carpenter, 1893) -- valid
  Lepidozona regularis (Carpenter, 1855) -- valid
  Lepidozona retiporosa (Carpenter, 1864) -- valid
  Lepidozona scabricostata (Carpenter, 1864) -- valid
  Lepidozona serrata (Carpenter, 1864) -- valid
  Lepidozona sinudentata (Carpenter, 1892) -- valid
  Lepidozona trifida (Carpenter, 1864) -- valid
  Lepidozona willetti (S. S. Berry, 1917) -- valid
  Leporimetis Iredale, 1930 -- valid
  Leporimetis intastriata (Say, 1827) -- valid -- atlantic fat tellin, Atlantic fat-tellin
  Leporimetis obesa (Deshayes, 1855) -- valid -- california fat tellin, California fat-tellin
  Leptadrillia Woodring, 1928 -- valid
  Leptadrillia cookei (E. A. Smith, 1888) -- valid
  Leptaxinus A. E. Verrill and Bush, 1898 -- valid
  Leptaxinus minutus A. E. Verrill and Bush, 1898 -- valid -- minute axinopsid
  Leptochiton Gray, 1847 -- valid
  Leptochiton alveolus (M. Sars in Lovén, 1846) -- valid
  Leptochiton arcticus (G. O. Sars, 1878) -- valid
  Leptochiton nexus Carpenter, 1864 -- valid
  Leptochiton rugatus (Pilsbry, 1892) -- valid
  Leptodea Rafinesque, 1820 -- invalid
  Leptodea fragilis (Rafinesque, 1820) -- invalid -- fragile papershell
  Leptodea leptodon (Rafinesque, 1820) -- invalid -- scaleshell
  Leptodea ochracea (Say, 1817) -- invalid -- tidewater mucket
  Leptogyra Bush, 1897 -- valid
  Leptogyra alaskana Bartsch, 1910 -- valid
  Lepton Turton, 1822 -- valid
  Lepton lepidum Say, 1826 -- valid -- graceful lepton
  Leptopecten A. E. Verrill, 1897 -- valid
  Leptopecten latiauratus (Conrad, 1837) -- valid -- kelp scallop
  Leptoxis Rafinesque, 1819 -- valid
  Leptoxis ampla (Anthony, 1855) -- valid -- Round Rocksnail
  Leptoxis arkansensis (Hinkley, 1915) -- valid -- Arkansas Mudalia
  Leptoxis carinata (Bruguiere, 1792) -- valid -- Crested Mudalia
  Leptoxis clipeata (H. H. Smith in Goodrich, 1922) -- valid -- Agate Rocksnail
  Leptoxis compacta (Anthony, 1854) -- valid -- Oblong Rocksnail
  Leptoxis crassa (Haldeman, 1841) -- invalid -- boulder snail, boulder riversnail
  Leptoxis crassa anthonyi (Redfield, 1854) -- invalid
  Leptoxis crassa crassa (Haldeman, 1841) -- invalid -- boulder riversnail
  Leptoxis dilatata (Conrad, 1835) -- valid -- Seep Mudalia
  Leptoxis foremani (Lea, 1843) -- valid -- Interrupted Rocksnail
  Leptoxis formosa (Lea, 1860) -- valid -- Maiden Rocksnail
  Leptoxis ligata (Anthony, 1860) -- valid -- Rotund Rocksnail
  Leptoxis lirata (H. H. Smith in Goodrich, 1922) -- valid -- Lirate Rocksnail
  Leptoxis melanoides (Conrad, 1834) -- invalid -- black mudalia
  Leptoxis minor (Hinkley, 1912) -- valid -- Knob Mudalia
  Leptoxis occultata (H. H. Smith in Goodrich, 1922) -- valid -- Bigmouth Rocksnail
  Leptoxis picta (Conrad, 1834) -- valid -- Spotted Rocksnail
  Leptoxis plicata (Conrad, 1834) -- valid -- Plicate Rocksnail
  Leptoxis praerosa (Say, 1821) -- valid -- Onyx Rocksnail
  Leptoxis showalterii (Lea, 1860) -- valid -- Coosa Rocksnail
  Leptoxis taeniata (Conrad, 1834) -- invalid -- Painted Rocksnail
  Leptoxis torrefacta (H. H. Smith in Goodrich, 1922) -- valid -- Squat Rocksnail
  Leptoxis trilineata (Say, 1829) -- valid -- Broad Mudalia
  Leptoxis umbilicata (Wetherby, 1876) -- valid -- Umbilicate Rocksnail
  Leptoxis virgata (Lea, 1841) -- valid -- Smooth Mudalia
  Leptoxis vittata (Lea, 1860) -- valid -- Striped Rocksnail
  Lepyrium Pilsbry and Olsson, 1951 -- valid
  Lepyrium showalteri (Lea, 1861) -- valid -- Flat Pebblesnail
  Leuconopsis Hutton, 1884 -- valid
  Leuconopsis novimundi (Pilsbry and McGinty, 1949) -- valid
  Leucosyrinx Dall, 1889 -- valid
  Leucosyrinx kincaidi Dall, 1919 -- valid
  Leucozonia Gray, 1847 -- valid
  Leucozonia jacarusoi Petuch, 1987 -- valid
  Leucozonia nassa (Gmelin, 1791) -- valid -- chestnut latirus
  Leucozonia ocellata (Gmelin, 1791) -- valid -- white-spot latirus
  Lexingtonia Ortmann, 1914 -- invalid
  Lexingtonia dolabelloides (Lea, 1840) -- invalid -- slabside pearly mussel
  Lexingtonia subplana (Conrad, 1837) -- invalid -- Virginia pigtoe
  Ligumia Swainson, 1840 -- valid
  Ligumia nasuta (Say, 1817) -- invalid -- eastern pondmussel
  Ligumia recta (Lamarck, 1819) -- valid -- black sandshell
  Ligumia subrostrata (Say, 1831) -- invalid -- pondmussel
  Liguus Montfort, 1810 -- valid
  Liguus fasciatus (Muller, 1774) -- valid -- Florida treesnail
  Lima Bruguiere, 1789 -- valid
  Lima excavata (Fabricius, 1779) -- valid -- excavated fileclam
  Lima floridana Olsson and Harbison, 1953 -- valid -- smooth fileclam
  Lima lima (Linnaeus, 1758) -- valid -- spiny fileclam
  Lima locklini McGinty, 1955 -- valid -- locklin fileclam, skewed fileclam
  Lima scabra (Born, 1778) -- valid -- rough fileclam
  Limacidae Batsch, 1789 -- valid
  Limacina Bosc, 1817 -- valid
  Limacina bulimoides (d'Orbigny, 1836) -- valid -- bulimoid pteropod
  Limacina helicina (Phipps, 1774) -- valid -- helicid pteropod
  Limacina inflata (d'Orbigny, 1836) -- valid -- planorbid pteropod
  Limacina lesueurii (d'Orbigny, 1836) -- valid
  Limacina retroversa (Fleming, 1823) -- valid -- retrovert pteropod
  Limacina trochiformis (d'Orbigny, 1836) -- valid -- trochiform pteropod
  Limacinidae Blainville, 1823 -- invalid
  Limapontia Johnston, 1836 -- valid
  Limapontia zonata (Girard, 1852) -- valid
  Limapontiidae Gray, 1847 -- valid
  Limaria Link, 1807 -- valid
  Limaria hemphilli (Hertlein and Strong, 1946) -- valid -- phemphill fileclam, Hemphill fileclam
  Limaria pellucida (C. B. Adams, 1846) -- valid -- Antillean fileclam
  Limatula S. V. Wood, 1839 -- valid
  Limatula attenuata Dall, 1916 -- valid -- attenuate fileclam
  Limatula confusa (E. A. Smith, 1885) -- valid -- confusing fileclam
  Limatula hendersoni Olsson and McGinty, 1958 -- valid -- henderson fileclam, minute fileclam
  Limatula hyalina A. E. Verrill and Bush, 1898 -- valid -- ahyaline fileclam, hyaline fileclam
  Limatula hyperborea A. S. Jensen, 1909 -- valid -- boreal fileclam, Arctic fileclam
  Limatula japonica A. Adams, 1864 -- valid -- Japan fileclam
  Limatula regularis A. E. Verrill and Bush, 1898 -- valid -- aregular fileclam, regular fileclam
  Limatula saturna Bernard, 1978 -- valid -- saturnine fileclam, Saturna fileclam
  Limatula setifera Dall, 1886 -- valid -- bristly fileclam
  Limatula similaris (Dall, 1908) -- valid -- furrowless fileclam
  Limatula subauriculata (Montagu, 1808) -- valid -- small-ear fileclam
  Limax Linnaeus, 1758 -- valid
  Limax flavus Linnaeus, 1758 -- valid -- yellow garden slug, yellow gardenslug
  Limax marginatus Muller, 1774 -- valid -- tree slug
  Limax maximus Linnaeus, 1758 -- valid -- giant garden slug, giant gardenslug
  Limax nyctelius Bourguignat, 1861 -- valid -- false tree slug, vine slug
  Limea Bronn, 1831 -- valid
  Limea bronniana Dall, 1886 -- valid -- bronn fileclam, dwarf fileclam
  Limea subovata (Jeffreys, 1876) -- valid -- subovate fileclam
  Limidae Rafinesque, 1815 -- valid
  Limifossor Heath, 1904 -- valid
  Limifossor fratula Heath, 1911 -- valid -- southern mole glistenworm
  Limifossor talpoideus Heath, 1911 -- valid -- northern mole glistenworm
  Limifossoridae Salvini-Plawen, 1968 -- valid
  Limoida -- invalid
  Limopsidae Dall, 1895 -- valid
  Limopsis Sasso, 1827 -- valid
  Limopsis akutanica Dall, 1916 -- valid -- Akutan limops
  Limopsis antillensis Dall, 1881 -- valid -- Antillean limops
  Limopsis aurita (Brocchi, 1814) -- valid -- eared limops
  Limopsis cristata Jeffreys, 1876 -- valid -- crested limops
  Limopsis minuta Philippi, 1836 -- valid -- minute limops
  Limopsis panamensis Dall, 1902 -- valid -- Panamic limops
  Limopsis sulcata A. E. Verrill and Bush, 1898 -- valid -- asulcate limops, sulcate limops
  Linatella Gray, 1857 -- valid
  Linatella caudata (Gmelin, 1791) -- valid -- ringed triton
  Lindapecten Petuch, 1995 -- valid
  Lindapecten exasperatus (G. B. Sowerby II, 1842) -- valid -- thistle scallop
  Lindapecten lindae Petuch, 1995 -- valid
  Lindapecten muscosus (W. Wood, 1828) -- valid -- rough scallop
  Linisa Pilsbry, 1930 -- valid
  Linisa tamaulipasensis (I. Lea, 1857) -- valid -- dryland liptooth
  Linisa texasiana (Moricand, 1833) -- valid -- Texas liptooth
  Lioberus Dall, 1898 -- valid
  Lioberus castaneus (Say, 1822) -- valid -- chestnut mussel
  Liocyma fluctuosum (Gould, 1841) -- valid -- wavy liocyma, varnished liocyma
  Liocyma viride Dall, 1871 -- invalid -- green liocyma
  Liomesus Stimpson, 1865 -- valid
  Liomesus nassula Dall, 1901 -- valid -- basket whelk
  Liomesus nux Dall, 1877 -- invalid -- nut whelk
  Liomesus ooides (Middendorff, 1848) -- invalid -- egg whelk
  Liomesus stimpsoni Dall, 1889 -- valid
  Lioplax Troschel, 1857 -- valid
  Lioplax cyclostomaformis (Lea, 1841) -- valid -- Cylindrical Lioplax
  Lioplax pilsbryi Walker, 1905 -- valid -- Choctaw Lioplax
  Lioplax subcarinata (Say, 1817) -- valid -- Ridgid Lioplax
  Lioplax sulculosa (Menke, 1827) -- valid -- furrowed lioplax
  Lioplax talquinensis Vail, 1979 -- invalid
  Liostomia G. O. Sars, 1878 -- valid
  Liostomia eburnea (Stimpson, 1851) -- valid
  Liotia G. B. Sowerby I, 1834 -- valid
  Liotia fenestrata Carpenter, 1864 -- valid -- California cyclostreme
  Lirabuccinum Vermeij, 1991 -- valid
  Lirabuccinum dirum (Reeve, 1846) -- valid -- dire whelk
  Lirobarleeia Ponder, 1983 -- valid
  Lirobarleeia kelseyi (Dall and Bartsch, 1902) -- valid
  Lirobittium Bartsch, 1911 -- valid
  Lirobittium armillatum (Carpenter, 1864) -- valid
  Lirobittium attenuatum (Carpenter, 1864) -- valid -- slender cerith
  Lirobittium fetellum (Bartsch, 1911) -- valid
  Lirobittium interfossum (Carpenter, 1864) -- valid
  Lirobittium johnstonae Bartsch, 1911 -- valid
  Lirobittium larum (Bartsch, 1911) -- valid
  Lirobittium lomaense (Bartsch, 1911) -- valid
  Lirobittium munitum (Carpenter, 1864) -- valid
  Lirobittium oldroydae Bartsch, 1911 -- valid
  Lirobittium purpureum (Carpenter, 1864) -- valid
  Lirobittium quadrifilatum (Carpenter, 1864) -- valid -- four-thread cerith
  Lirobittium rugatum (Carpenter, 1864) -- valid
  Lirobittium serra Bartsch, 1917 -- valid
  Lirophora Conrad, 1883 -- valid
  Lirophora clenchi (Pulley, 1952) -- valid -- Clench venus, thick-ringed venus
  Lirophora latilirata (Conrad, 1841) -- valid -- imperial venus
  Lirularia Dall, 1909 -- valid
  Lirularia acuticostata (Carpenter, 1864) -- valid -- sharp-rib lirularia
  Lirularia bicostata (J. H. McLean, 1964) -- valid -- two-rib margarite
  Lirularia discors J. H. McLean, 1984 -- valid -- incongruous lirularia
  Lirularia lirulata (Carpenter, 1864) -- valid -- lirulate margarite
  Lirularia optabilis (Carpenter, 1864) -- valid -- choice margarite
  Lirularia parcipicta (Carpenter, 1864) -- valid -- few-spotted lirularia, few-spot lirularia
  Lirularia succincta (Carpenter, 1864) -- valid -- girdled lirularia
  Lissodrillia Bartsch and Rehder, 1939 -- valid
  Lissodrillia schroederi (Bartsch and Rehder, 1939) -- valid
  Lissodrillia simpsoni (Dall, 1887) -- valid
  Lithasia Haldeman, 1840 -- valid
  Lithasia armigera (Say, 1821) -- valid -- Armored Rocksnail
  Lithasia curta Lea, 1868 -- valid -- Knobby Rocksnail
  Lithasia duttoniana (Lea, 1841) -- valid -- Helmet Rocksnail
  Lithasia geniculata Haldeman, 1840 -- valid -- Ornate Rocksnail
  Lithasia hubrichti Clench, 1956 -- valid -- Big Black Rocksnail
  Lithasia jayana (Lea, 1841) -- valid -- Rugose Rocksnail
  Lithasia lima (Conrad, 1834) -- valid -- Warty Rocksnail
  Lithasia obovata (Say, 1829) -- valid -- Shawnee Rocksnail
  Lithasia salebrosa (Conrad, 1834) -- valid -- Muddy Rocksnail
  Lithasia verrucosa (Rafinesque, 1820) -- valid -- Varicose Rocksnail
  Lithophaga Roding, 1798 -- valid
  Lithophaga antillarum (d'Orbigny, 1842) -- valid -- giant datemussel
  Lithophaga aristata (Dillwyn, 1817) -- valid -- scissor datemussel
  Lithophaga attenuata (Deshayes, 1836) -- valid -- attenuated datemussel
  Lithophaga bisulcata (d'Orbigny, 1842) -- valid -- mahogany datemussel
  Lithophaga nigra (d'Orbigny, 1842) -- valid -- black datemussel
  Lithophaga plumula (Hanley, 1844) -- valid -- feather datemussel
  Lithophaga plumula kelseyi Hertlein and Strong, 1946 -- invalid -- kelsey datemussel
  Lithopoma Gray, 1850 -- valid
  Lithopoma americanum (Gmelin, 1791) -- valid -- american starsnail
  Lithopoma caelatum (Gmelin, 1791) -- valid -- carved starsnail
  Lithopoma gibberosa (Dillwyn, 1817) -- valid -- red turban
  Lithopoma tectum (Lightfoot, 1786) -- valid -- West Indian starsnail
  Lithopoma tuber (Linnaeus, 1767) -- valid -- green starsnail
  Litiopa Rang, 1829 -- valid
  Litiopa melanostoma Rang, 1829 -- valid -- sargassum snail
  Litiopidae Gray, 1847 -- valid
  Littoraria Griffith and Pidgeon, 1834 -- valid
  Littoraria angulifera (Lamarck, 1822) -- valid -- mangrove periwinkle
  Littoraria irrorata (Say, 1822) -- valid -- marsh periwinkle
  Littoraria nebulosa (Lamarck, 1822) -- valid -- cloudy periwinkle
  Littoraria tessellata (Philippi, 1847) -- valid
  Littoridina Eydoux and Souleyet, 1852 -- valid
  Littoridina crosseana (Pilsbry, 1910) -- valid
  Littoridinops Pilsbry, 1952 -- valid
  Littoridinops monroensis (Frauenfeld, 1863) -- valid -- Cockscomb Hydrobe
  Littoridinops palustris F. G. Thompson, 1968 -- valid -- Bantam Hydrobe
  Littoridinops tenuipes (Couper, 1844) -- valid -- Henscomb Hydrobe
  Littorina Ferussac, 1822 -- valid
  Littorina aleutica Dall, 1872 -- valid
  Littorina keenae Rosewater, 1978 -- valid -- eroded periwinkle
  Littorina littorea (Linnaeus, 1758) -- valid -- common periwinkle
  Littorina obtusata (Linnaeus, 1758) -- valid -- yellow periwinkle
  Littorina plena Gould, 1849 -- valid
  Littorina saxatilis (Olivi, 1792) -- valid -- rough periwinkle
  Littorina scutulata Gould, 1849 -- valid -- checkered periwinkle
  Littorina sitkana Philippi, 1846 -- valid -- Sitka periwinkle
  Littorina squalida Broderip and G. B. Sowerby I, 1829 -- valid
  Littorina subrotundata (Carpenter, 1864) -- valid
  Littorinidae Gray, 1840 -- invalid
  Lobiger Krohn, 1847 -- valid
  Lobiger souverbii P. Fischer, 1857 -- valid
  Lobosculum Pilsbry, 1930 -- valid
  Lobosculum pustula (Ferussac, 1832) -- valid -- grooved liptooth
  Lobosculum pustuloides (Bland, 1858) -- valid -- tiny liptooth
  Loligo ocula Cohen, 1976 -- valid -- bigeye inshore squid
  Loligo opalescens Berry, 1911 -- valid -- california market squid, opalescent inshore squid
  Loligo pealeii Lesueur, 1821 -- valid -- longfin inshore squid
  Loligo plei Blainville, 1823 -- valid -- arrow squid, slender inshore squid
  Loligo roperi Cohen, 1976 -- valid -- roper squid, Roper inshore squid
  Lolliguncula brevis (Blainville, 1823) -- valid -- Atlantic brief squid
  Lomanotidae Bergh, 1890 -- valid
  Lomanotus Verany, 1844 -- valid
  Lomanotus vermiformis Eliot, 1908 -- valid
  Lottia G. B. Sowerby I, 1834 -- valid
  Lottia alveus (Conrad, 1831) -- valid -- bowl limpet
  Lottia alveus alveus (Conrad, 1831) -- valid -- bowl limpet
  Lottia alveus parallela (Dall, 1914) -- valid -- bowl limpet
  Lottia asmi (Middendorff, 1847) -- valid -- black limpet
  Lottia borealis (Lindberg, 1982) -- valid -- boreal limpet
  Lottia conus (Test, 1945) -- valid
  Lottia digitalis (Rathke, 1833) -- valid -- ribbed limpet
  Lottia gigantea G. B. Sowerby I, 1834 -- valid -- owl limpet
  Lottia instabilis (Gould, 1846) -- valid -- unstable limpet
  Lottia jamaicensis (Gmelin, 1791) -- valid -- Jamaica limpet
  Lottia leucopleura (Gmelin, 1791) -- valid -- black-rib limpet
  Lottia limatula (Carpenter, 1864) -- valid -- file limpet
  Lottia ochracea (Dall, 1871) -- valid -- yellow limpet
  Lottia painei Lindberg, 1987 -- valid
  Lottia pelta (Rathke, 1833) -- valid -- shield limpet
  Lottia scabra (Gould, 1846) -- valid -- rough limpet
  Lottia strigatella (Carpenter, 1864) -- valid
  Lottia triangularis (Carpenter, 1864) -- valid -- triangular limpet
  Lottiidae Gray, 1840 -- valid
  Lucapina G. B. Sowerby II, 1835 -- valid
  Lucapina aegis (Reeve, 1850) -- valid -- shield fleshy limpet
  Lucapina eolis Perez Farfante, 1945 -- valid
  Lucapina philippiana (Finlay, 1930) -- valid
  Lucapina sowerbii (G. B. Sowerby II, 1835) -- valid
  Lucapina suffusa (Reeve, 1850) -- valid -- cancellate fleshy limpet
  Lucapinella Pilsbry, 1890 -- valid
  Lucapinella callomarginata (Dall, 1871) -- valid -- rim fleshy limpet
  Lucapinella limatula (Reeve, 1850) -- valid -- file fleshy limpet
  Lucidella Swainson, 1840 -- valid
  Lucidella tantilla Pilsbry, 1902 -- valid -- ochre drop
  Lucina Lamarck, 1799 -- valid
  Lucina amianta (Dall, 1901) -- valid -- miniature lucine
  Lucina floridana Conrad, 1833 -- valid -- Florida lucine
  Lucina keenae Chavan, 1971 -- valid -- dosinia lucine
  Lucina leucocyma Dall, 1886 -- valid -- four-rib lucine
  Lucina pectinata (Gmelin, 1791) -- valid -- thick lucine
  Lucina pensylvanica (Linnaeus, 1758) -- valid -- Pennsylvania lucine
  Lucina sombrerensis Dall, 1886 -- valid -- Sombrero lucine
  Lucina trisulcata Conrad, 1841 -- valid -- three-ridge lucine
  Lucinidae Fleming, 1828 -- valid
  Lucinisca Dall, 1901 -- valid
  Lucinisca muricata (Spengler, 1798) -- valid -- spinose lucine
  Lucinisca nassula (Conrad, 1846) -- valid -- woven lucine
  Lucinisca nuttalli (Conrad, 1837) -- valid -- Nuttall lucine
  Lucinoma Dall, 1901 -- valid
  Lucinoma annulatum (Reeve, 1850) -- valid -- ringed lucine, western ringed lucina
  Lucinoma blakeanum (Bush, 1893) -- valid -- Blake lucine
  Lucinoma filosum (Stimpson, 1851) -- valid -- northeast lucine
  Lunatia catena (da Costa, 1778) -- invalid
  Lunatia immaculata Totten, 1835 -- invalid
  Lunatia lewisii (Gould, 1847) -- invalid
  Lunatia tenuis (Récluz, 1850) -- invalid
  Lunatia triseriata (Say, 1826) -- invalid
  Lussivolutopsius Kantor, 1983 -- valid
  Lussivolutopsius filosus (Dall, 1919) -- valid -- threaded whelk
  Luzonia Dall and E. A. Smith, 1890 -- valid
  Luzonia walleri (Bernard, 1989) -- valid -- short dipperclam
  Lymnaea Lamarck, 1799 -- valid
  Lymnaea atkaensis Dall, 1884 -- valid -- Frigid Lymnaea
  Lymnaea stagnalis (Linnaeus, 1758) -- valid -- swamp lymnaea
  Lymnaeidae Rafinesque, 1815 -- valid -- elegant pondsnails
  Lyogyrus Gill, 1863 -- valid
  Lyogyrus bakerianus (Pilsbry, 1917) -- valid -- Baker's Springsnail
  Lyogyrus browni (Carpenter, 1872) -- valid -- Slender Duskysnail
  Lyogyrus granum (Say, 1822) -- valid -- Squat Duskysnail
  Lyogyrus greggi (Pilsbry, 1935) -- invalid -- Rocky Mountain duskysnail
  Lyogyrus latus F. G. Thompson and Hershler, 1991 -- valid -- Cobble Sprite
  Lyogyrus pilsbryi (Walker, 1906) -- valid -- Lake Duskysnail
  Lyogyrus pupoideus (Gould, 1841) -- valid -- Pupa Duskysnail
  Lyogyrus retromargo (F. G. Thompson, 1968) -- valid -- Indented Duskysnail
  Lyogyrus walkeri (Pilsbry, 1898) -- valid -- Canadian Duskysnail
  Lyonsia Turton, 1822 -- valid
  Lyonsia arenosa (Moller, 1842) -- valid -- sandy lyonsia
  Lyonsia bracteata (Gould, 1850) -- valid -- scaly lyonsia
  Lyonsia californica Conrad, 1837 -- valid -- California lyonsia, island lyonsia
  Lyonsia floridana Conrad, 1849 -- valid -- Florida lyonsia
  Lyonsia granulifera A. E. Verrill and Bush, 1898 -- valid -- granulate lyonsia
  Lyonsia hyalina Conrad, 1831 -- valid -- glassy lyonsia
  Lyonsia striata (Montagu, 1815) -- valid -- striate lyonsia
  Lyonsiidae P. Fischer, 1887 -- valid
  Lyrodus Binney, 1870 -- valid
  Lyrodus bipartitus (Jeffreys, 1860) -- valid -- furrow shipworm
  Lyrodus floridanus (Bartsch, 1922) -- valid -- Florida shipworm
  Lyrodus pedicellatus (de Quatrefages, 1849) -- valid -- blacktip shipworm
  Lyrodus takanoshimensis (Roch, 1929) -- valid -- Takanoshima shipworm
  Lyropecten Conrad, 1862 -- valid
  Lyropecten kallinubilosus (Bayer, 1943) -- valid -- clouded scallop
  Macoma Leach, 1819 -- valid
  Macoma acolasta Dall, 1921 -- valid -- morsel macoma
  Macoma balthica (Linnaeus, 1758) -- valid -- Baltic macoma
  Macoma brevifrons (Say, 1834) -- valid -- short macoma
  Macoma brota Dall, 1916 -- valid -- heavy macoma
  Macoma calcarea (Gmelin, 1791) -- valid -- chalky macoma
  Macoma carlottensis Whiteaves, 1880 -- valid -- Charlotte macoma
  Macoma cerina C. B. Adams, 1845 -- valid -- waxy macoma
  Macoma constricta (Bruguiere, 1792) -- valid -- constricted macoma
  Macoma crassula (Deshayes, 1855) -- valid -- thick macoma
  Macoma dexioptera Baxter, 1977 -- valid -- rightwing macoma
  Macoma elimata Dunnill and Coan, 1968 -- valid -- file macoma, beveled macoma
  Macoma expansa Carpenter, 1864 -- valid -- expanded macoma
  Macoma extenuata Dall, 1900 -- valid -- slender macoma
  Macoma indentata Carpenter, 1864 -- valid -- indented macoma
  Macoma inquinata (Deshayes, 1855) -- valid -- stained macoma, pointed macoma
  Macoma lama Bartsch, 1929 -- valid -- Aleutian macoma
  Macoma limula Dall, 1895 -- valid -- little-file macoma
  Macoma lipara Dall, 1916 -- valid -- sleek macoma
  Macoma loveni (A. S. Jensen, 1905) -- valid -- loven macoma, inflated macoma
  Macoma middendorffi Dall, 1884 -- valid -- Middendorff macoma
  Macoma mitchelli Dall, 1895 -- valid -- mitchell macoma, Matagorda macoma
  Macoma moesta (Deshayes, 1855) -- valid -- flat macoma
  Macoma nasuta (Conrad, 1837) -- valid -- bent-nose macoma
  Macoma obliqua (J. Sowerby, 1817) -- valid -- oblique macoma, oval macoma
  Macoma phenax Dall, 1900 -- valid -- cheating macoma
  Macoma pulleyi Boyer, 1969 -- valid -- pulley macoma, delta macoma
  Macoma secta (Conrad, 1837) -- valid -- white-sand macoma
  Macoma tageliformis Dall, 1900 -- valid -- tagelus macoma
  Macoma tenta (Say, 1834) -- valid -- elongate macoma
  Macoma torelli (A. S. Jensen, 1905) -- valid -- triangular macoma
  Macoma yoldiformis Carpenter, 1864 -- valid -- yoldia macoma
  Macrarene Hertlein and Strong, 1951 -- valid
  Macrarene cookeana (Dall, 1918) -- valid
  Macrarene farallonensis (A. G. Smith, 1952) -- valid -- Farallon cyclostreme
  Macrocallista Meek, 1876 -- valid
  Macrocallista maculata (Linnaeus, 1758) -- valid -- calico clam
  Macrocallista nimbosa (Lightfoot, 1786) -- valid -- sunray venus
  Macrocypraea Schilder, 1930 -- valid
  Macrocypraea cervus (Linnaeus, 1771) -- valid -- Atlantic deer cowrie
  Macrocypraea zebra (Linnaeus, 1758) -- valid -- measled cowrie
  Macron H. Adams and A. Adams, 1853 -- valid
  Macron lividus (A. Adams, 1855) -- valid -- livid macron
  Mactra californica Conrad, 1837 -- invalid -- California surfclam
  Mactra fragilis Gmelin, 1791 -- invalid -- fragile surfclam
  Mactra nasuta Gould, 1851 -- invalid -- bent surfclam
  Mactrellona alata (Sprengler, 1802) -- valid -- winged surfclam
  Mactridae Lamarck, 1809 -- valid
  Mactromeris Conrad, 1868 -- valid
  Mactromeris catilliformis (Conrad, 1867) -- valid -- dish surfclam
  Mactromeris hemphillii (Dall, 1894) -- valid -- Hemphill surfclam
  Mactromeris polynyma (Stimpson, 1860) -- valid -- Arctic surfclam
  Mactrotoma Dall, 1894 -- valid
  Mactrotoma californica (Conrad, 1837) -- valid -- California surfclam
  Mactrotoma fragilis (Gmelin, 1791) -- valid -- fragile surfclam
  Mactrotoma nasuta (Gould, 1851) -- valid -- bent surfclam, ridged surfclam
  Magnipelta Pilsbry, 1953 -- valid
  Magnipelta mycophaga Pilsbry, 1953 -- valid -- spotted fungus slug, magnum mantleslug
  Malleidae Lamarck, 1818 -- valid
  Malletia Desmoulins, 1832 -- valid
  Malletia faba Dall, 1897 -- valid -- bean malletia
  Malletiidae H. and A. Adams, 1858 -- valid
  Malleus Lamarck, 1799 -- valid
  Malleus candeanus (d'Orbigny, 1842) -- valid -- Caribbean hammer-oyster
  Mangelia Risso, 1826 -- valid
  Mangelia aculea (Dall, 1919) -- valid
  Mangelia amatula (Dall, 1919) -- valid
  Mangelia astricta Reeve, 1846 -- valid
  Mangelia ceroplasta Bush, 1885 -- valid
  Mangelia cesta Dall, 1919 -- valid
  Mangelia constricta (Gabb, 1865) -- valid
  Mangelia densilineata (Dall, 1921) -- valid
  Mangelia hexagona Gabb, 1865 -- valid
  Mangelia hooveri Arnold, 1903 -- valid
  Mangelia louisa (Dall, 1919) -- valid
  Mangelia merita Hinds, 1843 -- valid
  Mangelia painei Arnold, 1903 -- valid
  Mangelia perattenuata Dall, 1905 -- valid
  Mangelia pomara (Dall, 1919) -- valid
  Mangelia victoriana (Dall, 1897) -- valid
  Manzanellidae Chronic, 1952 -- valid
  Manzonia Brusina, 1870 -- valid
  Manzonia aequisculpta (Keep, 1887) -- valid
  Manzonia almo (Bartsch, 1911) -- valid
  Manzonia cosmia (Bartsch, 1911) -- valid -- cosmic alvania
  Manzonia purpurea (Dall, 1871) -- valid -- purple alvania
  Margarites J. E. Gray, 1847 -- valid
  Margarites albolineatus (E. A. Smith, 1899) -- valid
  Margarites argentatus (Gould, 1841) -- valid
  Margarites beringensis (E. A. Smith, 1899) -- valid
  Margarites costalis (Gould, 1841) -- valid -- boreal rosy margarite
  Margarites costalis baxteri J. H. McLean, 1995 -- valid -- boreal rosy margarite
  Margarites costalis costalis (Gould, 1841) -- valid -- boreal rosy margarite
  Margarites ecarinatus (Dall, 1919) -- valid
  Margarites frigidus Dall, 1919 -- valid -- polar margarite
  Margarites giganteus (Leche, 1878) -- valid -- giant margarite
  Margarites groenlandicus (Gmelin, 1791) -- valid -- Greenland margarite
  Margarites helicinus (Phipps, 1774) -- valid -- spiral margarite
  Margarites hickmanae J. H. McLean, 1984 -- valid
  Margarites keepi A. G. Smith and M. Gordon, 1948 -- valid
  Margarites multilineatus (DeKay, 1843) -- valid -- many-lined margarite, many-line margarite
  Margarites ochotensis (Philippi, 1846) -- valid
  Margarites olivaceus (T. Brown, 1827) -- valid -- olive margarite
  Margarites pribiloffensis (Dall, 1919) -- valid
  Margarites pupillus (Gould, 1849) -- valid -- little margarite
  Margarites salmoneus (Carpenter, 1864) -- valid -- salmon margarite
  Margarites simbla Dall, 1913 -- valid -- beehive margarite
  Margarites smithi Bartsch, 1927 -- valid
  Margarites sordidus (Hancock, 1846) -- valid
  Margarites striatus (Leach, 1819) -- valid
  Margarites vahlii (Moller, 1842) -- valid
  Margarites vorticifer (Dall, 1873) -- valid -- vortex margarite
  Margaritifera Schumacher, 1816 -- valid
  Margaritifera falcata (Gould, 1850) -- valid -- Western pearlshell
  Margaritifera hembeli (Conrad, 1838) -- valid -- Louisiana pearlshell
  Margaritifera margaritifera (Linnaeus, 1758) -- valid -- eastern pearlshell
  Margaritifera marrianae R. I. Johnson, 1983 -- valid -- Alabama pearlshell
  Margaritiferidae Henderson, 1929 -- valid
  Marginella amabilis Redfield, 1852 -- invalid -- queen marginella
  Marginella apicina Menke, 1828 -- invalid -- common Atlantic marginella
  Marginella bella Conrad, 1868 -- invalid -- la belle marginella
  Marginella borealis (A. E. Verrill, 1884) -- invalid -- boreal marginella
  Marginella carnea (Storer, 1837) -- invalid -- orange marginella
  Marginella cassis Dall, 1889 -- invalid -- helmet marginella
  Marginella cineracea Dall, 1889 -- invalid -- gray marginella
  Marginella evelynae Bayer, 1943 -- invalid
  Marginella guttata (Dillwyn, 1817) -- invalid -- white-spot marginella
  Marginella hartleyanum Schwengel, 1941 -- invalid
  Marginella hematita Kiener, 1834 -- invalid -- carmine marginella
  Marginella idiochila Scwengel, 1943 -- invalid
  Marginella lavalleeana D'Orbigny, 1841 -- invalid -- snowflake marginella
  Marginella nobiliana Bayer, 1943 -- invalid -- courtly marginella
  Marginella roosevelti Bartsch and Rehder, 1939 -- invalid
  Marginella roscida Redfield, 1860 -- invalid -- seaboard marginella
  Marginellidae Fleming, 1828 -- valid
  Marginellopsis Bavay, 1911 -- invalid
  Marginellopsis serrei Bavay, 1911 -- invalid
  Maricopella Roth, 1996 -- valid
  Maricopella allynsmithi (Gregg and W. B. Miller, 1969) -- valid -- Squaw Park talussnail
  Marinula succinea (Pfeiffer, 1854) -- invalid
  Marionia Vayssiere, 1877 -- valid
  Marionia tedi Ev. Marcus, 1983 -- valid
  Marisa Gray, 1824 -- valid
  Marisa cornuarietis (Linnaeus, 1758) -- valid -- giant rams-horn, Goldenhorn Marisa
  Marsenina Gray, 1850 -- valid
  Marsenina ampla A. E. Verrill, 1880 -- valid -- great lamellaria
  Marsenina glabra (Couthouy, 1838) -- valid -- bald lamellaria
  Marsenina globosa L. M. Perry, 1939 -- valid -- rotund lamellaria
  Marsenina rhombica (Dall, 1871) -- valid -- rhombic lamellaria
  Marsenina stearnsii (Dall, 1871) -- valid
  Marseniopsis Bergh, 1886 -- valid
  Marseniopsis sharonae (Willett, 1939) -- valid
  Marshallora Bouchet, 1985 -- valid
  Marshallora nigrocincta (C. B. Adams, 1839) -- valid -- black-line triphora
  Martesia G. B. Sowerby I, 1824 -- valid
  Martesia cuneiformis (Say, 1822) -- valid -- wedge-shaped piddock, wedge piddock
  Martesia fragilis A. E. Verrill and Bush, 1890 -- valid -- fragile piddock
  Martesia striata (Linnaeus, 1758) -- valid -- striate piddock
  Mathilda Semper, 1865 -- valid
  Mathilda barbadensis Dall, 1889 -- valid -- Barbados mathilda
  Mathilda hendersoni Dall, 1927 -- valid
  Mathilda scitula Dall, 1889 -- valid
  Mathilda yucatecana (Dall, 1881) -- valid -- Yucatan mathilda
  Mathildidae Dall, 1889 -- valid
  Maxwellia Bailey, 1950 -- valid
  Maxwellia gemma (G. B. Sowerby II, 1879) -- valid -- gem murex
  Maxwellia santarosana (Dall, 1905) -- valid -- Santa Rosa murex
  Mazatlania Dall, 1913 -- valid
  Mazatlania cosentini (Philippi, 1836) -- valid
  Medionidus Simpson, 1900 -- valid
  Medionidus acutissimus (Lea, 1831) -- valid -- Alabama moccasinshell
  Medionidus conradicus (Lea, 1834) -- valid -- Cumberland moccasinshell
  Medionidus mcglameriae van der Schalie, 1939 -- invalid -- Tombigbee moccasinshell
  Medionidus parvulus (Lea, 1860) -- valid -- Coosa moccasinshell
  Medionidus penicillatus (Lea, 1857) -- valid -- Gulf moccasinshell
  Medionidus simpsonianus Walker, 1905 -- valid -- Ochlockonee moccasinshell
  Medionidus walkeri (S. H. Wright, 1897) -- valid -- Suwannee moccasinshell
  Megalomphalus Brusina, 1871 -- valid
  Megalomphalus adamsii (P. Fischer, 1857) -- valid
  Megalomphalus californicus (Dall, 1903) -- valid -- California macromphaline
  Megalomphalus floridanus (Moore, 1965) -- valid -- Florida macromphaline
  Megalomphalus palmalitoris (Pilsbry and McGinty, 1950) -- valid -- Palm Beach macromphaline
  Megalomphalus pierrot (Gardner, 1948) -- valid
  Megalomphalus schmiederi J. H. McLean, 1996 -- valid
  Megalonaias Utterback, 1915 -- valid
  Megalonaias boykiniana (Lea, 1840) -- invalid -- round washboard
  Megalonaias nervosa (Rafinesque, 1820) -- valid -- washboard
  Megapallifera Fairbanks, 1990 -- valid
  Megapallifera mutabilis (Hubricht, 1951) -- valid -- changeable mantleslug
  Megapallifera ragsdalei (Webb, 1950) -- valid -- Ozark mantleslug
  Megapallifera wetherbyi (W. G. Binney, 1874) -- valid -- blotchy mantleslug
  Megastraea J. H. McLean, 1970 -- valid
  Megastraea turbanica (Dall, 1910) -- valid
  Megastraea undosa (W. Wood, 1828) -- valid -- wavy turban
  Megasurcula Casey, 1904 -- valid
  Megasurcula carpenteriana (Gabb, 1865) -- valid
  Megasurcula remondii (Gabb, 1866) -- valid
  Megasurcula stearnsiana (Raymond, 1904) -- valid
  Megathura Pilsbry, 1890 -- valid
  Megathura crenulata (G. B. Sowerby I, 1825) -- valid -- giant keyhole limpet
  Megayoldia A. E. Verrill and Bush, 1897 -- valid
  Megayoldia martyria (Dall, 1897) -- valid -- oblique yoldia
  Megayoldia montereyensis (Dall, 1893) -- valid -- Monterey yoldia
  Megayoldia thraciaeformis (Storer, 1838) -- valid -- broad yoldia
  Megomphicidae H. B. Baker, 1930 -- valid
  Megomphix H. B. Baker, 1930 -- valid
  Megomphix californicus A. G. Smith, 1960 -- valid -- Natural Bridge megomphix
  Megomphix hemphilli (W. G. Binney, 1879) -- valid -- Oregon megomphix
  Megomphix lutarius H. B. Baker, 1932 -- valid -- umatilla megomphix
  Meiomenia M. P. Morse, 1979 -- valid
  Meiomenia arenicola Salvini-Plawen, 1985 -- valid -- Atlantic psammonworm
  Meiomenia swedmarki M. P. Morse, 1979 -- valid -- Pacific psammonworm
  Meiomeniidae -- valid
  Melampus Montfort, 1810 -- valid
  Melampus bidentatus Say, 1822 -- valid -- eastern melampus
  Melampus bullaoides (Montagu, 1808) -- valid -- bubble melampus
  Melampus coffeus (Linnaeus, 1758) -- valid -- coffee melampus
  Melampus floridanus Pfeiffer, 1856 -- valid -- Florida melampus
  Melampus morrisoni Martins, 1996 -- valid
  Melampus olivaceus Carpenter, 1856 -- valid -- California melampus
  Melanella Bowdich, 1822 -- valid
  Melanella berryi Bartsch, 1917 -- valid
  Melanella comoxensis Bartsch, 1917 -- valid
  Melanella compacta (Carpenter, 1866) -- valid
  Melanella conoidea (Kurtz and Stimpson, 1851) -- valid -- conoidal eulima
  Melanella delmontensis (A. G. Smith and M. Gordon, 1948) -- valid
  Melanella elongata Bucquoy, Dollfus and Dautzenberg, 1883 -- valid
  Melanella eulimoides (C. B. Adams, 1850) -- valid -- grooved eulima
  Melanella gracilis (C. B. Adams, 1850) -- valid
  Melanella jamaicensis (C. B. Adams, 1845) -- valid -- Jamaica eulima
  Melanella lastra Bartsch, 1917 -- valid
  Melanella micans (Carpenter, 1865) -- valid
  Melanella montereyensis Bartsch, 1917 -- valid -- Monterey eulima
  Melanella oldroydae Bartsch, 1917 -- valid
  Melanella orphanensis Clarke, 1974 -- valid
  Melanella peninsularis Bartsch, 1917 -- valid -- Baja eulima
  Melanella sarsi (Bush, 1909) -- valid
  Melanella tacomaensis Bartsch, 1917 -- valid -- Tacoma eulima
  Melanella thersites (Carpenter, 1864) -- valid
  Melaniella L. Pfeiffer, 1857 -- valid
  Melaniella gracillima (L. Pfeiffer, 1839) -- valid -- brown foxsnail
  Melanochlamys Cheesman, 1881 -- valid
  Melanochlamys diomedea (Bergh, 1894) -- valid -- albatross aglaja
  Melanoides Olivier, 1804 -- valid
  Melanoides tuberculatus (Muller, 1774) -- valid -- red-rim melania
  Melanoides turriculus (I. Lea, 1850) -- valid -- fawn melania
  Melibe Rang, 1829 -- valid
  Melibe leonina (Gould, 1852) -- valid -- lion nudibranch
  Melongena Schumacher, 1817 -- valid
  Melongena bicolor (Say, 1826) -- valid
  Melongena corona (Gmelin, 1791) -- valid -- crown conch
  Melongena corona corona (Gmelin, 1791) -- valid -- crown conch
  Melongena corona johnstonei Clench and Turner, 1956 -- valid -- crown conch
  Melongena sprucecreekensis Tucker, 1994 -- valid
  Melongenidae Gill, 1871 -- valid
  Mendicula Iredale, 1924 -- valid
  Mendicula ferruginosa (Forbes, 1844) -- valid -- rusty axinopsid
  Menestho Moller, 1842 -- valid
  Menestho albula (Fabricius, 1780) -- valid
  Menetus H. Adams and A. Adams, 1855 -- valid
  Menetus floridensis F. C. Baker, 1945 -- invalid -- penny sprite
  Menetus opercularis (Gould, 1847) -- valid -- Button Sprite
  Mercenaria Schumacher, 1817 -- valid
  Mercenaria campechiensis (Gmelin, 1791) -- valid -- southern quahog
  Mercenaria mercenaria (Linnaeus, 1758) -- valid -- northern quahog
  Mesodesma Deshayes, 1832 -- valid
  Mesodesma arctatum (Conrad, 1830) -- valid -- Arctic wedgeclam
  Mesodesma deauratum (Turton, 1822) -- valid -- gilded wedgeclam
  Mesodesmatidae Gray, 1839 -- valid
  Mesodon Rafinesque, 1821 -- valid
  Mesodon altivagus (Pilsbry, 1900) -- valid -- wandering globe
  Mesodon andrewsae W. G. Binney, 1879 -- valid -- balsam globe
  Mesodon appressus (Say, 1821) -- invalid -- flat bladetooth
  Mesodon approximans (G. H. Clapp, 1905) -- invalid -- tight-gapped shagreen
  Mesodon archeri Pilsbry, 1940 -- invalid -- ocoee covert
  Mesodon binneyanus (Pilsbry, 1899) -- invalid -- half-lidded oval
  Mesodon chilhoweensis (J. Lewis, 1870) -- invalid -- queen crater
  Mesodon christyi (Bland, 1860) -- invalid -- glossy covert
  Mesodon clarki (I. Lea, 1858) -- invalid -- noonday snail
  Mesodon clarki clarki (I. Lea, 1858) -- invalid -- dwarf proud globe
  Mesodon clarki nantahala (Clench, 1933) -- invalid -- noonday globe
  Mesodon clausus (Say, 1821) -- valid -- yellow globelet
  Mesodon clenchi (Rehder, 1932) -- invalid -- Calico Rock oval
  Mesodon downieanus (Bland, 1861) -- invalid -- dwarf globelet
  Mesodon edentatus (Sampson, 1889) -- invalid -- smooth-lip shagreen
  Mesodon elevatus (Say, 1821) -- valid -- proud globe
  Mesodon ferrissi (Pilsbry, 1897) -- invalid -- Smoky Mountain covert
  Mesodon indianorum (Pilsbry, 1899) -- invalid -- lidded oval
  Mesodon inflectus (Say, 1821) -- invalid -- shagreen
  Mesodon jonesianus (Archer, 1938) -- invalid -- big-tooth covert
  Mesodon kalmianus Hubricht, 1965 -- invalid -- brown globelet
  Mesodon kiowaensis (Simpson, 1888) -- invalid -- drywoods oval
  Mesodon leatherwoodi Pratt, 1971 -- invalid -- Pedernales oval
  Mesodon magazinensis (Pilsbry and Ferriss, 1907) -- invalid -- Magazine Mountain shagreen
  Mesodon mitchellianus (I. Lea, 1839) -- valid -- sealed globelet
  Mesodon normalis (Pilsbry, 1900) -- valid -- grand globe
  Mesodon orestes Hubricht, 1975 -- invalid -- engraved covert
  Mesodon panselenus Hubricht, 1976 -- invalid -- Virginia bladetooth
  Mesodon pennsylvanicus (Green, 1827) -- invalid -- proud globelet
  Mesodon perigraptus Pilsbry, 1894 -- invalid -- engraved bladetooth
  Mesodon roemeri (Pfeiffer, 1848) -- invalid -- Texas oval
  Mesodon rugeli (Shuttleworth, 1852) -- invalid -- deep-tooth shagreen
  Mesodon sanus (Clench and Archer, 1933) -- valid -- squat globelet
  Mesodon sargentianus (C. W. Johnson and Pilsbry, 1892) -- invalid -- grand bladetooth
  Mesodon sayanus (Pilsbry, 1906) -- invalid -- spike-lip crater
  Mesodon smithi (G. H. Clapp, 1905) -- invalid -- Alabama shagreen
  Mesodon subpalliatus (Pilsbry, 1893) -- invalid -- velvet covert
  Mesodon thyroidus (Say, 1816) -- valid -- white-lip globe
  Mesodon trossulus Hubricht, 1966 -- valid -- dandy globelet
  Mesodon wetherbyi (Bland, 1873) -- invalid -- clifty covert
  Mesodon wheatleyi (Bland, 1860) -- invalid -- cinnamon covert
  Mesodon zaletus (A. Binney, 1837) -- valid -- toothed globe
  Mesomphix Rafinesque, 1819 -- valid
  Mesomphix andrewsae (Pilsbry, 1895) -- valid -- mountain button
  Mesomphix anurus Hubricht, 1962 -- valid -- frog button
  Mesomphix capnodes (W. G. Binney, 1857) -- valid -- dusky button
  Mesomphix cupreus (Rafinesque, 1831) -- valid -- copper button
  Mesomphix friabilis (W. G. Binney, 1857) -- valid -- brittle button
  Mesomphix globosus (MacMillan, 1940) -- valid -- globose button
  Mesomphix inornatus (Say, 1821) -- valid -- plain button
  Mesomphix latior (Pilsbry, 1900) -- valid -- broad button
  Mesomphix perfragilis (Wetherby, 1894) -- valid -- fragile button
  Mesomphix perlaevis (Pilsbry, 1900) -- valid -- smooth button
  Mesomphix pilsbryi (G. H. Clapp, 1904) -- valid -- striate button
  Mesomphix rugeli (W. G. Binney, 1879) -- valid -- wrinkled button
  Mesomphix subplanus (A. Binney, 1842) -- valid -- flat button
  Mesomphix vulgatus H. B. Baker, 1933 -- valid -- common button
  Metachaetoderma Thiele, 1913 -- valid
  Metastoma Strebel and Pfeffer, 1880 -- valid
  Metastoma roemeri (Pfeiffer, 1848) -- valid -- distorted metastoma
  Metaxia di Monterosato, 1884 -- valid
  Metaxia convexa (Carpenter, 1856) -- valid
  Metaxia rugulosa (C. B. Adams, 1850) -- valid
  Metaxia taeniolata (Dall, 1889) -- valid
  Metula H. Adams and A. Adams, 1853 -- valid
  Metula significans (Rehder, 1943) -- valid
  Metzgeria Norman, 1879 -- valid
  Metzgeria californica Dall, 1903 -- valid -- California false spindle
  Metzgeria montereyana A. G. Smith and M. Gordon, 1948 -- valid -- Monterey false spindle
  Mexichromis Bertsch, 1977 -- valid
  Mexichromis porterae (Cockerell, 1901) -- valid
  Micichiton Sirenko, 1975 -- invalid
  Micichiton grandispina Sirenko, 1975 -- invalid
  Micrarionta Ancey, 1880 -- valid
  Micrarionta beatula Cockerell, 1929 -- valid -- Avalon islandsnail
  Micrarionta facta (Newcomb, 1864) -- valid -- Santa Barbara islandsnail
  Micrarionta feralis (Hemphill, 1901) -- valid -- San Nicolas islandsnail
  Micrarionta gabbii (Newcomb, 1864) -- valid -- san clemente islandsnail
  Micrarionta opuntia Roth, 1975 -- valid -- pricklypear islandsnail
  Micrarionta rufocincta (Newcomb, 1864) -- valid -- Santa Catalina islandsnail
  Microceramus Pilsbry and Vanatta, 1898 -- valid
  Microceramus pontificus (Gould, 1848) -- valid -- pontiff urocoptid
  Microceramus texanus (Pilsbry, 1898) -- valid -- Texas urocoptid
  Microeulima Waren, 1992 -- valid
  Microeulima hemphillii (Dall, 1884) -- valid -- brown eulima
  Microgaza Dall, 1881 -- valid
  Microgaza rotella Dall, 1881 -- valid -- dwarf gaza
  Microgaza rotella inornata Quinn, 1979 -- valid -- dwarf gaza
  Microgaza rotella rotella Dall, 1881 -- valid -- dwarf gaza
  Microglyphis Dall, 1902 -- valid
  Microglyphis brevicula (Dall, 1902) -- valid -- short baby-bubble
  Microglyphis estuarina (Dall, 1908) -- valid -- estuarine baby-bubble
  Microhedylidae Odhner, 1937 -- invalid
  Micromelo Pilsbry, 1895 -- valid
  Micromelo undatus (Bruguiere, 1792) -- valid -- miniature melo
  Micromenetus F. C. Baker, 1945 -- valid
  Micromenetus alabamensis (Pilsbry, 1895) -- invalid -- marsh sprite
  Micromenetus brogniartianus (Lea, 1842) -- valid -- Disc Sprite, Marsh Sprite
  Micromenetus dilatatus (Gould, 1841) -- valid -- Bugle Sprite
  Micromenetus floridensis (F. C. Baker, 1945) -- valid -- Penny Sprite
  Micromenetus sampsoni (Ancey, 1885) -- valid -- Sampson Sprite
  Microphysula Cockerell, 1926 -- valid
  Microphysula cookei (Pilsbry, 1922) -- valid -- Vancouver snail
  Microphysula ingersolli (Bland, 1875) -- valid -- spruce snail
  Microstelma A. Adams, 1863 -- valid
  Microstelma vestale (Rehder, 1943) -- valid
  Microtralia Dall, 1894 -- valid
  Microtralia occidentalis (Pfeiffer, 1854) -- valid
  Microvoluta Angas, 1877 -- valid
  Microvoluta blakeana (Dall, 1889) -- valid
  Miesea Er. Marcus, 1961 -- valid
  Miesea evelinae (Er. Marcus, 1957) -- valid
  Milacidae Ellis, 1926 -- valid
  Milax Gray, 1855 -- valid
  Milax gagates (Draparnaud, 1801) -- valid -- jet greenhouse slug, greenhouse slug
  Millerelix Pratt, 1981 -- valid
  Millerelix deltoidea (Simpson, 1889) -- valid -- Oklahoma liptooth
  Millerelix dorfeuilliana (I. Lea, 1838) -- valid -- oakwood liptooth
  Millerelix fatigiata (Say, 1829) -- valid -- bluegrass liptooth
  Millerelix gracilis (Hubricht, 1961) -- valid -- Edwards Plateau liptooth
  Millerelix jacksoni (Bland, 1866) -- valid -- Ozark liptooth
  Millerelix lithica (Hubricht, 1961) -- valid -- stone liptooth
  Millerelix mooreana (W. G. Binney, 1858) -- valid -- grassland liptooth
  Millerelix peregrina (Rehder, 1932) -- valid -- White liptooth
  Millerelix plicata (Say, 1821) -- valid -- Cumberland liptooth
  Millerelix simpsoni (Pilsbry and Ferriss, 1907) -- valid -- Wyandotte liptooth
  Millerelix troostiana (I. Lea, 1839) -- valid -- Nashville liptooth
  Milneria Dall, 1881 -- valid
  Milneria kelseyi Dall, 1916 -- valid -- kelsey pouch-clam, Kelsey pouchclam
  Milneria minima (Dall, 1871) -- valid -- tiny pouch-clam, tiny pouchclam
  Miodontiscus Dall, 1903 -- valid
  Miodontiscus prolongatus (Carpenter, 1864) -- valid -- elongate carditid
  Mirachelus Woodring, 1928 -- valid
  Mirachelus clinocnemus Quinn, 1979 -- valid -- stooped mirachelus
  Mirachelus corbis (Dall, 1889) -- valid -- basket mirachelus
  Miraclathurella Woodring, 1928 -- valid
  Miraclathurella herminea (Bartsch, 1934) -- valid
  Mitra Roding, 1798 -- valid
  Mitra barbadensis (Gmelin, 1791) -- valid -- Barbados miter
  Mitra florida Gould, 1856 -- valid -- Florida miter
  Mitra fultoni E. A. Smith, 1892 -- valid -- pitted miter
  Mitra idae Melvill, 1893 -- valid -- half-pitted miter
  Mitra nodulosa (Gmelin, 1791) -- valid -- beaded miter
  Mitra pallida Nowell-Usticke, 1959 -- valid
  Mitra semiferruginea Reeve, 1845 -- valid
  Mitra straminea A. Adams, 1853 -- valid -- Gulf Stream miter
  Mitra swainsonii Broderip, 1836 -- valid -- Antillean miter
  Mitra swainsonii antillensis Dall, 1889 -- valid -- Antillean miter
  Mitrella Risso, 1826 -- valid
  Mitrella callimorpha (Dall, 1919) -- valid
  Mitrella clementensis (Bartsch, 1927) -- valid -- San Clemente dovesnail
  Mitrella dichroa (G. B. Sowerby I, 1844) -- valid -- argus dovesnail
  Mitrella dicomata (Dall, 1889) -- valid
  Mitrella ocellata (Gmelin, 1791) -- valid -- white-spot dovesnail
  Mitridae Swainson, 1931 -- valid
  Mitrolumna Bucquoy, Dautzenberg and Dollfus, 1883 -- valid
  Mitrolumna biplicata (Dall, 1889) -- valid
  Mitromorpha Carpenter, 1865 -- valid
  Mitromorpha carpenteri Gilbert, 1954 -- valid
  Modiolus Lamarck, 1799 -- valid
  Modiolus americanus (Leach, 1815) -- valid -- American horsemussel
  Modiolus capax (Conrad, 1837) -- valid -- fat horsemussel
  Modiolus carpenteri Soot-Ryen, 1963 -- valid -- California horsemussel
  Modiolus modiolus (Linnaeus, 1758) -- valid -- northern horsemussel
  Modiolus neglectus Soot-Ryen, 1955 -- valid -- neglected horsemussel
  Modiolus rectus (Conrad, 1837) -- valid -- straight horsemussel
  Modiolus sacculifer (S. S. Berry, 1953) -- valid -- bag horsemussel
  Modulidae P. Fischer, 1884 -- valid
  Modulus Gray, 1842 -- valid
  Modulus calusa Petuch, 1988 -- valid
  Modulus floridanus Conrad, 1869 -- valid
  Modulus kaicherae Petuch, 1987 -- valid
  Modulus lindae Petuch, 1987 -- valid
  Modulus modulus (Linnaeus, 1758) -- valid -- buttonsnail
  Modulus pacei Petuch, 1987 -- valid
  Moelleria Jeffreys, 1865 -- valid
  Moelleria costulata (Moller, 1842) -- valid -- ribbed moelleria
  Mohavelix Berry, 1943 -- valid
  Mohavelix micrometalleus (S. S. Berry, 1930) -- valid -- el paso shoulderband
  Mohnia Friele, 1879 -- valid
  Mohnia parva (A. E. Verrill and S. Smith, 1882) -- valid
  Mohnia simplex (A. E. Verrill, 1884) -- valid
  Mollusca -- valid -- mollusques, molusco, molluscs, mollusks
  Monacha Fitzinger, 1833 -- valid
  Monacha cantiana (Montagu, 1803) -- valid -- Kentish gardensnail
  Monadenia Pilsbry, 1895 -- valid
  Monadenia callipeplus S. S. Berry, 1940 -- valid -- downy sideband
  Monadenia chaceana S. S. Berry, 1940 -- valid -- Siskiyou sideband
  Monadenia churchi Hanna and A. G. Smith, 1933 -- valid -- Klamath sideband
  Monadenia circumcarinata (Stearns, 1879) -- valid -- keeled sideband
  Monadenia cristulata S. S. Berry, 1940 -- valid -- crested sideband
  Monadenia fidelis (J. E. Gray, 1834) -- valid -- Pacific sideband
  Monadenia infumata (Gould, 1855) -- valid -- redwood sideband
  Monadenia marmarotis S. S. Berry, 1940 -- valid
  Monadenia mormonum (Pfeiffer, 1857) -- valid -- Sierra sideband
  Monadenia rotifer S. S. Berry, 1940 -- valid
  Monadenia scottiana S. S. Berry, 1940 -- valid -- Scott sideband
  Monadenia setosa Talmadge, 1952 -- valid -- Trinity bristlesnail
  Monadenia troglodytes Hanna and A. G. Smith, 1933 -- valid -- Shasta sideband
  Monadenia tuolumneana S. S. Berry, 1955 -- valid -- tuolumne sideband
  Monadenia yosemitensis (Lowe, 1916) -- valid -- Mariposa sideband
  Monoplacophora -- valid -- monoplacophorans
  Monostiolum Dall, 1904 -- valid
  Monostiolum tesselatum (Reeve, 1844) -- valid
  Montacuta Turton, 1822 -- valid
  Montacuta percompressa Dall, 1899 -- valid -- much-compressed montacutid
  Mopalia Gray, 1847 -- valid
  Mopalia acuta (Carpenter, 1855) -- valid
  Mopalia ciliata (G. B. Sowerby II, 1840) -- valid
  Mopalia cirrata S. S. Berry, 1919 -- valid
  Mopalia cithara S. S. Berry, 1951 -- invalid
  Mopalia egretta S. S. Berry, 1919 -- valid
  Mopalia ferreirai R. N. Clark, 1991 -- valid
  Mopalia hindsii (Reeve, 1847) -- valid
  Mopalia imporcata Carpenter, 1864 -- valid
  Mopalia laevior Pilsbry, 1918 -- valid
  Mopalia lignosa (Gould, 1846) -- valid
  Mopalia lionotus Pilsbry, 1918 -- valid
  Mopalia lowei Pilsbry, 1918 -- valid
  Mopalia muscosa (Gould, 1846) -- valid
  Mopalia phorminx S. S. Berry, 1919 -- valid
  Mopalia porifera Pilsbry, 1893 -- valid
  Mopalia recurvans Barnawell, 1960 -- valid
  Mopalia sinuata Carpenter, 1864 -- valid
  Mopalia spectabilis G. I. M. Cowan and I. M. Cowan, 1977 -- valid
  Mopalia swanii Carpenter, 1864 -- valid
  Mopaliidae Dall, 1889 -- valid
  Morum Roding, 1798 -- valid
  Morum dennisoni (Reeve, 1842) -- valid -- Dennison morum
  Morum lamarcki (Deshayes, 1844) -- valid -- rose-mouth morum
  Morum oniscus (Linnaeus, 1767) -- valid -- Atlantic morum
  Mourgona Er. Marcus and Ev. Marcus, 1970 -- valid
  Mourgona germaineae Er. Marcus and Ev. Marcus, 1970 -- valid
  Mulinia Gray, 1837 -- valid
  Mulinia cleryana (d'Orbigny, 1846) -- valid -- Clery surfclam
  Mulinia lateralis (Say, 1822) -- valid -- dwarf surfclam
  Murchisonella Morch, 1875 -- valid
  Murchisonella tampaensis (Bartsch, 1947) -- valid -- Tampa aclis
  Murex anniae M. Smith, 1940 -- invalid
  Murex bellegladeensis Vokes, 1963 -- invalid -- belleglade murex
  Murex cabritii Bernardi, 1859 -- invalid
  Murex florifer dilectus (A. Adams, 1855) -- invalid
  Murex recurvirostris rubidus F. C. Baker, 1897 -- invalid -- rose murex
  Murex rubidus F. C. Baker, 1897 -- invalid
  Murex tryoni Hidalgo In Tryon, 1880 -- invalid
  Murexiella Clench and Perez Farfante, 1945 -- valid
  Murexiella glypta (M. Smith, 1938) -- valid -- carved murex
  Murexiella hidalgoi (Crosse, 1869) -- valid
  Murexiella kalafuti Petuch, 1987 -- valid
  Murexiella levicula (Dall, 1889) -- valid -- lightweight murex
  Murexiella macgintyi (M. Smith, 1938) -- valid
  Murexiella taylorae Petuch, 1987 -- valid
  Murexsul Iredale, 1915 -- valid
  Murexsul emipowlusi (Abbott, 1954) -- valid
  Muricantharus Hertlein and Strong, 1971 -- valid
  Muricantharus harasewychi Petuch, 1987 -- valid
  Muricanthus fulvescens (G. B. Sowerby II, 1834) -- invalid -- giant eastern murex
  Muricidae Rafinesque, 1815 -- valid
  Muricopsis Bucquoy, Dautzenberg and Dollfus, 1882 -- valid
  Muricopsis caribbaea (Bartsch and Rehder, 1939) -- valid
  Musculista Yamamoto and Habe, 1958 -- valid
  Musculista senhousia (Benson, 1842) -- valid -- senhouse mussel, green mussel
  Musculium Link, 1807 -- valid
  Musculium lacustre (Muller, 1774) -- valid -- lake fingernailclam
  Musculium partumeium (Say, 1822) -- valid -- swamp fingernailclam
  Musculium securis (Prime, 1852) -- valid -- pond fingernailclam
  Musculium transversum (Say, 1829) -- valid -- long fingernailclam
  Musculus Roding, 1798 -- valid
  Musculus discors (Linnaeus, 1767) -- valid -- discordant mussel
  Musculus glacialis (Leche, 1883) -- valid -- corrugate mussel
  Musculus lateralis (Say, 1822) -- valid -- lateral mussel
  Musculus marmoratus (Forbes, 1838) -- valid -- spotted mussel
  Musculus niger (J. E. Gray, 1824) -- valid -- black mussel
  Musculus phenax (Dall, 1915) -- valid
  Musculus pygmaeus Glynn, 1964 -- valid -- pygmy mussel
  Musculus taylori (Dall, 1897) -- valid -- taylor mussel
  Mya Linnaeus, 1758 -- valid
  Mya arenaria Linnaeus, 1758 -- valid -- softshell clam, softshell
  Mya baxteri Coan and Scott, 1997 -- valid -- deep softshell
  Mya pseudoarenaria Schlesch, 1931 -- valid -- false softshell clam, false softshell
  Mya truncata Linnaeus, 1758 -- valid -- truncate softshell clam, truncate softshell
  Myidae Lamarck, 1809 -- valid
  Myoida Goldfuss, 1820 -- invalid
  Myonera Dall, 1886 -- valid
  Myonera lamellifera (Dall, 1881) -- valid -- shingled myoneria, shingled myonera
  Myosotella di Monterosato, 1906 -- valid
  Myosotella myosotis (Draparnaud, 1801) -- valid
  Myotophallus Pilsbry, 1939 -- valid
  Myotophallus rooseveltianus (S. S. Berry, 1917) -- valid -- Roosevelt talussnail
  Myrtea Turton, 1822 -- valid
  Myrtea compressa (Dall, 1881) -- valid -- compressed lucine
  Myrtea lens (A. E. Verrill and S. Smith, 1880) -- valid -- alens lucine, lens lucine
  Myrtea sagrinata (Dall, 1886) -- valid -- arrow lucine
  Mysella Angas, 1877 -- valid
  Mysella casta (A. E. Verrill and Bush, 1898) -- valid -- pure mysella
  Mysella moelleri (Morch, 1875) -- valid -- moeller mysella, dirty mysella
  Mysella ovata (Jeffreys, 1881) -- valid -- ovate mysella
  Mysella pedroana Dall, 1899 -- valid -- San Pedro mysella
  Mysella planata (Krause, 1885) -- valid -- flat mysella
  Mysella planulata (Stimpson, 1851) -- valid -- plate mysella
  Mysella striatula A. E. Verrill and Bush, 1898 -- valid -- scratched mysella
  Mysella triquetra (A. E. Verrill and Bush, 1898) -- valid -- triangular mysella
  Mysouffa Ev. Marcus, 1974 -- valid
  Mysouffa cumingii (A. Adams, 1855) -- valid
  Mytilidae Rafinesque, 1815 -- valid
  Mytilimeria Conrad, 1837 -- valid
  Mytilimeria nuttalli Conrad, 1837 -- valid -- bladderclam
  Mytiloida Ferussac, 1822 -- invalid
  Mytilopsis Conrad, 1857 -- valid
  Mytilopsis leucophaeata (Conrad, 1831) -- valid -- dark falsemussel
  Mytilopsis sallei (Recluz, 1849) -- valid -- Santo Domingo falsemussel
  Mytilus Linnaeus, 1758 -- valid
  Mytilus californianus Conrad, 1837 -- valid -- California mussel
  Mytilus edulis Linnaeus, 1758 -- valid -- edible blue mussel, blue mussel
  Mytilus galloprovincialis Lamarck, 1819 -- valid -- Mediterranean mussel
  Mytilus trossulus Gould, 1850 -- valid -- foolish mussel
  Naesiotus Albers, 1850 -- valid
  Naesiotus christenseni (W. B. Miller and Reeder, 1984) -- valid -- Santa Rita rabdotus
  Naesiotus nigromontanus (Dall, 1897) -- valid -- Black Mountain rabdotus
  Nannodiella Dall, 1919 -- valid
  Nannodiella oxia (Bush, 1885) -- valid
  Nannodiella vespuciana (d'Orbigny, 1842) -- valid
  Nanobalcis Waren and Mifsud, 1990 -- valid
  Nanobalcis worsfoldi Waren, 1990 -- valid
  Nassa obsoleta Say, 1822 -- invalid
  Nassariidae Iredale, 1916 -- valid
  Nassarina Dall, 1889 -- valid
  Nassarina bushiae (Dall, 1889) -- valid
  Nassarina glypta (Bush, 1885) -- valid -- engraved dovesnail
  Nassarina metabrunnea Dall and Simpson, 1901 -- valid
  Nassarina penicillata (Carpenter, 1864) -- valid -- penciled dovesnail
  Nassarius Dumeril, 1806 -- valid
  Nassarius acutus (Say, 1822) -- valid -- sharp nassa
  Nassarius albus (Say, 1826) -- valid -- antilles nassa, white nassa
  Nassarius antillarum (d'Orbigny, 1842) -- valid -- Antilles nassa
  Nassarius consensus (Ravenel, 1861) -- valid -- striate nassa
  Nassarius delosi (Woodring, 1946) -- valid
  Nassarius fossatus (Gould, 1850) -- valid -- channeled nassa
  Nassarius fraterculus (Dunker, 1860) -- valid -- Japanese nassa
  Nassarius hotessieri (d'Orbigny, 1845) -- valid -- miniature nassa
  Nassarius insculptus (Carpenter, 1864) -- valid -- smooth western nassa
  Nassarius mendicus (Gould, 1850) -- valid -- lean western nassa
  Nassarius mendicus cooperi (Forbes, 1850) -- invalid -- lean nassa
  Nassarius obsoletus (Say, 1822) -- valid -- eastern mudsnail
  Nassarius perpinguis (Hinds, 1844) -- valid -- fat western nassa
  Nassarius polygonatus (Lamarck, 1822) -- valid
  Nassarius polygonatus cinisculus (Reeve, 1853) -- invalid -- black-spot nassa
  Nassarius polygonatus polygonatus (Lamarck, 1822) -- invalid
  Nassarius rhinetes S. S. Berry, 1953 -- valid -- California nassa
  Nassarius tegula (Reeve, 1853) -- invalid -- western mud nassa
  Nassarius tiarula (Kiener, 1841) -- valid -- western mud nassa
  Nassarius trivittatus (Say, 1822) -- valid -- threeline mudsnail
  Nassarius vibex (Say, 1822) -- valid -- bruised nassa
  Natica Scoploi, 1777 -- valid
  Natica affinis Gmelin, 1791 -- invalid
  Natica aleutica Dall, 1919 -- invalid
  Natica canrena (Linnaeus, 1758) -- invalid -- colorful moonsnail
  Natica castrensis Dall, 1889 -- valid -- netted moonsnail
  Natica clausa Broderip & Sowerby G.B. I, 1829 -- invalid -- arctic moonsnail
  Natica helicoides Johnston, 1835 -- invalid
  Natica janthostoma Deshayes, 1839 -- invalid -- purplemouth moonsnail
  Natica livida Pfeiffer, 1840 -- valid -- livid moonsnail
  Natica marochiensis (Gmelin, 1791) -- valid -- Morocco moonsnail
  Natica russa Gould, 1859 -- invalid
  Natica sagraiana D'Orbigny, 1842 -- valid -- lined moonsnail
  Natica tedbayeri Rehder, 1986 -- valid
  Naticarius Duméril, 1806 -- valid
  Naticarius canrena (Linnaeus, 1758) -- valid -- colorful moonsnail
  Naticarius verae Rehder, 1947 -- valid
  Naticidae Guilding, 1834 -- valid
  Navanax Pilsbry, 1895 -- valid
  Navanax aenigmaticus (Bergh, 1893) -- valid -- mysterious aglaja
  Navanax inermis (J. G. Cooper, 1863) -- valid -- California aglaja
  Navanax polyalphos (Gosliner and Williams, 1972) -- valid
  Neadmete Habe, 1961 -- valid
  Neadmete modesta (Carpenter, 1864) -- valid -- modest admete
  Neaeromya Gabe, 1873 -- valid
  Neaeromya compressa (Dall, 1899) -- valid -- compressed montacutid
  Neaeromya rugifera (Carpenter, 1864) -- valid -- wrinkled montacutid
  Nearctula Sterki, 1892 -- valid
  Nearctula rowellii (Newcomb, 1860) -- valid -- ribbed vertigo
  Nemocardium Meek, 1876 -- valid
  Nemocardium centifilosum (Carpenter, 1864) -- valid -- hundred-line cockle
  Nemocardium peramabile (Dall, 1881) -- valid -- lovely micro-cockle
  Nemocardium tinctum (Dall, 1881) -- valid -- dyed micro-cockle
  Nemocardium transversum Rehder and Abbott, 1951 -- valid -- atransverse micro-cockle, transverse micro-cockle
  Neoberingius Habe and Ito, 1965 -- valid
  Neoberingius frielei (Dall, 1895) -- valid
  Neogastropoda -- valid
  Neohelix Ihering, 1892 -- valid
  Neohelix albolabris (Say, 1817) -- valid -- whitelip
  Neohelix alleni (Sampson, 1883) -- valid -- western whitelip
  Neohelix dentifera (A. Binney, 1837) -- valid -- big-tooth whitelip
  Neohelix divesta (Gould, 1848) -- valid -- Ozark whitelip
  Neohelix lioderma (Pilsbry, 1902) -- valid -- Tulsa whitelip
  Neohelix major (A. Binney, 1837) -- valid -- southeastern whitelip
  Neohelix solemi Emberton, 1988 -- valid -- coastal whitelip
  Neoloricata Bergenhayn, 1955 -- invalid -- chitons, chitons, oscabrions
  Neomeniomorpha -- invalid
  Neoplanorbis Pilsbry, 1906 -- valid
  Neoplanorbis carinatus Walker, 1908 -- valid -- Carinate Flat-top Snail
  Neoplanorbis smithi Walker, 1908 -- valid -- Angled Flat-top Snail
  Neoplanorbis tantillus Pilsbry, 1906 -- valid -- Little Flat-top Snail
  Neoplanorbis umbilicatus Walker, 1908 -- valid -- Umbilicate Flat-top Snail
  Neopycnodonte Stenzel, 1971 -- valid
  Neopycnodonte cochlear (Poli, 1795) -- valid -- deepsea oyster
  Neosimnia P. Fischer, 1884 -- valid
  Neosimnia advena (Cate, 1978) -- valid
  Neosimnia aequalis (G. B. Sowerby II, 1832) -- valid
  Neosimnia avena (G. B. Sowerby II, 1832) -- valid
  Neosimnia avena ruthturnerae Cate, 1973 -- valid
  Neosimnia barbarensis (Dall, 1892) -- valid -- Santa Barbara simnia
  Neosimnia bellamaris S. S. Berry, 1946 -- valid -- Pacific simnia
  Neosimnia bijuri (Cate, 1976) -- valid
  Neosimnia loebbeckeana (Weinkauff, 1881) -- valid
  Neosimnia spelta Linnaeus, 1758 -- valid -- Keys simnia
  Neosimnia spelta capitia Cate, 1973 -- valid -- Keys simnia
  Neotaenioglossa -- invalid
  Neotrapezium Habe, 1951 -- valid
  Neotrapezium liratum (Reeve, 1843) -- valid -- quadrate trapezium
  Nepotilla Hedley, 1918 -- valid
  Nepotilla amoena (G. O. Sars, 1878) -- valid
  Neptunea amianta (Dall, 1890) -- valid
  Neptunea beringiana (Middendorff, 1848) -- valid
  Neptunea borealis (Philippi, 1850) -- invalid
  Neptunea brevicauda (Deshayes, 1832) -- valid -- thick-ribbed whelk
  Neptunea communis (Middendorff, 1848) -- valid
  Neptunea decemcostata (Say, 1826) -- invalid -- wrinkle whelk
  Neptunea despecta (Linnaeus, 1758) -- valid
  Neptunea eucosmia (Dall, 1891) -- invalid -- corded whelk
  Neptunea heros (J. E. Gray, 1850) -- valid
  Neptunea lyrata (Gmelin, 1791) -- valid -- lyre whelk
  Neptunea lyrata decemcostata (Say, 1826) -- valid -- wrinkle whelk
  Neptunea lyrata lyrata (Gmelin, 1791) -- valid -- lyre whelk
  Neptunea lyrata turnerae Clarke, 1956 -- valid
  Neptunea magna (Dall, 1895) -- invalid -- helmet whelk
  Neptunea middendorffiana MacGinitie, 1959 -- valid
  Neptunea oncodes (Dall, 1907) -- valid
  Neptunea phoenicea (Dall, 1891) -- valid
  Neptunea pribiloffensis (Dall, 1919) -- valid -- Pribilof whelk
  Neptunea smirnia (Dall, 1919) -- valid -- smirnia whelk
  Neptunea stilesi A. G. Smith, 1968 -- invalid -- inflated whelk
  Neptunea tabulata (Baird, 1863) -- valid -- tabled whelk
  Neptunea varicifera (Dall, 1907) -- valid
  Neptunea ventricosa (Gmelin, 1791) -- valid -- fat whelk
  Neptunea vinosa (Dall, 1919) -- valid -- wine whelk
  Nerita Linnaeus, 1758 -- valid
  Nerita fulgurans Gmelin, 1791 -- valid -- Antillean nerite
  Nerita peloronta Linnaeus, 1758 -- valid -- bleeding tooth
  Nerita tessellata Gmelin, 1791 -- valid -- checkered nerite
  Nerita versicolor Gmelin, 1791 -- valid -- four-tooth nerite
  Neritidae Rafinesque, 1815 -- valid
  Neritina Lamarck, 1816 -- valid
  Neritina clenchi Russell, 1940 -- valid
  Neritina usnea (Roding, 1798) -- valid -- Olive Nerite
  Neritina virginea (Linnaeus, 1758) -- valid -- Virgin Nerite
  Neritopsina -- invalid
  Nesovitrea C. M. Cooke, 1921 -- valid
  Nesovitrea binneyana (E. S. Morse, 1864) -- valid -- blue glass
  Nesovitrea dalliana (Pilsbry and Simpson, 1889) -- valid -- depressed glass
  Nesovitrea electrina (Gould, 1841) -- valid -- amber glass
  Nesovitrea suzannae Pratt, 1978 -- valid -- live oak glass
  Netastoma Carpenter, 1864 -- valid
  Netastoma japonicum (Yokoyama, 1920) -- valid -- northern rostrate piddock
  Neverita duplicata (Say, 1822) -- valid -- shark eye
  Neverita nana (Møller, 1842) -- invalid -- tiny moonsnail
  Neverita politiana (Dall, 1919) -- valid -- polished moonsnail
  Neverita reclusiana (Deshayes, 1839) -- valid -- tall moonsnail
  Nipponolimopsis Habe, 1951 -- valid
  Nipponolimopsis decussata (A. Adams, 1862) -- valid -- cancellate limops
  Niso Risso, 1826 -- valid
  Niso aeglees Bush, 1885 -- valid -- brown-line niso
  Niso attilioi (C. M. Hertz and J. Hertz, 1982) -- valid
  Niso hendersoni Bartsch, 1953 -- valid
  Niso hipolitensis Bartsch, 1917 -- valid -- Hipolito niso
  Niso lomana Bartsch, 1917 -- valid
  Niso tricolor Dall, 1889 -- valid
  Nitidella Swainson, 1840 -- valid
  Nitidella nitida (Lamarck, 1822) -- valid -- glossy dovesnail
  Nitidiscala de Boury, 1909 -- valid
  Nitidiscala berryi (Dall, 1907) -- valid
  Nitidiscala caamanoi (Dall and Bartsch, 1910) -- valid -- tabulate wentletrap
  Nitidiscala californica (Dall, 1917) -- valid -- California wentletrap
  Nitidiscala hindsii (Carpenter, 1856) -- valid
  Nitidiscala indianorum (Carpenter, 1864) -- valid -- money wentletrap
  Nitidiscala sawinae (Dall, 1903) -- valid
  Nitidiscala tincta (Carpenter, 1864) -- valid -- tinted wentletrap
  Niveotectura Habe, 1944 -- valid
  Niveotectura funiculata (Carpenter, 1864) -- valid -- corded white limpet
  Niveria Jousseaume, 1884 -- valid
  Niveria antillarum (Schilder, 1922) -- valid -- Antilles trivia
  Niveria candidula (Gaskoin, 1836) -- valid -- white trivia
  Niveria leucosphaera Schilder, 1931 -- valid
  Niveria nix (Schilder, 1922) -- valid -- snowy trivia
  Niveria pediculus (Linnaeus, 1758) -- valid -- coffeebean trivia
  Niveria quadripunctata (J. E. Gray, 1827) -- valid -- fourspot trivia
  Niveria suffusa (J. E. Gray, 1827) -- valid -- pink trivia
  Nodilittorina von Martens, 1897 -- valid
  Nodilittorina angustior (Morch, 1876) -- valid -- slender periwinkle
  Nodilittorina dilatata (d'Orbigny, 1842) -- valid -- pricklywinkle
  Nodilittorina meleagris (Potiez and Michaud, 1838) -- valid -- white-spot periwinkle
  Nodilittorina mespillum (Megerle von Muhlfeld, 1824) -- valid -- brown periwinkle
  Nodilittorina riisei (Morch, 1876) -- valid
  Nodilittorina ziczac (Gmelin, 1791) -- valid -- zebra periwinkle
  Nodipecten Dall, 1898 -- valid
  Nodipecten nodosus (Linnaeus, 1758) -- valid -- lions-paw scallop
  Nodipecten subnodosus (G. B. Sowerby I, 1835) -- valid -- giant lions-paw
  Nodiscala de Boury, 1889 -- valid
  Nodiscala spongiosa (Carpenter, 1864) -- valid -- spongy wentletrap
  Noetia Gray, 1857 -- valid
  Noetia ponderosa (Say, 1822) -- valid -- ponderous ark
  Noetiidae Stewart, 1930 -- valid
  Norrisia Bayle, 1880 -- valid
  Norrisia norrisi (G. B. Sowerby II, 1838) -- valid -- norrissnail
  Notarchidae Mazzarelli, 1893 -- invalid
  Notarchus Cuvier, 1818 -- valid
  Notarchus punctatus Philippi, 1836 -- valid
  Notaspidea -- invalid
  Notobranchaea macdonaldi Pelseneer, 1886 -- valid
  Notobranchaeidae Pelseneer, 1886 -- valid
  Notodorididae Thiele, 1931 -- invalid
  Notogillia Pilsbry, 1953 -- valid
  Notogillia sathon F. G. Thompson, 1969 -- valid -- Satyr Siltsnail
  Notogillia wetherbyi (Dall, 1885) -- valid -- Alligator Siltsnail
  Nototeredo Bartsch, 1923 -- valid
  Nototeredo knoxi (Bartsch, 1917) -- valid -- knox shipworm, foliaceous shipworm
  Nototeredo norvagicus (Spengler, 1792) -- valid -- Norway shipworm
  Noumeaella Gosliner, 1991 -- valid
  Noumeaella rubrofasciata Gosliner, 1991 -- valid
  Novisuccinea Pilsbry, 1948 -- valid
  Novisuccinea chittenangoensis (Pilsbry, 1908) -- valid -- Chittenango ambersnail
  Novisuccinea ovalis (Say, 1817) -- valid -- oval ambersnail
  Noyo Roth, 1996 -- valid
  Noyo intersessa (Roth, 1987) -- valid -- Tenmile shoulderband
  Nucella Roding, 1798 -- valid
  Nucella canaliculata (Duclos, 1832) -- valid -- channeled dogwinkle
  Nucella emarginata (Deshayes, 1839) -- valid -- emarginate dogwinkle
  Nucella lamellosa (Gmelin, 1791) -- valid -- frilled dogwinkle
  Nucella lapillus (Linnaeus, 1758) -- valid -- Atlantic dogwinkle
  Nucella lima (Gmelin, 1791) -- valid -- file dogwinkle
  Nucula Lamarck, 1799 -- valid
  Nucula aegeensis Jeffreys, 1879 -- valid -- Aegean nutclam
  Nucula calcicola Moore, 1977 -- valid -- reef nutclam
  Nucula carlottensis Dall, 1897 -- valid -- Charlotte nutclam
  Nucula crenulata A. Adams, 1856 -- valid -- crenulate nutclam
  Nucula delphinodonta Mighels and C. B. Adams, 1842 -- valid -- dolphintooth nutclam
  Nucula exigua G. B. Sowerby I, 1833 -- valid -- short nutclam, iridescent nutclam
  Nucula groenlandica Posselt, 1898 -- valid -- Greenland nutclam
  Nucula proxima Say, 1822 -- valid -- Atlantic nutclam
  Nuculana Link, 1807 -- valid
  Nuculana acuta (Conrad, 1832) -- valid -- pointed nutclam
  Nuculana buccata (Møller, 1842) -- invalid -- stout nutclam
  Nuculana carpenteri (Dall, 1881) -- valid -- carpenter nutclam, smooth nutclam
  Nuculana caudata (Donovan, 1801) -- valid -- tailed nutclam
  Nuculana cellulita (Dall, 1896) -- valid -- fine-lined nutclam
  Nuculana concentrica (Say, 1824) -- valid -- concentric nutclam
  Nuculana elenensis (G. B. Sowerby I, 1833) -- valid -- Ecuador nutclam
  Nuculana fossa (Baird, 1863) -- invalid -- trenched nutclam
  Nuculana hamata (Carpenter, 1864) -- valid -- hooked nutclam
  Nuculana jamaicensis (d'Orbigny, 1842) -- valid -- Jamaica nutclam
  Nuculana minuta (Muller, 1776) -- valid -- minute nutclam
  Nuculana navisa (Dall, 1916) -- valid -- ship nutclam
  Nuculana parva (G. B. Sowerby I, 1833) -- valid -- dwarf nutclam
  Nuculana penderi (Dall and Bartsch, 1910) -- valid -- pender nutclam, sharp-point nutclam
  Nuculana pernula (Müller, 1779) -- valid -- northern nutclam
  Nuculana subaequilatera (Jeffreys, 1879) -- valid -- unequal nutclam
  Nuculana taphria (Dall, 1896) -- valid -- furrowed nutclam
  Nuculana tenuisulcata (Couthouy, 1838) -- valid -- thin nutclam
  Nuculana verrilliana (Dall, 1886) -- valid -- verrill nutclam, barbed nutclam
  Nuculanidae H. and A. Adams, 1858 -- valid
  Nuculidae Gray, 1824 -- valid
  Nuculoida -- invalid
  Nudibranchia Cuvier in Blainville, 1814 -- valid -- nudibranchs, nudibranches
  Nutricola Bernard, 1982 -- valid
  Nutricola confusa (S. Gray, 1982) -- valid -- confusing dwarf-venus
  Nutricola cymata (Dall, 1913) -- valid -- wavy dwarf-venus
  Nutricola lordi (Baird, 1863) -- valid -- Lord dwarf-venus
  Nutricola ovalis (Dall, 1902) -- valid -- oval dwarf-venus
  Nutricola tantilla (Gould, 1853) -- valid -- purple dwarf-venus
  Nuttallia Dall, 1900 -- valid
  Nuttallia nuttallii (Conrad, 1837) -- valid -- mahogany clam, California mahogany-clam
  Nuttallia obscurata (Reeve, 1857) -- valid -- purple mahogany-clam
  Nuttallina Dall, 1871 -- valid
  Nuttallina californica (Reeve, 1847) -- valid
  Nuttallina thomasi Pilsbry, 1898 -- invalid
  Obesotoma Bartsch, 1941 -- valid
  Obesotoma miona (Dall, 1919) -- valid
  Obesotoma robusta (Packard, 1867) -- valid
  Obesotoma schantarica (Middendorff, 1849) -- valid
  Obesotoma simplex (Middendorff, 1849) -- valid
  Obesotoma tenuilirata (Dall, 1871) -- valid
  Obesotoma woodiana (Moller, 1842) -- valid
  Obliquaria Rafinesque, 1820 -- valid
  Obliquaria reflexa Rafinesque, 1820 -- valid -- three-horn wartyback, threehorn wartyback
  Obovaria Rafinesque, 1819 -- valid
  Obovaria jacksoniana (Frierson, 1912) -- invalid -- southern hickorynut
  Obovaria olivaria (Rafinesque, 1820) -- valid -- hickorynut
  Obovaria retusa (Lamarck, 1819) -- valid -- golf stick pearly mussel, ring pink, ring pink mussel
  Obovaria rotulata (B. H. Wright, 1899) -- invalid -- round ebonyshell
  Obovaria subrotunda (Rafinesque, 1820) -- valid -- round hickorynut
  Obovaria unicolor (Lea, 1845) -- valid -- Alabama hickorynut
  Obtortionidae Thiele, 1925 -- invalid
  Oceanida de Folin, 1870 -- valid
  Oceanida graduata de Folin, 1870 -- valid -- shouldered eulima
  Oceanida inglei Lyons, 1978 -- valid
  Ocenotrophon McLean, 1995 -- valid
  Ocenotrophon painei (Dall, 1903) -- valid -- ribbed rocksnail
  Ocinebrina Jousseaume, 1880 -- valid
  Ocinebrina atropurpurea (Carpenter, 1865) -- valid -- purple rocksnail
  Ocinebrina barbarensis (Gabb, 1865) -- valid -- Santa Barbara rocksnail
  Ocinebrina beta (Dall, 1919) -- valid -- beta rocksnail
  Ocinebrina circumtexta (Stearns, 1871) -- valid -- circled rocksnail
  Ocinebrina foveolata (Hinds, 1844) -- valid -- dim rocksnail
  Ocinebrina gracillima (Stearns, 1871) -- valid -- graceful rocksnail
  Ocinebrina grippi (Dall, 1911) -- valid
  Ocinebrina inornata (Recluz, 1851) -- valid -- Japanese rocksnail
  Ocinebrina interfossa (Carpenter, 1864) -- valid
  Ocinebrina lurida (Middendorff, 1848) -- valid -- lurid rocksnail
  Ocinebrina minor (Dall, 1919) -- valid -- minor rocksnail
  Ocinebrina sclera (Dall, 1919) -- valid
  Ocinebrina squamulifera (Carpenter, 1869) -- valid -- scaly rocksnail
  Ocinebrina tracheia (Dall, 1919) -- valid
  Octopus bimaculoides Pickford and McConnaughey, 1949 -- valid -- California two-spot octopus
  Octopus briareus Robson, 1929 -- valid -- Caribbean reef octopus
  Octopus burryi Voss, 1950 -- valid -- brownstripe octopus, Caribbean armstripe octopus
  Octopus californicus (Berry, 1911) -- valid -- orange bigeye octopus, North Pacific bigeye octopus
  Octopus defilippi Verany, 1851 -- valid -- longarm octopus, Atlantic longarm octopus
  Octopus dofleini (Wülker, 1910) -- invalid -- North Pacific giant octopus
  Octopus joubini Robson, 1929 -- valid -- Atlantic pygmy octopus
  Octopus macropus Risso, 1826 -- valid -- Atlantic white-spotted octopus
  Octopus rubescens Berry, 1953 -- valid -- East Pacific red octopus
  Odontogena borealis (I. M. Cowan, 1964) -- invalid -- boreal kellyclam
  Odostomella Bucquoy, Dautzenberg and Dollfus, 1883 -- valid
  Odostomella doliolum (Philippi, 1844) -- valid
  Odostomia Fleming, 1813 -- valid
  Odostomia acutidens Dall, 1884 -- valid
  Odostomia aepynota Dall and Bartsch, 1909 -- valid
  Odostomia aequisculpta Carpenter, 1864 -- valid
  Odostomia aleutica Dall and Bartsch, 1909 -- valid
  Odostomia altina Dall and Bartsch, 1909 -- valid
  Odostomia americana Dall and Bartsch, 1904 -- valid
  Odostomia amiantus Dall and Bartsch, 1907 -- valid
  Odostomia amilda Dall and Bartsch, 1909 -- valid
  Odostomia angularis Dall and Bartsch, 1907 -- valid
  Odostomia arctica Dall and Bartsch, 1909 -- valid
  Odostomia astricta Dall and Bartsch, 1907 -- valid
  Odostomia atossa Dall, 1908 -- valid
  Odostomia avellana Carpenter, 1864 -- valid
  Odostomia babylonia (C. B. Adams, 1845) -- valid
  Odostomia bachia Bartsch, 1927 -- valid
  Odostomia baldridgeae Bartsch, 1912 -- valid
  Odostomia barkleyensis Dall and Bartsch, 1910 -- valid
  Odostomia beringi Dall, 1871 -- valid
  Odostomia calcarella Bartsch, 1912 -- valid
  Odostomia callimene Bartsch, 1912 -- valid
  Odostomia callimorpha Dall and Bartsch, 1909 -- valid
  Odostomia calliope Bartsch, 1912 -- valid
  Odostomia canfieldi Dall, 1908 -- valid
  Odostomia capitana Dall and Bartsch, 1909 -- valid
  Odostomia cassandra Bartsch, 1912 -- valid
  Odostomia catalinensis Bartsch, 1927 -- valid
  Odostomia chinooki Bartsch, 1927 -- valid
  Odostomia churchi A. G. Smith and M. Gordon, 1948 -- valid
  Odostomia clementensis Bartsch, 1927 -- valid
  Odostomia clementina Dall and Bartsch, 1909 -- valid
  Odostomia clessini Dall and Bartsch, 1909 -- valid
  Odostomia columbiana Dall and Bartsch, 1907 -- valid
  Odostomia cookeana Bartsch, 1910 -- valid
  Odostomia cumshewaensis Bartsch, 1921 -- valid
  Odostomia cypria Dall and Bartsch, 1912 -- valid
  Odostomia deliciosa Dall and Bartsch, 1907 -- valid
  Odostomia dicella Bartsch, 1912 -- valid
  Odostomia didyma (A. E. Verrill and Bush, 1900) -- valid
  Odostomia dinella Dall and Bartsch, 1909 -- valid
  Odostomia edmondi Jordan, 1920 -- valid
  Odostomia eldorana Bartsch, 1912 -- valid
  Odostomia elsa Dall and Bartsch, 1909 -- valid
  Odostomia engbergi Bartsch, 1920 -- valid
  Odostomia enora Dall and Bartsch, 1909 -- valid
  Odostomia esilda Dall and Bartsch, 1909 -- valid
  Odostomia eucosmia Dall and Bartsch, 1909 -- valid
  Odostomia eugena Dall and Bartsch, 1909 -- valid
  Odostomia euglypta Jordan, 1920 -- valid
  Odostomia exara Dall and Bartsch, 1907 -- valid
  Odostomia excisa Bartsch, 1912 -- valid
  Odostomia eyerdami Bartsch, 1927 -- valid
  Odostomia farallonensis Dall and Bartsch, 1909 -- valid
  Odostomia farma Dall and Bartsch, 1909 -- valid
  Odostomia fetella Dall and Bartsch, 1909 -- valid
  Odostomia franciscana Bartsch, 1917 -- valid
  Odostomia gloriosa Bartsch, 1912 -- valid
  Odostomia gouldii Carpenter, 1864 -- valid
  Odostomia gracilientis (Keep, 1887) -- valid
  Odostomia gravida Gould, 1853 -- valid
  Odostomia grippiana Bartsch, 1912 -- valid
  Odostomia hagemeisteri Dall and Bartsch, 1909 -- valid
  Odostomia harfordensis Dall and Bartsch, 1907 -- valid
  Odostomia heathi A. G. Smith and M. Gordon, 1948 -- valid
  Odostomia helena Bartsch, 1912 -- valid
  Odostomia helga Dall and Bartsch, 1909 -- valid
  Odostomia hemphilli Dall and Bartsch, 1909 -- valid
  Odostomia hendersoni Bartsch, 1909 -- valid
  Odostomia herilda Dall and Bartsch, 1909 -- valid
  Odostomia heterocincta Bartsch, 1912 -- valid
  Odostomia hypatia Dall and Bartsch, 1912 -- valid
  Odostomia hypocurta Dall and Bartsch, 1909 -- valid
  Odostomia iliuliukensis Dall and Bartsch, 1909 -- valid
  Odostomia inflata Carpenter, 1864 -- valid
  Odostomia kadiakensis Dall and Bartsch, 1909 -- valid
  Odostomia kelseyi Bartsch, 1912 -- valid
  Odostomia kennerleyi Dall and Bartsch, 1907 -- valid
  Odostomia killisnooensis Dall and Bartsch, 1909 -- valid
  Odostomia krausei Clessin, 1900 -- valid
  Odostomia laevigata (d'Orbigny, 1842) -- valid
  Odostomia lastra Dall and Bartsch, 1909 -- valid
  Odostomia martensi Dall and Bartsch, 1906 -- valid
  Odostomia moratora Dall and Bartsch, 1909 -- valid
  Odostomia movilla Dall and Bartsch, 1909 -- valid
  Odostomia nemo Dall and Bartsch, 1909 -- valid
  Odostomia nota Dall and Bartsch, 1909 -- valid
  Odostomia nuciformis Carpenter, 1864 -- valid
  Odostomia nunivakensis Dall and Bartsch, 1909 -- valid
  Odostomia oregonensis Dall and Bartsch, 1907 -- valid
  Odostomia ornatissima (Haas, 1943) -- valid
  Odostomia pesa Dall and Bartsch, 1909 -- valid
  Odostomia phanella Dall and Bartsch, 1909 -- valid
  Odostomia pharcida Dall and Bartsch, 1907 -- valid
  Odostomia pocahontasae J. B. Henderson and Bartsch, 1914 -- valid
  Odostomia pratoma Dall and Bartsch, 1909 -- valid
  Odostomia producta (C. B. Adams, 1840) -- valid
  Odostomia profundicola Dall and Bartsch, 1909 -- valid
  Odostomia quadrae Dall and Bartsch, 1910 -- valid
  Odostomia resina Dall and Bartsch, 1909 -- valid
  Odostomia richi Dall and Bartsch, 1909 -- valid
  Odostomia ritteri Dall and Bartsch, 1909 -- valid
  Odostomia sanjuanensis Bartsch, 1920 -- valid
  Odostomia satura Carpenter, 1864 -- valid
  Odostomia septentrionalis Dall and Bartsch, 1909 -- valid
  Odostomia sillana Dall and Bartsch, 1909 -- valid
  Odostomia sitkaensis Clessin, 1900 -- valid
  Odostomia skidegatensis Bartsch, 1912 -- valid
  Odostomia somersi A. E. Verrill and Bush, 1900 -- valid
  Odostomia spreadboroughi Dall and Bartsch, 1910 -- valid
  Odostomia stephensae Dall and Bartsch, 1909 -- valid
  Odostomia striata (A. E. Verrill, 1880) -- valid -- striate aclis
  Odostomia strongi Bartsch, 1927 -- valid
  Odostomia subglobosa Bartsch, 1912 -- valid
  Odostomia subturrita Dall and Bartsch, 1909 -- valid
  Odostomia sulcosa (Mighels, 1843) -- valid
  Odostomia tacomaensis Dall and Bartsch, 1907 -- valid
  Odostomia talpa Dall and Bartsch, 1909 -- valid
  Odostomia tenuisculpta Carpenter, 1864 -- valid
  Odostomia thalia Bartsch, 1912 -- valid
  Odostomia thea Bartsch, 1912 -- valid
  Odostomia tornata A. E. Verrill, 1884 -- valid
  Odostomia trachis Dall and Bartsch, 1909 -- valid
  Odostomia tremperi Bartsch, 1927 -- valid
  Odostomia turricula Dall and Bartsch, 1903 -- valid
  Odostomia unalaskensis Dall and Bartsch, 1909 -- valid
  Odostomia unidentata (Montagu, 1803) -- valid
  Odostomia valdezi Dall and Bartsch, 1907 -- valid
  Odostomia vancouverensis Dall and Bartsch, 1910 -- valid
  Odostomia virginica J. B. Henderson and Bartsch, 1914 -- valid
  Odostomia washingtonia Bartsch, 1920 -- valid
  Odostomia whitei Bartsch, 1927 -- valid
  Odostomia willetti Bartsch, 1917 -- valid
  Odostomia winkleyi Bartsch, 1909 -- valid
  Odostomia youngi Dall and Bartsch, 1910 -- valid
  Oenopota Morch, 1852 -- valid
  Oenopota alaskensis (Dall, 1871) -- valid
  Oenopota aleutica (Dall, 1871) -- valid
  Oenopota althorpensis (Dall, 1919) -- valid
  Oenopota althorpi (Dall, 1919) -- valid
  Oenopota blaneyi (Bush, 1909) -- valid
  Oenopota cancellata (Mighels and C. B. Adams, 1842) -- valid
  Oenopota chiachiana (Dall, 1919) -- valid
  Oenopota cinerea (Moller, 1842) -- valid
  Oenopota crebricostata (Carpenter, 1864) -- valid
  Oenopota elegans (Moller, 1842) -- valid
  Oenopota excurvata (Carpenter, 1864) -- valid
  Oenopota exquisita (Bartsch, 1941) -- valid
  Oenopota granitica (Dall, 1919) -- valid
  Oenopota harpa (Dall, 1885) -- valid
  Oenopota healyi (Dall, 1919) -- valid
  Oenopota impressa (Morch, 1869) -- valid
  Oenopota inequita (Dall, 1919) -- valid
  Oenopota inflata (Posselt and A. S. Jensen, 1898) -- valid
  Oenopota kyskana (Dall, 1919) -- valid
  Oenopota levidensis (Carpenter, 1864) -- valid
  Oenopota lotta (Dall, 1919) -- valid
  Oenopota luetkeni (Dall, 1919) -- valid
  Oenopota lutkeana (Krause, 1885) -- valid
  Oenopota maurellei (Dall and Bartsch, 1910) -- valid
  Oenopota mitrata (Dall, 1919) -- valid
  Oenopota murdochiana (Dall, 1885) -- valid
  Oenopota nunivakensis (Dall, 1919) -- valid
  Oenopota obliqua (G. O. Sars, 1878) -- valid
  Oenopota pavlova (Dall, 1919) -- valid
  Oenopota pingelii (Moller, 1842) -- valid
  Oenopota pribilova (Dall, 1919) -- valid
  Oenopota pusilla (A. E. Verrill, 1882) -- valid
  Oenopota pyramidalis (Strom, 1788) -- valid
  Oenopota regulus (Dall, 1919) -- valid
  Oenopota sculpturata (Dall, 1887) -- valid
  Oenopota solida (Dall, 1887) -- valid
  Oenopota subvitrea (A. E. Verrill, 1884) -- valid
  Oenopota tabulata (Carpenter, 1864) -- valid
  Oenopota tenuissima (Dall, 1919) -- valid
  Ogaridiscus Chamberlin and Jonas, 1929 -- valid
  Ogaridiscus subrupicola (Dall, 1877) -- valid -- southern tightcoil
  Okenia Leuckart and Bronn in Menke, 1830 -- valid
  Okenia angelensis Lance, 1966 -- valid -- Angeles okenia
  Okenia cupella (Vogel and Schultz, 1970) -- valid
  Okenia impexa Er. Marcus, 1957 -- valid
  Okenia plana Baba, 1960 -- valid -- flat okenia
  Okenia quadricornis (Montagu, 1815) -- valid -- seasquirt okenia
  Okenia sapelona Ev. Marcus and Er. Marcus, 1967 -- valid -- Sapelo okenia
  Okenia vancouverensis (O'Donoghue, 1921) -- valid -- Vancouver okenia
  Okenia zoobotryon (Smallwood, 1910) -- valid
  Oldroydia Dall, 1894 -- valid
  Oldroydia percrassa (Dall, 1894) -- valid
  Olea Agersborg, 1923 -- valid
  Olea hansineensis Agersborg, 1923 -- valid -- Hansine seaslug
  Oleacinidae H. Adams and A. Adams, 1855 -- valid
  Oligyra Say, 1818 -- valid
  Oligyra orbiculata (Say, 1818) -- valid -- globular drop
  Oliva Bruguiere, 1789 -- valid
  Oliva bifasciata Kuster, 1878 -- valid
  Oliva bifasciata sunderlandi Petuch, 1987 -- valid
  Oliva bollingi Clench, 1937 -- valid
  Oliva sayana Ravenel, 1834 -- valid -- lettered olive
  Olivella Swainson, 1831 -- valid
  Olivella adelae Olsson, 1956 -- invalid
  Olivella alectona (Duclos, 1835) -- valid -- San Pedro dwarf olive
  Olivella baetica Carpenter, 1864 -- valid -- beatic dwarf olive
  Olivella biplicata (G. B. Sowerby I, 1825) -- valid -- purple dwarf olive
  Olivella bullula (Reeve, 1850) -- valid -- bubble dwarf olive
  Olivella dealbata (Reeve, 1850) -- valid -- whitened dwarf olive
  Olivella floralia (Duclos, 1853) -- valid -- rice olive
  Olivella fuscocincta Dall, 1889 -- valid
  Olivella inusta G. B. Sowerby III, 1915 -- valid
  Olivella lactea (Marrat, 1871) -- valid
  Olivella macgintyi Olsson, 1956 -- valid
  Olivella minuta (Link, 1807) -- valid -- minute dwarf olive
  Olivella mutica (Say, 1822) -- valid -- variable dwarf olive
  Olivella nivea (Gmelin, 1791) -- valid -- snowy dwarf olive
  Olivella parva T. S. Oldroyd, 1921 -- valid
  Olivella pedroana (Conrad, 1856) -- invalid -- San Pedro dwarf olive
  Olivella perplexa Olsson, 1956 -- valid
  Olivella pusilla (Marrat, 1871) -- valid -- tiny dwarf olive
  Olivella rotunda Dall, 1889 -- valid
  Olivella stegeri Olsson, 1956 -- valid
  Olivella strigata (Reeve, 1850) -- valid
  Olivella thompsoni Olsson, 1956 -- valid
  Olivella watermani McGinty, 1940 -- valid
  Olividae Latreille, 1825 -- valid
  Olssonella Petit, 1970 -- invalid
  Olssonella smithi (Dall, 1880) -- invalid
  Omalogyra Jeffreys, 1859 -- valid
  Omalogyra atomus (Philippi, 1841) -- valid -- atom snail
  Omalogyridae P. Fischer, 1885 -- invalid
  Ommastrephes bartramii (Lesueur, 1821) -- valid -- red flying squid
  Onchidella Gray, 1850 -- valid
  Onchidella borealis Dall, 1871 -- valid -- northwest onchidella
  Onchidella brattstroemi Ev. Marcus, 1978 -- valid
  Onchidella carpenteri (W. G. Binney, 1860) -- valid
  Onchidella floridana (Dall, 1885) -- valid -- Florida onchidella
  Onchidella wah Ev. Marcus, 1978 -- valid
  Onchidiidae Gray, 1824 -- invalid
  Onchidiopsis Bergh, 1853 -- valid
  Onchidiopsis corys Balch, 1910 -- valid
  Onchidiopsis glacialis (M. Sars, 1851) -- valid -- icy lamellaria
  Onchidiopsis hannai Dall, 1916 -- valid
  Onchidiopsis kingmaruensis Russell, 1942 -- valid -- Baffin lamellaria
  Onchidorididae Gray, 1827 -- valid
  Onchidoris de Blainville, 1816 -- valid
  Onchidoris bilamellata (Linnaeus, 1767) -- valid -- barnacle-eating onchidoris
  Onchidoris diademata (Gould, 1870) -- valid
  Onchidoris grisea (Gould, 1870) -- valid
  Onchidoris muricata (Muller, 1776) -- valid -- fuzzy onchidoris
  Onchidoris tenella (Gould, 1870) -- valid
  Onoba H. Adams and A. Adams, 1852 -- valid
  Onoba aculeus (Gould, 1841) -- valid -- pointed cingula
  Onoba aurivillii (Dall, 1887) -- valid
  Onoba bakeri (Bartsch, 1910) -- valid
  Onoba carpenteri (Weinkauff, 1885) -- valid
  Onoba castanella (Dall, 1886) -- valid
  Onoba cerinella Dall, 1887 -- valid
  Onoba dalli (Bartsch, 1927) -- valid
  Onoba exarata (Stimpson, 1851) -- valid
  Onoba forresterensis (Willett, 1934) -- valid
  Onoba kyskensis (Bartsch, 1911) -- valid
  Onoba mighelsi (Stimpson, 1851) -- valid
  Onoba muriei (Bartsch and Rehder, 1939) -- valid
  Onoba palmeri (Dall, 1919) -- valid
  Onobops F. G. Thompson, 1969 -- valid
  Onobops crassus (F. G. Thompson, 1968) -- valid -- spartina hydrobe
  Onobops jacksoni (Bartsch, 1953) -- valid -- Fine-lined Hydrobe
  Oocorys P. Fischer, 1883 -- valid
  Oocorys bartschi Rehder, 1943 -- valid -- giant false tun, giant false-tun
  Oocorys sulcata P. Fischer, 1883 -- valid -- sulcate false tun, sulcate false-tun
  Oocorythinae P. Fischer, 1885 -- valid
  Opalia H. Adams and A. Adams, 1853 -- valid
  Opalia abbotti Clench and Turner, 1952 -- valid
  Opalia andrewsii (A. E. Verrill, 1882) -- valid
  Opalia aurifila (Dall, 1889) -- valid -- fine-mesh wentletrap
  Opalia borealis Keep, 1881 -- valid -- boreal wentletrap
  Opalia burryi Clench and Turner, 1950 -- valid
  Opalia crenata (Linnaeus, 1758) -- valid -- coarse wentletrap
  Opalia eolis Clench and Turner, 1950 -- valid -- cancellate wentletrap
  Opalia funiculata (Carpenter, 1857) -- valid -- scalloped wentletrap
  Opalia hotessieriana (d'Orbigny, 1842) -- valid -- pitted wentletrap
  Opalia infrequens (C. B. Adams, 1852) -- valid -- sparse wentletrap
  Opalia leeana (A. E. Verrill, 1883) -- valid
  Opalia montereyensis (Dall, 1907) -- valid -- Monterey wentletrap
  Opalia pumilio (Morch, 1874) -- valid -- dwarf wentletrap
  Opaliopsis Thiele, 1928 -- valid
  Opaliopsis atlantis (Clench and Turner, 1952) -- valid -- Atlantic wentletrap
  Opaliopsis concava (Dall, 1889) -- valid -- concave wentletrap
  Opeas Albers, 1850 -- valid
  Opeas pumilum (Pfeiffer, 1840) -- valid -- dwarf awlsnail
  Opeas pyrgula Schmacker and Boettger, 1891 -- valid -- sharp awlsnail
  Ophiodermella Bartsch, 1944 -- valid
  Ophiodermella cancellata (Carpenter, 1864) -- valid -- cancellate snakeskin-snail
  Ophiodermella fancherae (Dall, 1903) -- valid
  Ophiodermella inermis (Reeve, 1843) -- valid -- gray snakeskin-snail
  Oreohelicidae Pilsbry, 1939 -- valid
  Oreohelix Pilsbry, 1904 -- valid
  Oreohelix alpina (Elrod, 1901) -- valid -- alpine mountainsnail
  Oreohelix amariradix Pilsbry, 1934 -- valid -- Bitter Root mountainsnail
  Oreohelix anchana Gregg, 1953 -- valid -- Ancha mountainsnail
  Oreohelix barbata Pilsbry, 1905 -- valid -- bearded mountainsnail
  Oreohelix californica S. S. Berry, 1931 -- valid -- Clark mountainsnail
  Oreohelix carinifera Pilsbry, 1912 -- valid -- keeled mountainsnail
  Oreohelix concentrata (Dall, 1896) -- valid -- Huachuca mountainsnail
  Oreohelix confragosa Metcalf, 1974 -- valid -- Pinos Altos mountainsnail
  Oreohelix elrodi (Pilsbry, 1900) -- valid -- carinate mountainsnail
  Oreohelix eurekensis J. Henderson and Daniels, 1916 -- valid -- Eureka mountainsnail
  Oreohelix florida Pilsbry, 1939 -- valid -- florida mountainsnail
  Oreohelix grahamensis Gregg and W. B. Miller, 1974 -- valid -- Pinaleno mountainsnail
  Oreohelix hammeri Fairbanks, 1984 -- valid -- Seven Devils mountainsnail
  Oreohelix handi Pilsbry and Ferriss, 1918 -- valid -- Spring mountainsnail
  Oreohelix haydeni (Gabb, 1869) -- valid -- lyrate mountainsnail
  Oreohelix hemphilli (Newcomb, 1869) -- valid -- Whitepine mountainsnail
  Oreohelix hendersoni Pilsbry, 1912 -- valid -- pallid mountainsnail
  Oreohelix houghi W. B. Marshall, 1929 -- valid -- Diablo mountainsnail
  Oreohelix howardi Jones, 1944 -- valid -- Mill Creek mountainsnail
  Oreohelix idahoensis (Newcomb, 1866) -- valid -- costate mountainsnail
  Oreohelix intersum (Hemphill, 1890) -- valid -- Deep Slide mountainsnail
  Oreohelix jaegeri S. S. Berry, 1931 -- valid -- Kyle Canyon mountainsnail
  Oreohelix jugalis (Hemphill, 1890) -- valid -- Boulder Pile mountainsnail
  Oreohelix junii Pilsbry, 1934 -- valid -- Grand Coulee mountainsnail
  Oreohelix litoralis Crews and Metcalf, 1982 -- valid -- san augustin mountainsnail
  Oreohelix magdalenae Pilsbry, 1939 -- valid -- Magdalena mountainsnail
  Oreohelix metcalfei Cockerell, 1905 -- valid -- Black Range mountainsnail
  Oreohelix nevadensis S. S. Berry, 1932 -- valid -- Schell Creek mountainsnail
  Oreohelix parawanensis Gregg, 1941 -- valid -- Brian Head mountainsnail
  Oreohelix peripherica (Ancey, 1881) -- valid -- Deseret mountainsnail
  Oreohelix pilsbryi Ferriss, 1917 -- valid -- Mineral Creek mountainsnail
  Oreohelix pygmaea Pilsbry, 1913 -- valid -- pygmy mountainsnail
  Oreohelix socorroensis Pilsbry, 1905 -- valid -- Socorro mountainsnail
  Oreohelix strigosa (Gould, 1846) -- valid -- Rocky mountainsnail
  Oreohelix subrudis (Reeve, 1854) -- valid -- subalpine mountainsnail
  Oreohelix swopei Pilsbry and Ferriss, 1917 -- valid -- Morgan Creek mountainsnail
  Oreohelix tenuistriata J. Henderson and Daniels, 1916 -- valid -- thin-ribbed mountainsnail
  Oreohelix variabilis J. Henderson, 1929 -- valid
  Oreohelix vortex S. S. Berry, 1932 -- valid -- whorled mountainsnail
  Oreohelix waltoni Solem, 1975 -- valid -- lava rock mountainsnail
  Oreohelix yavapai Pilsbry, 1905 -- valid -- Yavapai mountainsnail
  Orinella Dall and Bartsch, 1904 -- valid
  Orinella vanhyningi Bartsch, 1944 -- valid
  Ornithoteuthis antillarum Adam, 1957 -- valid -- Atlantic bird squid
  Orobitella Dall, 1900 -- valid
  Orobitella californica (Dall, 1899) -- valid -- California erycina
  Orobitella floridana (Dall, 1899) -- valid -- giant montacutid
  Orobitella limpida (Dall, 1899) -- valid -- limpid montacutid
  Orthalicus Beck, 1837 -- valid
  Orthalicus floridensis Pilsbry, 1899 -- valid -- banded treesnail
  Orthalicus reses (Say, 1830) -- valid -- Stock Island treesnail
  Orthalicus reses nesodryas Pilsbry, 1946 -- valid -- Florida Keys treesnail
  Orthalicus reses reses (Say, 1830) -- valid -- Stock Island treesnail
  Ostrea Linnaeus, 1758 -- valid -- flat oysters, huîtres plates, ostras
  Ostrea conchaphila P. P. Carpenter, 1857 -- valid -- ostra Olimpia, Olympia oyster, Shell-loving oyster, huître plate Olympie
  Ostrea edulis Linnaeus, 1758 -- valid -- European flat oyster, huître plate européenne, ostra europea, edible oyster
  Ostrea equestris Say, 1834 -- valid -- crested oyster
  Ostreidae Rafinesque, 1815 -- valid -- flat oysters, cupped oysters, huîtres plates, huîtres creuses, ostras, ostiones
  Ostreoida -- invalid
  Ostreola conchaphila (P. P. Carpenter, 1857) -- invalid
  Ostreola equestris (Say, 1834) -- invalid -- crested oyster
  Otala Schumacher, 1817 -- valid
  Otala lactea (Muller, 1774) -- valid -- milk snail
  Ovulidae Fleming, 1822 -- valid
  Oxychilus Fitzinger, 1833 -- valid
  Oxychilus alliarius (J. S. Miller, 1822) -- valid -- garlic glass-snail
  Oxychilus cellarius (Muller, 1774) -- valid -- cellar glass-snail
  Oxychilus draparnaudi (Beck, 1837) -- valid -- dark-bodied glass-snail
  Oxychilus helveticus (Blum, 1881) -- valid -- Swiss glass-snail
  Oxygyrus Benson, 1835 -- valid
  Oxygyrus keraudrenii (Lesueur, 1817) -- valid
  Oxyloma Westerlund, 1885 -- valid
  Oxyloma decampi (Tryon, 1866) -- valid -- Marshall ambersnail
  Oxyloma deprimidum Franzen, 1973 -- valid
  Oxyloma effusum (Pfeiffer, 1853) -- valid -- coastal plain ambersnail, coastal-plain ambersnail
  Oxyloma groenlandicum (Moller, 1842) -- valid -- ruddy ambersnail
  Oxyloma hawkinsi (Baird, 1863) -- valid -- boundary ambersnail
  Oxyloma haydeni (W. G. Binney, 1858) -- valid -- Niobrara ambersnail
  Oxyloma kanabense Pilsbry, 1948 -- valid -- Kanab ambersnail
  Oxyloma missoula Hubricht, 1982 -- valid -- Ninepipes ambersnail
  Oxyloma nuttallianum (I. Lea, 1841) -- valid -- oblique ambersnail
  Oxyloma peoriense (Wolf, 1894) -- valid -- depressed ambersnail
  Oxyloma retusum (I. Lea, 1834) -- valid -- blunt ambersnail
  Oxyloma salleanum (Pfeiffer, 1849) -- valid -- Louisiana ambersnail
  Oxyloma sillimani (Bland, 1865) -- valid -- Humboldt ambersnail
  Oxyloma subeffusum Pilsbry, 1948 -- valid -- Chesapeake ambersnail
  Oxyloma verrilli (Bland, 1865) -- valid -- maritime ambersnail
  Oxynoe Rafinesque, 1814 -- valid
  Oxynoe antillarum Morch, 1863 -- valid -- Antilles oxynoe
  Oxynoe azuropunctata K. R. Jensen, 1980 -- valid -- blue-spot oxynoe
  Oxynoidae H. Adams and A. Adams, 1854 -- invalid
  Pachystremiscus Olsson and McGinty, 1942 -- valid
  Pachystremiscus ornatus (Olsson and McGinty, 1958) -- valid
  Pachystremiscus pulchellus (Olsson and McGinty, 1958) -- valid
  Paedoclione doliiformis Danforth, 1907 -- valid
  Palio Gray, 1857 -- valid
  Palio dubia (M. Sars, 1829) -- valid
  Palio nothus (Johnston, 1838) -- valid
  Palio pallida Bergh, 1880 -- valid
  Palio zosterae (O'Donoghue, 1924) -- valid -- eelgrass polycera
  Palisa Edmunds, 1964 -- valid
  Palisa kristenseni (Ev. Marcus and Er. Marcus, 1963) -- valid
  Pallifera E. S. Morse, 1864 -- valid
  Pallifera dorsalis (A. Binney, 1842) -- valid -- pale mantleslug
  Pallifera fosteri F. C. Baker, 1939 -- valid -- Foster mantleslug
  Pallifera hemphilli (W. G. Binney, 1885) -- valid -- black mantleslug
  Pallifera marmorea Pilsbry, 1948 -- valid -- marbled mantleslug
  Pallifera megaphallica Grimm, 1961 -- valid -- woody mantleslug
  Pallifera ohioensis (Sterki, 1908) -- valid -- redfoot mantleslug
  Pallifera pilsbryi C. D. Miles and Mead, 1960 -- valid -- Arizona mantleslug
  Pallifera secreta (Cockerell, 1900) -- valid -- severed mantleslug
  Pallifera tournescalis Branson, 1968 -- valid -- Ouachita mantleslug
  Pallifera varia Hubricht, 1953 -- valid -- variable mantleslug
  Palliolum di Monterosato, 1884 -- valid
  Palliolum striatum (Muller, 1776) -- valid -- striate scallop
  Panacca Dall, 1905 -- valid
  Panacca arata (A. E. Verrill and S. Smith, 1881) -- valid -- panacca clam
  Pandora Chemnitz, 1795 -- valid
  Pandora arenosa Conrad, 1834 -- valid -- sandy pandora
  Pandora bilirata Conrad, 1855 -- valid -- bilirate pandora
  Pandora bushiana Dall, 1886 -- valid -- bush pandora, keeled pandora
  Pandora filosa (Carpenter, 1864) -- valid -- threaded pandora
  Pandora glacialis Leach, 1819 -- valid -- glacial pandora
  Pandora gouldiana Dall, 1886 -- valid -- gould pandora, rounded pandora
  Pandora inflata Boss and Merrill, 1965 -- valid -- inflated pandora
  Pandora inornata A. E. Verrill and Bush, 1898 -- valid -- inornate pandora
  Pandora punctata Conrad, 1837 -- valid -- punctate pandora
  Pandora trilineata Say, 1822 -- valid -- three-line pandora, threeline pandora
  Pandora wardiana A. Adams, 1859 -- valid -- ward pandora, giant pandora
  Pandoridae Rafinesque, 1815 -- valid
  Panomya Gray, 1857 -- valid
  Panomya ampla Dall, 1898 -- valid -- ample roughmya
  Panomya arctica (Lamarck, 1818) -- invalid -- arctic roughmya
  Panomya norvegica (Spengler, 1793) -- valid -- Arctic roughmya
  Panomya priapus (Tilesius, 1822) -- valid -- Bering roughmya
  Panopea Menard, 1807 -- valid
  Panopea abrupta (Conrad, 1849) -- valid
  Panopea bitruncata (Conrad, 1872) -- valid -- Atlantic geoduck
  Papyridea Swainson, 1840 -- valid
  Papyridea semisulcata (J. E. Gray, 1825) -- valid -- frilled papercockle
  Papyridea soleniformis (Bruguiere, 1789) -- valid -- spiny papercockle
  Parabornia Boss, 1965 -- valid
  Parabornia squillina Boss, 1965 -- valid -- squillaclam
  Paraclione longicaudata (Souleyet, 1852) -- valid
  Parahyotissa Harry, 1985 -- valid
  Parahyotissa mcgintyi Harry, 1985 -- valid -- mcginty oyster
  Paralaoma Iredale, 1913 -- valid
  Paralaoma caputspinulae (Reeve, 1852) -- valid -- pinhead spot
  Paramya Conrad, 1860 -- valid
  Paramya subovata (Conrad, 1845) -- valid -- subovate softshell clam, subovate softshell
  Parapholas Conrad, 1848 -- valid
  Parapholas californica (Conrad, 1837) -- valid -- scaleside piddock
  Parastarte Conrad, 1862 -- valid
  Parastarte triquetra (Conrad, 1846) -- valid -- brown gemclam
  Paravitrea Pilsbry, 1898 -- valid
  Paravitrea alethia Hubricht, 1978 -- valid -- goddess supercoil
  Paravitrea amicalola Hubricht, 1976 -- valid -- tight supercoil
  Paravitrea andrewsae (W. G. Binney, 1879) -- valid -- high mountain supercoil
  Paravitrea aulacogyra (Pilsbry and Ferris, 1906) -- valid
  Paravitrea bellona Hubricht, 1978 -- valid -- club supercoil
  Paravitrea bidens Hubricht, 1963 -- valid -- gray supercoil
  Paravitrea blarina Hubricht, 1963 -- valid -- shrew supercoil
  Paravitrea calcicola H. B. Baker, 1931 -- valid -- pearl supercoil
  Paravitrea capsella (Gould, 1851) -- valid -- dimple supercoil
  Paravitrea ceres Hubricht, 1978 -- valid -- sidelong supercoil
  Paravitrea clappi (Pilsbry, 1898) -- valid -- Mirey Ridge supercoil
  Paravitrea conecuhensis (G. H. Clapp, 1917) -- valid -- triangular supercoil
  Paravitrea dentilla Hubricht, 1978 -- valid -- comb supercoil
  Paravitrea diana Hubricht, 1983 -- valid -- hunted supercoil
  Paravitrea grimmi Hubricht, 1968 -- valid -- buff supercoil
  Paravitrea hera Hubricht, 1983 -- valid -- spirit supercoil
  Paravitrea lacteodens (Pilsbry, 1903) -- valid -- Ramp Cove supercoil
  Paravitrea lamellidens (Pilsbry, 1898) -- valid -- lamellate supercoil
  Paravitrea lapilla Hubricht, 1965 -- valid -- gem supercoil
  Paravitrea metallacta Hubricht, 1963 -- valid -- Caneyfork supercoil
  Paravitrea mira Hubricht, 1975 -- valid -- funnel supercoil
  Paravitrea multidentata (A. Binney, 1840) -- valid -- dentate supercoil
  Paravitrea petrophila (Bland, 1883) -- valid -- Cherokee supercoil
  Paravitrea pilsbryana (G. H. Clapp, 1919) -- valid -- translucent supercoil
  Paravitrea placentula (Shuttleworth, 1852) -- valid -- glossy supercoil
  Paravitrea pontis H. B. Baker, 1931 -- valid -- Natural Bridge supercoil
  Paravitrea reesei Morrison, 1937 -- valid -- round supercoil
  Paravitrea septadens Hubricht, 1978 -- valid -- brown supercoil
  Paravitrea seradens Hubricht, 1972 -- valid -- barred supercoil
  Paravitrea significans (Bland, 1866) -- valid -- domed supercoil
  Paravitrea simpsoni (Pilsbry, 1889) -- valid -- amber supercoil
  Paravitrea smithi (Walker, 1928) -- valid -- Sand Mountain supercoil
  Paravitrea subtilis Hubricht, 1978 -- valid -- slender supercoil
  Paravitrea tantilla Hubricht, 1963 -- valid -- teasing supercoil
  Paravitrea ternaria Hubricht, 1978 -- valid -- sculpted supercoil
  Paravitrea tiara Hubricht, 1978 -- valid -- crowned supercoil
  Paravitrea toma Hubricht, 1975 -- valid -- sharp supercoil
  Paravitrea tridens Pilsbry, 1946 -- valid -- white-footed supercoil, white foot supercoil
  Paravitrea umbilicaris (Ancey, 1887) -- valid -- open supercoil
  Paravitrea variabilis H. B. Baker, 1929 -- valid -- variable supercoil
  Paravitrea varidens Hubricht, 1978 -- valid -- roan supercoil
  Parvamussium Sacco, 1897 -- valid
  Parvamussium alaskense (Dall, 1871) -- valid -- Alaska glass-scallop
  Parvanachis Radwin, 1968 -- valid
  Parvanachis obesa (C. B. Adams, 1845) -- valid -- fat dovesnail
  Parvanachis ostreicola (G. B. Sowerby III, 1882) -- valid -- oyster dovesnail
  Parvilucina Dall, 1901 -- valid
  Parvilucina approximata (Dall, 1901) -- valid -- approximate lucine, beaked lucine
  Parvilucina costata (d'Orbigny, 1842) -- valid -- costate lucine
  Parvilucina multilineata (Tuomey and Holmes, 1857) -- valid -- many-lined lucine, many-line lucine
  Parvilucina tenuisculpta (Carpenter, 1864) -- valid -- fine-lined lucine, fine-line lucine
  Parviphos Sarasua, 1984 -- valid
  Parviphos adelus (Schwengel, 1942) -- valid
  Parviturbo Pilsbry and McGinty, 1945 -- valid
  Parviturbo acuticostatus (Carpenter, 1864) -- valid -- sharp-rib cyclostreme
  Parviturbo calidimaris Pilsbry and McGinty, 1945 -- valid -- tropical cyclostreme
  Parviturbo francesae Pilsbry and McGinty, 1945 -- valid
  Parviturbo rehderi Pilsbry and McGinty, 1945 -- valid
  Parviturbo turbinus (Dall, 1889) -- valid
  Parviturbo weberi Pilsbry and McGinty, 1945 -- valid
  Parviturboides Pilsbry and McGinty, 1950 -- valid
  Parviturboides interruptus (C. B. Adams, 1850) -- valid -- interrupted vitrinella
  Patellogastropoda -- invalid
  Patelloida Quoy and Gaimard, 1834 -- valid
  Patelloida pustulata (Helbling, 1779) -- valid -- spotted limpet
  Patera Albers, 1850 -- valid
  Patera appressa (Say, 1821) -- valid -- flat bladetooth
  Patera binneyana (Pilsbry, 1899) -- valid -- half-lidded oval
  Patera clarki (I. Lea, 1858) -- valid -- dwarf proud globe
  Patera clarki clarki (I. Lea, 1858) -- valid -- dwarf proud globe
  Patera clarki nantahala Clench, 1933 -- valid -- noonday globe
  Patera clenchi (Rehder, 1932) -- valid -- Calico Rock oval
  Patera indianorum (Pilsbry, 1899) -- valid -- lidded oval
  Patera kiowaensis (Simpson, 1888) -- valid -- drywoods oval
  Patera laevior (Pilsbry, 1940) -- valid -- smooth bladetooth
  Patera leatherwoodi (Pratt, 1971) -- valid -- Pedernales oval
  Patera panselenus (Hubricht, 1976) -- valid -- Virginia bladetooth
  Patera pennsylvanica (Green, 1827) -- valid -- proud globelet
  Patera perigrapta (Pilsbry, 1894) -- valid -- engraved bladetooth
  Patera roemeri (Pfeiffer, 1848) -- valid -- Texas oval
  Patera sargentiana (C. W. Johnson and Pilsbry, 1892) -- valid -- grand bladetooth
  Patinopecten caurinus (Gould, 1850) -- valid -- weathervane scallop
  Pecosorbis Taylor, 1985 -- valid
  Pecosorbis kansasensis (S. S. Berry, 1966) -- valid -- New Mexico Ramshorn
  Pecten Muller, 1776 -- valid
  Pecten chazaliei Dautzenberg, 1900 -- valid -- tereinus scallop, dwarf zigzag scallop
  Pecten diegensis Dall, 1898 -- invalid -- San Diego scallop
  Pecten raveneli Dall, 1898 -- invalid -- Ravenel scallop
  Pecten ziczac (Linnaeus, 1758) -- invalid -- zigzag scallop
  Pectinella A. E. Verrill, 1897 -- valid
  Pectinella sigsbeei (Dall, 1886) -- valid -- sigsbee scallop, glass scallop
  Pectinidae Rafinesque, 1815 -- valid
  Pedicularia Swainson, 1840 -- valid
  Pedicularia californica Newcomb, 1864 -- valid -- California pedicularia
  Pedicularia decussata Gould, 1855 -- valid -- hatched pedicularia
  Pedipes Ferussac, 1821 -- valid
  Pedipes angulatus C. B. Adams, 1852 -- valid -- angular pedipes
  Pedipes mirabilis (Megerle von Muhlfeld, 1816) -- valid -- miraculous pedipes
  Pedipes ovalis (C. B. Adams, 1849) -- valid
  Pedipes unisulcatus J. G. Cooper, 1867 -- valid -- one-groove pedipes
  Pegias Simpson, 1900 -- valid
  Pegias fabula (Lea, 1838) -- valid -- littlewing pearlymussel, little-wing pearly mussel
  Pelseneeria Koehler and Vaney, 1908 -- valid
  Pelseneeria stimpsonii (A. E. Verrill, 1872) -- valid
  Peltodoris Bergh, 1880 -- valid
  Peltodoris greeleyi MacFarland, 1909 -- valid
  Pelycidiidae Ponder and Hall, 1983 -- valid
  Pelycidion Fischer, 1873 -- valid
  Pelycidion kelseyi (Bartsch, 1911) -- valid
  Penitella Valenciennes, 1846 -- valid
  Penitella conradi Valenciennes, 1846 -- valid -- abalone piddock
  Penitella fitchi Turner, 1955 -- valid -- Fitch piddock
  Penitella hopkinsi Kennedy and Armentrout, 1989 -- valid -- chimney piddock
  Penitella penita (Conrad, 1837) -- valid -- flap-tip piddock
  Penitella richardsoni Kennedy, 1989 -- valid -- Monterey piddock
  Penitella turnerae Evans and Fisher, 1966 -- valid -- Turner piddock
  Peracle Forbes, 1844 -- valid
  Peracle bispinosa Pelseneer, 1888 -- valid -- two-spine pteropod
  Peracle diversa di Monterosato, 1875 -- valid
  Peracle reticulata (d'Orbigny, 1836) -- valid -- reticulate pteropod
  Peracle triacantha P. Fischer, 1882 -- valid
  Peraclididae C. W. Johnson, 1915 -- invalid
  Periglypta Jukes-Browne, 1914 -- valid
  Periglypta listeri (J. E. Gray, 1838) -- valid -- princess venus
  Periploma Schumacher, 1817 -- valid
  Periploma affine A. E. Verrill and Bush, 1898 -- valid -- arelated spoonclam, related spoonclam
  Periploma aleuticum (Krause, 1885) -- valid -- Aleutian spoonclam
  Periploma anguliferum (Philippi, 1847) -- valid -- angled spoonclam
  Periploma discus Stearns, 1890 -- valid -- round spoonclam
  Periploma fragile (Totten, 1835) -- valid -- fragile spoonclam
  Periploma leanum (Conrad, 1831) -- valid -- lea spoonclam, oval spoonclam
  Periploma margaritaceum (Lamarck, 1801) -- valid -- unequal spoonclam
  Periploma papyratium (Say, 1822) -- valid -- paper spoonclam
  Periploma planiusculum G. B. Sowerby I, 1834 -- valid -- flat spoonclam
  Periploma tenerum P. Fischer, 1882 -- valid -- delicate spoonclam
  Periplomatidae Dall, 1895 -- valid
  Peristichia Dall, 1889 -- valid
  Peristichia agria Dall, 1889 -- valid
  Peristichia pedroana (Dall and Bartsch, 1909) -- valid
  Peristichia toreta Dall, 1889 -- valid
  Perna Philipsson, 1788 -- valid
  Perna perna (Linnaeus, 1758) -- valid -- Mexilhao mussel
  Perotrochus P. Fischer, 1885 -- valid
  Perotrochus amabilis (Bayer, 1963) -- valid -- lovely slitsnail
  Perotrochus maureri Harasewych and Askew, 1993 -- valid
  Perotrochus quoyanus (P. Fischer and Bernardi, 1856) -- valid
  Persicula Schumacher, 1817 -- valid
  Persicula catenata (Montagu, 1803) -- valid -- princess marginella
  Persicula pulcherrima (Gaskoin, 1849) -- valid -- decorated marginella
  Personidae Gray, 1854 -- valid
  Petalifera Gray, 1847 -- valid
  Petalifera ramosa Baba, 1959 -- valid
  Petaloconchus I. Lea, 1843 -- valid
  Petaloconchus compactus (Carpenter, 1864) -- valid -- compact wormsnail
  Petaloconchus erectus (Dall, 1888) -- valid -- erect wormsnail
  Petaloconchus montereyensis Dall, 1919 -- valid -- Monterey wormsnail
  Petaloconchus varians (d'Orbigny, 1841) -- valid -- variable wormsnail
  Petitilla Wise, 1996 -- valid
  Petitilla crosseana (Dall, 1885) -- valid
  Petricola californiensis Pilsbry and Lowe, 1932 -- valid -- California petricola, California petricolid
  Petricola carditoides (Conrad, 1837) -- valid -- hearty petricolid, hearty petricola
  Petricola hertzana Coan, 1997 -- valid -- kelp petricolid
  Petricola lapicida (Gmelin, 1791) -- valid -- boring petricola
  Petricola pholadiformis Lamarck, 1818 -- invalid -- false angelwing
  Petricolaria pholadiformis (Lamarck, 1818) -- valid -- false angelwing
  Petricolidae Deshayes, 1831 -- valid
  Phalium Link, 1807 -- valid
  Phalium coronadoi (Crosse, 1867) -- valid -- Coronado bonnet
  Phalium granulatum (Born, 1778) -- valid -- Scotch bonnet
  Pharidae H. and A. Adams, 1856 -- valid
  Phenacolepadidae Pilsbry, 1895 -- valid
  Phenacolepas Pilsbry, 1891 -- invalid
  Phenacolepas hamillei (P. Fischer, 1857) -- invalid
  Phenacovolva Iredale, 1930 -- valid
  Phenacovolva piragua (Dall, 1889) -- valid -- slender simnia
  Phidiana Gray, 1850 -- valid
  Phidiana hiltoni (O'Donoghue, 1927) -- valid -- pugnaceous aeolis
  Phidiana lynceus Bergh, 1867 -- valid
  Philine Ascanius, 1772 -- valid
  Philine alba Mattox, 1958 -- valid -- white paper-bubble, white paperbubble
  Philine angulata Jeffreys, 1867 -- valid -- angled paper-bubble, angled paperbubble
  Philine auriformis Suter, 1909 -- valid
  Philine bakeri Dall, 1919 -- valid
  Philine californica Willett, 1944 -- valid -- california paper-bubble, California paperbubble
  Philine cingulata G. O. Sars, 1878 -- valid -- girdled paper-bubble, girdled paperbubble
  Philine fragilis G. O. Sars, 1878 -- valid -- fragile paper-bubble, fragile paperbubble
  Philine lima (T. Brown, 1825) -- valid -- file paper-bubble, file paperbubble
  Philine polaris Aurivillius, 1885 -- valid -- axial paper-bubble, axial paperbubble
  Philine polystrigma (Dall, 1908) -- valid
  Philine quadrata (S. V. Wood, 1839) -- valid -- quadrate paper-bubble, quadrate paperbubble
  Philine sagra (d'Orbigny, 1841) -- valid -- crenulate paper-bubble, crenulate paperbubble
  Philine sinuata Stimpson, 1851 -- valid -- sinuate paper-bubble, sinuate paperbubble
  Philine tincta A. E. Verrill, 1882 -- valid -- tinted paper-bubble, tinted paperbubble
  Philinidae Gray, 1850 -- valid
  Philinopsis Pease, 1860 -- valid
  Philinopsis pusa (Ev. Marcus and Er. Marcus, 1967) -- valid -- pusa aglaja
  Philippia J. E. Gray, 1847 -- valid
  Philippia hybrida (Linnaeus, 1758) -- valid
  Philobrya Carpenter, 1872 -- valid
  Philobrya setosa (Carpenter, 1864) -- valid -- hairy philobrya
  Philobryidae F. Bernard, 1897 -- valid
  Philomycidae Gray, 1847 -- valid
  Philomycus Rafinesque, 1820 -- valid
  Philomycus batchi Branson, 1968 -- valid -- dusky mantleslug
  Philomycus bisdosus Branson, 1968 -- valid -- grayfoot mantleslug
  Philomycus carolinianus (Bosc, 1802) -- valid -- Carolina mantleslug
  Philomycus flexuolaris Rafinesque, 1820 -- valid -- winding mantleslug
  Philomycus sellatus Hubricht, 1972 -- valid -- Alabama mantleslug
  Philomycus togatus (Gould, 1841) -- valid -- toga mantleslug
  Philomycus venustus Hubricht, 1953 -- valid -- brown-spotted mantleslug
  Philomycus virginicus Hubricht, 1953 -- valid -- Virginia mantleslug
  Pholadidae Lamarck, 1809 -- valid
  Pholadomyidae King, 1844 -- valid
  Pholadomyoida -- invalid
  Pholas Linnaeus, 1758 -- valid
  Pholas campechiensis Gmelin, 1791 -- valid -- Campeche angelwing
  Phreatoceras Hershler and Longley, 1987 -- valid
  Phreatoceras taylori (Hershler and Longley, 1986) -- valid -- Nymph Trumpet
  Phreatodrobia Hershler and Longley, 1986 -- valid
  Phreatodrobia conica Hershler and Longley, 1986 -- valid -- Hueco Cavesnail
  Phreatodrobia coronae Hershler and Longley, 1987 -- valid -- Crowned Cavesnail
  Phreatodrobia imitata Hershler and Longley, 1986 -- valid -- Mimic Cavesnail
  Phreatodrobia micra (Pilsbry and Ferriss, 1906) -- valid -- Flattened Cavesnail
  Phreatodrobia nugax (Pilsbry and Ferriss, 1906) -- valid -- Domed Cavesnail
  Phreatodrobia plana Hershler and Longley, 1986 -- valid -- Disc Cavesnail
  Phreatodrobia punctata Hershler and Longley, 1986 -- valid -- High-hat Cavesnail
  Phreatodrobia rotunda Hershler and Longley, 1986 -- valid -- Beaked Cavesnail
  Phyllaplysia P. Fischer, 1872 -- valid
  Phyllaplysia engeli Er. Marcus, 1955 -- valid -- turtlegrass seahare
  Phyllaplysia smaragda K. B. Clark, 1977 -- valid -- emerald leafslug
  Phyllaplysia taylori Dall, 1900 -- valid -- zebra leafslug
  Phyllidiidae Rafinesque, 1814 -- valid
  Phyllidiopsis Bergh, 1875 -- valid
  Phyllidiopsis blanca Gosliner and Behrens, 1988 -- valid
  Phylliroe Peron and Lesueur, 1810 -- valid
  Phylliroe atlantica Bergh, 1871 -- valid
  Phylliroe bucephalum Peron and Lesueur, 1810 -- valid
  Phylliroidae Menke, 1830 -- valid
  Phyllonotus Swainson, 1833 -- invalid
  Phyllonotus pomum (Gmelin, 1791) -- invalid -- apple murex
  Physa Draparnaud, 1801 -- valid
  Physa jennessi Dall, 1919 -- valid -- Obtuse Physa
  Physa megalochlamys Taylor, 1988 -- valid -- Cloaked Physa
  Physa natricina Taylor, 1988 -- valid -- Snake River Physa
  Physa siberica Westerlund, 1876 -- valid -- Frigid Physa
  Physa skinneri Taylor, 1954 -- valid -- Glass Physa
  Physa vernalis Taylor and Jokinen, 1984 -- valid -- Vernal Physa
  Physella Haldeman, 1842 -- valid
  Physella acuta (Draparnaud, 1805) -- valid -- European physa
  Physella ancillaria (Say, 1825) -- valid -- Pumpkin Physa
  Physella bermudezi (Aguayo, 1935) -- valid -- Lowdome Physa
  Physella bottimeri (Clench, 1924) -- valid -- Comanche Physa
  Physella boucardi (Crosse and P. Fischer, 1881) -- valid -- Desert Physa
  Physella columbiana (Hemphill, 1890) -- valid -- Rotund Physa
  Physella conoidea (P. Fischer and Crosse, 1886) -- valid -- Texas Physa
  Physella cooperi (Tryon, 1865) -- valid -- Olive Physa
  Physella costata (Newcomb, 1861) -- valid -- Ornate Physa
  Physella cubensis (Pfeiffer, 1839) -- valid -- Carib Physa
  Physella globosa (Haldeman, 1841) -- valid -- Globose Physa
  Physella gyrina (Say, 1821) -- valid -- Tadpole Physa
  Physella hendersoni (Clench, 1925) -- valid -- Bayou Physa
  Physella heterostropha (Say, 1817) -- valid -- Pewter Physa
  Physella hordacea (Lea, 1864) -- valid -- Grain Physa
  Physella humerosa (Gould, 1855) -- valid -- Corkscrew Physa
  Physella integra (Haldeman, 1841) -- valid -- Ashy Physa
  Physella johnsoni (Clench, 1926) -- valid -- Banff Springs Physa
  Physella lordi (Baird, 1863) -- valid -- Twisted Physa
  Physella magnalacustris (Walker, 1901) -- valid -- Great Lakes Physa
  Physella mexicana (Philippi, 1841) -- valid -- Polished Physa
  Physella microstriata (Chamberlin and E. G. Berry, 1930) -- valid -- Fish Lake Physa
  Physella osculans (Haldeman, 1841) -- valid -- Cayuse Physa
  Physella parkeri (Currier, 1881) -- valid -- Broadshoulder Physa
  Physella propinqua (Tryon, 1865) -- valid -- Rocky Mountain Physa
  Physella spelunca (Turner and Clench, 1974) -- valid -- Cave Physa
  Physella squalida (Morelet, 1851) -- valid -- Squalid Physa
  Physella traski (Lea, 1864) -- valid -- Sculpted Physa
  Physella utahensis (Clench, 1925) -- valid -- Utah Physa
  Physella vinosa (Gould, 1848) -- valid -- Banded Physa
  Physella virgata (Gould, 1855) -- valid -- Protean Physa
  Physella virginea (Gould, 1847) -- valid -- Sunset Physa
  Physella wrighti Te and Clarke, 1985 -- valid -- Hotwater Physa
  Physella zionis (Pilsbry, 1926) -- valid -- Wet-rock Physa
  Physidae Fitzinger, 1833 -- valid
  Pickworthiidae Iredale, 1917 -- valid
  Piliscus Loven, 1859 -- valid
  Piliscus commodus (Middendorff, 1851) -- valid
  Pilsbryna H. B. Baker, 1929 -- valid
  Pilsbryna aurea H. B. Baker, 1929 -- valid -- ornate bud
  Pilsbryna castanea H. B. Baker, 1931 -- valid -- prominent bud
  Pilsbryspira Bartsch, 1950 -- valid
  Pilsbryspira albocincta (C. B. Adams, 1845) -- valid
  Pilsbryspira albomaculata (d'Orbigny, 1842) -- valid -- white-band drillia
  Pilsbryspira jayana (C. B. Adams, 1850) -- valid
  Pilsbryspira leucocyma (Dall, 1884) -- valid -- white-knob drillia
  Pilsbryspira monilis (Bartsch and Rehder, 1939) -- valid
  Pilsbryspira zebroides (Weinkauff, 1876) -- valid
  Pinctada Roding, 1798 -- valid
  Pinctada imbricata Roding, 1798 -- valid -- Atlantic pearl-oyster
  Pinctada margaritifera (Linnaeus, 1758) -- valid -- Pacific pearl-oyster
  Pinna Linnaeus, 1758 -- valid
  Pinna carnea Gmelin, 1791 -- valid -- amber penshell
  Pinnidae Leach, 1819 -- valid
  Pisania Bivona-Bernardi, 1832 -- valid
  Pisania auritula (Link, 1807) -- invalid -- gaudy cantharus
  Pisania pusio (Linnaeus, 1758) -- valid -- miniature trumpet triton
  Pisania tincta (Conrad, 1846) -- invalid -- tinted cantharus
  Pisidium L. Pfeiffer, 1821 -- valid
  Pisidium adamsi Stimpson, 1851 -- valid -- Adam peaclam
  Pisidium amnicum (Muller, 1774) -- valid -- greater European peaclam
  Pisidium casertanum (Poli, 1791) -- valid -- ubiquitous peaclam
  Pisidium compressum Prime, 1852 -- valid -- ridged-beak peaclam, ridgebeak peaclam
  Pisidium conventus Clessin, 1877 -- valid -- Alpine peaclam
  Pisidium cruciatum Sterki, 1895 -- valid -- ornamented peaclam
  Pisidium dubium (Say, 1817) -- valid -- greater eastern peaclam
  Pisidium equilaterale Prime, 1852 -- valid -- round peaclam
  Pisidium fallax Sterki, 1896 -- valid -- river peaclam
  Pisidium ferrugineum Prime, 1852 -- valid -- rusty peaclam
  Pisidium henslowanum (Sheppard, 1825) -- valid -- Henslow peaclam
  Pisidium idahoense E. W. Roper, 1890 -- valid -- giant northern peaclam
  Pisidium insigne Gabb, 1868 -- valid -- tiny peaclam
  Pisidium lilljeborgi (Clessin, 1886) -- valid -- Lilljeborg peaclam
  Pisidium milium Held, 1836 -- valid -- quadrangular pillclam
  Pisidium nitidum Jenyns, 1832 -- valid -- shiny peaclam
  Pisidium punctatum Sterki, 1895 -- valid -- perforated peaclam
  Pisidium punctiferum (Guppy, 1867) -- valid -- striate peaclam
  Pisidium rotundatum Prime, 1852 -- valid -- fat peaclam
  Pisidium sanguinichristi Taylor, 1987 -- valid -- Sangre de Cristo peaclam
  Pisidium subtruncatum Malm, 1855 -- valid -- short-ended peaclam, shortended peaclam
  Pisidium supinum Schmidt, 1850 -- valid -- humpbacked peaclam
  Pisidium ultramontanum Prime, 1865 -- valid -- montane peaclam
  Pisidium variabile Prime, 1852 -- valid -- triangular peaclam
  Pisidium ventricosum Prime, 1851 -- valid -- globular peaclam
  Pisidium walkeri Sterki, 1895 -- valid -- Walker peaclam
  Pitar Römer, 1857 -- valid
  Pitar albidus (Gmelin, 1791) -- valid -- white pitar
  Pitar arestus (Dall and Simpson, 1901) -- valid -- pleasing pitar
  Pitar cordatus (Schwengel, 1951) -- valid -- Schwengel pitar, corded pitar
  Pitar fulminatus (Menke, 1828) -- valid -- lightning pitar
  Pitar morrhuanus (Linsley, 1848) -- valid -- false quahog
  Pitar newcombianus (Gabb, 1865) -- valid -- Newcomb pitar
  Pitar pilula Rehder, 1943 -- valid -- little-pill pitar
  Pitar simpsoni (Dall, 1895) -- valid -- Simpson pitar, chalky pitar
  Pitar zonatus (Dall, 1902) -- valid -- banded pitar
  Placiphorella Dall, 1879 -- valid -- boreal veiled chiton
  Placiphorella atlantica (A. E. Verrill and S. Smith, 1882) -- valid
  Placiphorella borealis Pilsbry, 1893 -- valid -- boreal veiled chiton
  Placiphorella mirabilis R. N. Clark, 1994 -- valid
  Placiphorella pacifica S. S. Berry, 1919 -- invalid
  Placiphorella rufa S. S. Berry, 1917 -- valid -- red veiled chiton
  Placiphorella stimpsoni (Gould, 1859) -- valid
  Placiphorella velata Dall, 1879 -- valid -- veiled chiton
  Placopecten Verrill, 1897 -- valid
  Placopecten magellanicus (Gmelin, 1791) -- valid -- sea scallop
  Planaxidae Gray, 1850 -- valid
  Planktomya Simroth, 1896 -- valid
  Planktomya henseni Simroth, 1896 -- valid -- planktonic sportellid
  Planogyra E. S. Morse, 1864 -- valid
  Planogyra asteriscus (E. S. Morse, 1857) -- valid -- eastern flat-whorl
  Planogyra clappi (Pilsbry, 1898) -- valid -- western flat-whorl
  Planorbella Haldeman, 1842 -- valid
  Planorbella ammon (Gould, 1855) -- valid -- Jupiter Rams-horn, Jupiter Ramshorn
  Planorbella armigera (Say, 1821) -- invalid -- thicklip rams-horn
  Planorbella binneyi (Tryon, 1867) -- valid -- Coarse Rams-horn, Coarse Ramshorn
  Planorbella campanulata (Say, 1821) -- valid -- Bellmouth Rams-horn, Bellmouth Ramshorn
  Planorbella campestris (Dawson, 1875) -- invalid -- meadow rams-horn
  Planorbella columbiensis (F. C. Baker, 1945) -- valid -- Caribou Rams-horn, Caribou Ramshorn
  Planorbella corpulenta (Say, 1824) -- valid -- Corpulent Rams-horn, Corpulent Ramshorn
  Planorbella duryi (Wetherby, 1879) -- valid -- Seminole Rams-horn, Seminole Ramshorn
  Planorbella magnifica (Pilsbry, 1903) -- valid -- Magnificent Rams-horn, Magnificent Ramshorn
  Planorbella multivolvis (Case, 1847) -- valid -- Acorn Rams-horn, Acorn Ramshorn
  Planorbella occidentalis (J. G. Cooper, 1870) -- valid -- Fine-lined Rams-horn
  Planorbella oregonensis (Tryon, 1865) -- valid -- Lamb Rams-horn, Lamb Ramshorn
  Planorbella pilsbryi (F. C. Baker, 1926) -- valid -- file rams-horn, File Ramshorn
  Planorbella scalaris (Jay, 1839) -- valid -- Mesa Rams-horn, Mesa Ramshorn
  Planorbella subcrenata (Carpenter, 1857) -- valid -- Rough Rams-horn, Rough Ramshorn
  Planorbella tenuis (Dunker, 1850) -- valid -- Mexican Rams-horn, Mexican Ramshorn
  Planorbella traski (Lea, 1856) -- valid -- Keeled Rams-horn, Keeled Ramshorn
  Planorbella trivolvis (Say, 1817) -- valid -- marsh rams-horn, Marsh Ramshorn
  Planorbella truncata (M. Miles, 1861) -- valid -- Druid Rams-horn, Druid Ramshorn
  Planorbidae Rafinesque, 1815 -- valid
  Planorbula Haldeman, 1842 -- valid
  Planorbula armigera (Say, 1821) -- valid -- Thicklip Rams-horn, Thicklip Ramshorn, Thick-lipped Rams-horn
  Platomysia meroea (Carpenter, 1864) -- invalid -- broad lepton
  Platycythara Woodring, 1928 -- valid
  Platycythara elata (Dall, 1889) -- valid
  Platydorididae Bergh, 1891 -- invalid
  Platydoris Bergh, 1877 -- valid
  Platydoris angustipes (Morch, 1863) -- valid
  Platydoris macfarlandi Hanna, 1951 -- valid -- California flat doris
  Platyodon Conrad, 1837 -- valid
  Platyodon cancellatus (Conrad, 1837) -- valid -- boring softshell clam, boring softshell
  Plectodon Carpenter, 1864 -- valid
  Plectodon granulatus (Dall, 1881) -- valid -- grainy plectodon
  Plectodon scaber Carpenter, 1864 -- valid -- rough plectodon
  Plectomerus Conrad, 1853 -- valid
  Plectomerus dombeyanus (Valenciennes in Humboldt & Bonpland, 1827) -- valid -- bankclimber
  Plesiocystiscus Coovert and Coovert, 1995 -- valid
  Plesiocystiscus jewettii (Carpenter, 1856) -- valid
  Plesiocystiscus myrmecoon (Dall, 1919) -- valid
  Plesiocystiscus politulus (Dall, 1919) -- valid -- polite marginella
  Plethobasus Simpson, 1900 -- valid
  Plethobasus cicatricosus (Say, 1829) -- valid -- white wartyback, white wartyback pearly mussel
  Plethobasus cooperianus (Lea, 1834) -- valid -- orange-footed pearly mussel, orangefoot pimpleback
  Plethobasus cyphyus (Rafinesque, 1820) -- valid -- sheepnose
  Pleurobema Rafinesque, 1819 -- valid
  Pleurobema altum (Conrad, 1854) -- invalid -- highnut
  Pleurobema avellanum Simpson, 1900 -- invalid -- hazel pigtoe
  Pleurobema beadleianum (Lea, 1861) -- valid -- Mississippi pigtoe
  Pleurobema bournianum (Lea, 1840) -- invalid -- Scioto pigtoe
  Pleurobema chattanoogaense (Lea, 1858) -- invalid -- painted clubshell
  Pleurobema clava (Lamarck, 1819) -- valid -- clubshell
  Pleurobema coccineum (Conrad, 1836) -- invalid -- round pigtoe
  Pleurobema collina (Conrad, 1837) -- invalid -- James River spinymussel, James spinymussel, Virginia spinymussel
  Pleurobema cordatum (Rafinesque, 1820) -- valid -- Ohio pigtoe
  Pleurobema curtum (Lea, 1859) -- valid -- black clubshell, Curtus' mussel
  Pleurobema decisum (Lea, 1831) -- valid -- southern clubshell
  Pleurobema flavidulum (Lea, 1861) -- invalid -- yellow pigtoe
  Pleurobema furvum (Conrad, 1834) -- invalid -- dark pigtoe
  Pleurobema georgianum (Lea, 1841) -- valid -- southern pigtoe
  Pleurobema gibberum (Lea, 1838) -- invalid -- Cumberland pigtoe, Cumberland pigtoe mussel
  Pleurobema hagleri (Frierson, 1900) -- invalid -- brown pigtoe
  Pleurobema hanleyianum (Lea, 1852) -- valid -- Georgia pigtoe
  Pleurobema johannis (Lea, 1859) -- invalid -- Alabama pigtoe
  Pleurobema marshalli Frierson, 1927 -- valid -- flat pigtoe, Marshall's mussel
  Pleurobema murrayense (Lea, 1868) -- invalid -- Coosa pigtoe
  Pleurobema nucleopsis (Conrad, 1849) -- invalid -- longnut
  Pleurobema oviforme (Conrad, 1834) -- valid -- Tennessee clubshell
  Pleurobema perovatum (Conrad, 1834) -- valid -- ovate clubshell
  Pleurobema plenum (Lea, 1840) -- valid -- rough pigtoe
  Pleurobema pyramidatum (Lea, 1831) -- invalid -- pyramid pigtoe
  Pleurobema pyriforme (Lea, 1857) -- valid -- oval pigtoe
  Pleurobema riddellii (Lea, 1862) -- valid -- Louisiana pigtoe
  Pleurobema rubellum (Conrad, 1834) -- valid -- Warrior pigtoe
  Pleurobema rubrum (Rafinesque, 1820) -- valid -- pyramid pigtoe
  Pleurobema sintoxia (Rafinesque, 1820) -- valid -- round pigtoe
  Pleurobema strodeanum (B. H. Wright, 1898) -- valid -- fuzzy pigtoe
  Pleurobema taitianum (Lea, 1834) -- valid -- heavy pigtoe, Judge Tait's mussel
  Pleurobema troschelianum (Lea, 1852) -- invalid -- Alabama clubshell
  Pleurobema verum (Lea, 1861) -- valid -- true pigtoe
  Pleurobranchaea Meckel, 1813 -- valid
  Pleurobranchaea bonnieae Ev. Marcus and Gosliner, 1984 -- valid
  Pleurobranchaea californica MacFarland, 1966 -- valid
  Pleurobranchaea inconspicua Bergh, 1897 -- valid
  Pleurobranchaea tarda A. E. Verrill, 1880 -- valid
  Pleurobranchidae Menke, 1828 -- invalid
  Pleurobranchus Cuvier, 1804 -- valid
  Pleurobranchus areolatus Morch, 1863 -- valid -- Atlantic sidegill slug
  Pleurobranchus reesi White, 1952 -- valid
  Pleurocera Rafinesque, 1818 -- valid
  Pleurocera acuta Rafinesque, 1831 -- valid -- Sharp Hornsnail
  Pleurocera alveare (Conrad, 1834) -- valid -- Rugged Hornsnail
  Pleurocera annulifera (Conrad, 1834) -- valid -- Ringed Hornsnail
  Pleurocera brumbyi (Lea, 1852) -- valid -- Spiral Hornsnail
  Pleurocera canaliculata (Say, 1821) -- valid -- Silty Hornsnail
  Pleurocera corpulenta (Anthony, 1854) -- valid -- Corpulent Hornsnail
  Pleurocera curta (Haldeman, 1841) -- valid -- Shortspire Hornsnail
  Pleurocera foremani (Lea, 1843) -- valid -- Rough Hornsnail
  Pleurocera gradata (Anthony, 1854) -- valid -- Bottle Hornsnail
  Pleurocera nobilis (Lea, 1845) -- valid -- Noble Hornsnail
  Pleurocera parva (Lea, 1862) -- valid -- Dainty Hornsnail
  Pleurocera postelli (Lea, 1862) -- valid -- Broken Hornsnail
  Pleurocera prasinata (Conrad, 1834) -- valid -- Smooth Hornsnail
  Pleurocera pyrenella (Conrad, 1834) -- valid -- Skirted Hornsnail
  Pleurocera showalteri (Lea, 1862) -- valid -- Upland Hornsnail
  Pleurocera trochiformis (Conrad, 1834) -- valid -- Sulcate Hornsnail
  Pleurocera uncialis (Haldeman, 1841) -- valid -- Pagoda Hornsnail
  Pleurocera vestita (Conrad, 1834) -- valid -- Brook Hornsnail
  Pleurocera walkeri Goodrich, 1928 -- valid -- Telescope Hornsnail
  Pleuroceridae P. Fischer, 1885 -- valid
  Pleuromalaxis Pilsbry and McGinty, 1945 -- valid
  Pleuromalaxis balesi (Pilsbry and McGinty, 1945) -- valid
  Pleuromeris Conrad, 1867 -- valid
  Pleuromeris armilla (Dall, 1903) -- valid -- armlet carditid
  Pleuromeris tridentata (Say, 1826) -- valid -- three-tooth carditid, threetooth carditid
  Pleuroploca P. Fischer, 1884 -- valid
  Pleuroploca gigantea (Kiener, 1840) -- valid -- horse conch
  Pleurotomariidae Swainson, 1840 -- valid
  Pleurotomella Verrill, 1872 -- valid
  Pleurotomella blakeana (Dall, 1889) -- valid
  Pleurotomella packardii A. E. Verrill, 1872 -- valid
  Plicatula Lamarck, 1801 -- valid
  Plicatula gibbosa Lamarck, 1801 -- valid -- Atlantic kittenpaw
  Plicatulidae Watson, 1930 -- invalid
  Plicifusus Dall, 1902 -- valid
  Plicifusus (Retifusus) Dall, 1916 -- invalid
  Plicifusus arcticus (Philippi, 1850) -- invalid -- Arctic whelk
  Plicifusus brunneus (Dall, 1877) -- invalid -- brown whelk
  Plicifusus griseus (Dall, 1890) -- invalid -- gray whelk
  Plicifusus incisus Dall, 1919 -- invalid
  Plicifusus johanseni Dall, 1919 -- invalid
  Plicifusus kroyeri (Möller, 1842) -- invalid
  Plicifusus laticordatus (Dall, 1907) -- invalid -- broad-cord whelk
  Plicifusus oceanodromae Dall, 1919 -- invalid -- seahorse whelk
  Plicifusus syrtensis (Packard, 1867) -- invalid
  Plicifusus verkruzeni (Kobelt, 1876) -- invalid
  Plicifusus virens (Dall, 1877) -- invalid -- green whelk
  Plicopurpura Cossmann, 1903 -- valid
  Plicopurpura patula (Linnaeus, 1758) -- valid -- widemouth rocksnail
  Pneumoderma atlanticum (Oken, 1815) -- invalid
  Pneumoderma atlanticum atlanticum (Oken, 1815) -- invalid
  Pneumoderma atlanticum pacificum Dall, 1872 -- invalid
  Pneumoderma mediterraneum (van Beneden, 1838) -- valid
  Pneumoderma violaceum (d'Orbigny, 1836) -- valid
  Pneumoderma violaceum pacificum Dall, 1871 -- valid
  Pneumoderma violaceum violaceum (d'Orbigny, 1836) -- valid
  Pneumodermatidae Latrielle, 1825 -- valid
  Pneumodermopsis macrochira (Meisenheimer, 1905) -- valid
  Pneumodermopsis paucidens (Boas, 1886) -- valid
  Pododesmus Philippi, 1837 -- valid
  Pododesmus cepio (J. E. Gray, 1850) -- invalid -- pacific false jingle
  Pododesmus macrochisma (Deshayes, 1839) -- valid -- alaska jingle
  Pododesmus pernoides (J. E. Gray, 1853) -- valid -- pedestal falsejingle, brown falsejingle
  Pododesmus rudis (Broderip, 1834) -- valid -- Atlantic falsejingle
  Poirieria Jousseaume, 1880 -- valid
  Poirieria bowdenensis E. H. Vokes, 1970 -- valid
  Poirieria nuttingi (Dall, 1896) -- valid
  Poirieria pazi (Crosse, 1869) -- valid
  Poirieria stimpsonii (Dall, 1889) -- valid
  Policordia Dall, Bartsch and Rehder, 1938 -- valid
  Policordia gemma (A. E. Verrill, 1880) -- valid -- sculptureless verticord
  Polinices Montfort, 1810 -- valid
  Polinices altus Arnold, 1903 -- invalid
  Polinices draconis (Dall, 1903) -- valid
  Polinices hepaticus (Roding, 1798) -- valid -- brown moonsnail
  Polinices immaculatus (Totten, 1835) -- invalid
  Polinices lacteus (Guilding, 1834) -- valid -- milk moonsnail
  Polinices lewisii (Gould, 1847) -- invalid
  Polinices pallidus (Broderip and G. B. Sowerby I, 1829) -- invalid -- pale moonsnail
  Polinices reclusianus (Deshayes, 1839) -- invalid -- tall moonsnail
  Polinices triseriata Say, 1826 -- invalid
  Polinices uberinus (d'Orbigny, 1842) -- valid -- dwarf white moonsnail, white moonsnail
  Pollia J. E. Gray, 1834 -- valid
  Pollia auritula (Link, 1807) -- valid -- gaudy cantharus
  Pollia karinae (Nowell-Usticke, 1959) -- valid
  Pollia tincta Conrad, 1846 -- valid -- tinted cantharus
  Polybranchia Pease, 1860 -- valid
  Polybranchia viridis (Deshayes, 1857) -- valid
  Polycera Cuvier, 1817 -- valid
  Polycera atra MacFarland, 1905 -- valid -- orange-spike polycera
  Polycera aurisula Er. Marcus, 1957 -- valid
  Polycera chilluna Er. Marcus, 1961 -- valid -- harlequin
  Polycera hedgpethi Er. Marcus, 1964 -- valid
  Polycera hummi Abbott, 1952 -- valid
  Polycera odhneri Er. Marcus, 1955 -- valid
  Polycera rycia Er. Marcus and Ev. Marcus, 1970 -- valid
  Polycera tricolor Robilliard, 1971 -- valid -- three-color polycera
  Polyceratidae Alder and Hancock, 1845 -- invalid
  Polycerella A. E. Verrill, 1881 -- valid
  Polycerella emertoni A. E. Verrill, 1881 -- valid
  Polycerella glandulosa Behrens and Gosliner, 1988 -- valid
  Polygireulima Sacco, 1892 -- valid
  Polygireulima rutila (Carpenter, 1866) -- valid -- auburn eulima
  Polygyra Say, 1818 -- valid
  Polygyra cereolus (Megerle von Muhlfeld, 1816) -- valid -- southern flatcoil
  Polygyra plana (Dunker, 1843) -- valid -- Bahama flatcoil
  Polygyra plana bahamensis Vanatta, 1919 -- valid -- Bahama flatcoil
  Polygyra septemvolva Say, 1818 -- valid -- Florida flatcoil
  Polygyrella W. G. Binney, 1863 -- valid
  Polygyrella polygyrella (Bland and J. G. Cooper, 1861) -- valid -- humped coin
  Polygyridae Pilsbry, 1895 -- valid
  Polygyriscus Pilsbry, 1948 -- valid
  Polygyriscus virginianus (P. R. Burch, 1947) -- valid -- virginia coil, virginia fringed mountain snail
  Polygyroidea Pilsbry, 1930 -- valid
  Polygyroidea harfordiana (J. G. Cooper, 1870) -- valid -- toothed coin
  Polymesoda Rafinesque, 1820 -- valid
  Polymesoda caroliniana (Bosc, 1801) -- valid -- Carolina marshclam
  Polymesoda maritima (d'Orbigny, 1842) -- valid -- southern marshclam
  Polyplacophora Blainvillle, 1816 -- valid -- chitons, polyplacophorans, chíton, poliplacoforo, quíton
  Polyschides agassizii (Dall, 1881) -- valid -- agassiz toothshell
  Polyschides californicus (Pilsbry and Sharp, 1898) -- valid -- California toothshell
  Polyschides carolinensis (Bush, 1885) -- valid -- Carolina toothshell
  Polyschides elongatus (J. B. Henderson, 1920) -- valid -- elongate toothshell
  Polyschides miamiensis (J. B. Henderson, 1920) -- valid -- Miami toothshell
  Polyschides pandionis (A. E. Verrill and S. Smith, 1880) -- valid -- kingly toothshell
  Polyschides parvus (J. B. Henderson, 1920) -- valid -- little toothshell
  Polyschides quadridentatus (Dall, 1881) -- valid -- four-tooth toothshell, fourtooth toothshell
  Polyschides rushii (Pilsbry and Sharp, 1898) -- valid -- rush toothshell
  Polyschides tetrodon (Pilsbry and Sharp, 1898) -- valid -- tetrodon toothshell
  Polystira Woodring, 1928 -- valid
  Polystira albida (G. Perry, 1811) -- valid -- white giant-turris
  Polystira florencae Bartsch, 1934 -- valid
  Polystira sunderlandi Petuch, 1987 -- valid
  Polystira tellea (Dall, 1889) -- valid -- delicate giant-turris
  Polystira vibex (Dall, 1889) -- valid -- twilled giant-turris
  Pomacea Perry, 1810 -- valid
  Pomacea bridgesi (Reeve, 1856) -- invalid -- Spiketopped Applesnail
  Pomacea canaliculata (Lamarck, 1822) -- valid -- Channeled Applesnail
  Pomacea haustrum (Reeve, 1858) -- valid -- Titan Applesnail
  Pomacea miamiensis Pilsbry, 1899 -- invalid
  Pomacea paludosa (Say, 1829) -- valid -- Florida Applesnail
  Pomatiopsidae Stimpson, 1865 -- valid
  Pomatiopsis Tryon, 1862 -- valid
  Pomatiopsis binneyi Tryon, 1863 -- valid -- Robust Walker
  Pomatiopsis californica Pilsbry, 1899 -- valid -- Pacific Walker
  Pomatiopsis chacei Pilsbry, 1937 -- valid -- Marsh Walker
  Pomatiopsis cincinnatiensis (Lea, 1840) -- valid -- Brown Walker
  Pomatiopsis hinkleyi Pilsbry, 1896 -- valid -- Tennessee River Walker
  Pomatiopsis lapidaria (Say, 1817) -- valid -- Slender Walker
  Popenaias popeii (Lea, 1857) -- valid -- Texas hornshell
  Popenais Frierson, 1927 -- invalid
  Popenais popeii (Lea, 1857) -- invalid -- Texas hornshell
  Poromya Forbes, 1844 -- valid
  Poromya albida Dall, 1886 -- valid -- white poromya
  Poromya granulata (Nyst and Westendorp, 1839) -- valid -- granular poromya
  Poromya houbricki Bernard, 1989 -- valid -- ovate poromya
  Poromya rostrata Rehder, 1943 -- valid -- rostrate poromya
  Poromyidae Dall, 1886 -- valid
  Portlandia Morch, 1857 -- valid
  Portlandia aestuariorum (Mosevich, 1928) -- valid
  Portlandia arctica (J. E. Gray, 1824) -- valid -- arctic nutclam, Arctic yoldia
  Portlandia intermedia (M. Sars, 1865) -- valid -- intermediate yoldia
  Portlandia lenticula (Moller, 1842) -- valid -- lenticulate yoldia
  Potamididae H. Adams and A. Adams, 1854 -- valid
  Potamilus Rafinesque, 1818 -- valid
  Potamilus alatus (Say, 1817) -- valid -- pink heelsplitter
  Potamilus amphichaenus (Frierson, 1898) -- valid -- Texas heelsplitter
  Potamilus capax (Green, 1832) -- valid -- fat pocketbook
  Potamilus inflatus (Lea, 1831) -- valid -- Alabama heelsplitter, inflated heelsplitter
  Potamilus ohiensis (Rafinesque, 1820) -- valid -- pink papershell
  Potamilus purpuratus (Lamarck, 1819) -- valid -- bleufer
  Potamocorbula Habe, 1955 -- valid
  Potamocorbula amurensis (Schrenck, 1861) -- valid -- brackish-water corbula
  Potamopyrgus Stimpson, 1865 -- valid
  Potamopyrgus antipodarum (J. E. Gray, 1853) -- valid -- New Zealand mud snail
  Praticolella von Martens, 1892 -- valid
  Praticolella bakeri Vanatta, 1915 -- valid -- orlando shrubsnail, ridge scrubsnail
  Praticolella berlandieriana (Moricand, 1833) -- valid -- shoulder-banded shrubsnail, banded scrubsnail
  Praticolella candida Hubricht, 1983 -- valid -- white shrubsnail, white scrubsnail
  Praticolella griseola (Pfeiffer, 1841) -- valid -- vera cruz shrubsnail, vagrant scrubsnail
  Praticolella jejuna (Say, 1821) -- valid -- florida shrubsnail
  Praticolella lawae (J. Lewis, 1874) -- valid -- appalachian shrubsnail, Appalachian scrubsnail
  Praticolella mobiliana (I. Lea, 1841) -- valid -- mobile shrubsnail, Choctaw scrubsnail
  Praticolella pachyloma (Menke, 1847) -- valid -- sandyland shrubsnail, sandyland scrubsnail
  Praticolella taeniata Pilsbry, 1940 -- valid -- many-banded shrubsnail, striped scrubsnail
  Praticolella trimatris Hubricht, 1983 -- valid -- hidalgo shrubsnail, Hidalgo scrubsnail
  Primovula Thiele, 1925 -- valid
  Primovula solemi Cate, 1973 -- valid -- robust miniovula
  Prionoglossa Tesch, 1950 -- valid
  Prionoglossa tetrabranchiata (Bonnevie, 1913) -- valid
  Pristes Carpenter, 1864 -- valid
  Pristes oblongus Carpenter, 1864 -- valid -- chiton clam
  Pristiloma Ancey, 1887 -- valid
  Pristiloma arcticum (Lehnert, 1884) -- valid -- northern tightcoil
  Pristiloma gabrielinum (S. S. Berry, 1924) -- valid -- waxy tightcoil
  Pristiloma idahoense Pilsbry, 1902 -- valid -- thin-lip tightcoil, thinlip tightcoil
  Pristiloma johnsoni (Dall, 1895) -- valid -- broadwhorl tightcoil
  Pristiloma juniperum A. G. Smith, 1957 -- valid -- cedar tightcoil, juniper tightcoil
  Pristiloma lansingi (Bland, 1875) -- valid -- denticulate tightcoil
  Pristiloma nicholsoni H. B. Baker, 1930 -- valid -- riparian tightcoil
  Pristiloma orotis (S. S. Berry, 1930) -- valid -- minute tightcoil
  Pristiloma pilsbryi Vanatta, 1899 -- valid -- crowned tightcoil
  Pristiloma shepardae (Hemphill, 1892) -- valid -- island tightcoil
  Pristiloma stearnsi (Bland, 1875) -- valid -- striate tightcoil
  Pristiloma wascoense (Hemphill, 1911) -- valid -- shiny tightcoil
  Pristinicola Hershler, Frest, Johannes, Bowler and F. G. Thompson, 1994 -- valid
  Pristinicola hemphilli (Pilsbry, 1890) -- valid -- Pristine Pyrg
  Probythinella Thiele, 1928 -- valid
  Probythinella emarginata (Kuster, 1852) -- valid -- Delta Hydrobe
  Probythinella protera Pilsbry, 1953 -- valid
  Prochaetodermatidae Salvini-Plawen, 1968 -- valid
  Promenetus F. C. Baker, 1935 -- valid
  Promenetus exacuous (Say, 1821) -- valid -- Sharp Sprite
  Promenetus umbilicatellus (Cockerell, 1887) -- valid -- Umbilicate Sprite
  Proneomenia Hubrecht, 1880 -- valid
  Proneomenia acuminata Heath, 1918 -- valid -- elongate solenogaster
  Proneomeniidae -- valid
  Propeamussidae Abbott, 1954 -- invalid
  Propeamussium Gregorio, 1884 -- valid
  Propeamussium cancellatum (E. A. Smith, 1885) -- valid -- acancellate glass-scallop, cancellate glass-scallop
  Propeamussium holmesii (Dall, 1886) -- valid -- Holmes glass-scallop
  Propeamussium pourtalesianum (Dall, 1886) -- valid -- Pourtales glass-scallop
  Propebela Iredale, 1918 -- valid
  Propebela alitakensis (Dall, 1919) -- valid
  Propebela angulosa (G. O. Sars, 1878) -- valid
  Propebela arctica (A. Adams, 1855) -- valid
  Propebela assimilis (G. O. Sars, 1878) -- valid
  Propebela concinnula (A. E. Verrill, 1882) -- valid
  Propebela exarata (Moller, 1842) -- valid
  Propebela fidicula (Gould, 1849) -- valid
  Propebela harpularia (Couthouy, 1838) -- valid
  Propebela mitrata (Dall, 1919) -- valid
  Propebela nobilis (Moller, 1842) -- valid
  Propebela popovia (Dall, 1919) -- valid
  Propebela rassina (Dall, 1919) -- valid
  Propebela rugulata (Moller, 1866) -- valid
  Propebela scalaris (Moller, 1842) -- valid
  Propebela turricula (Montagu, 1803) -- valid
  Prophysaon Bland and W. G. Binney, 1873 -- valid
  Prophysaon andersoni (J. G. Cooper, 1872) -- valid -- reticulate taildropper
  Prophysaon boreale Pilsbry, 1948 -- valid -- northern taildropper
  Prophysaon coeruleum Cockerell, 1890 -- valid -- blue-gray taildropper
  Prophysaon dubium Cockerell, 1890 -- valid -- papillose taildropper
  Prophysaon fasciatum Cockerell, 1890 -- valid -- banded taildropper
  Prophysaon foliolatum (Gould, 1851) -- valid -- yellow-bordered taildropper
  Prophysaon humile Cockerell, 1890 -- valid -- smoky taildropper
  Prophysaon obscurum Cockerell, 1890 -- valid -- mottled taildropper
  Prophysaon vanattae Pilsbry, 1948 -- valid -- scarletback taildropper
  Propilidium Forbes and Hanley, 1849 -- valid
  Propilidium lissocona (Dall, 1927) -- valid
  Propilidium reticulatum (A. E. Verrill, 1885) -- valid -- reticulate cocculina
  Propustularia Schilder, 1927 -- valid
  Propustularia surinamensis (G. Perry, 1811) -- valid -- Suriname cowrie
  Protatlanta Tesch, 1908 -- valid
  Protatlanta souleyeti (E. A. Smith, 1888) -- valid
  Proterato Schilder, 1927 -- valid
  Proterato gemma (Bavay, 1917) -- valid
  Proterato gemma pygmaea Schilder, 1933 -- valid
  Protothaca Dall, 1902 -- valid
  Protothaca granulata (Gmelin, 1791) -- valid -- beaded venus
  Protothaca laciniata (Carpenter, 1864) -- valid -- fringed littleneck, rough littleneck
  Protothaca staminea (Conrad, 1837) -- valid -- Pacific littleneck
  Protothaca tenerrima (Carpenter, 1857) -- valid -- thin-shell littleneck
  Prunum Herrmannsen, 1852 -- valid
  Prunum amabile (Redfield, 1852) -- valid -- queen marginella
  Prunum apicinum (Menke, 1828) -- valid -- common Atlantic marginella
  Prunum avenaceum (Deshayes, 1844) -- valid -- little oat marginella
  Prunum boreale (A. E. Verrill, 1884) -- valid -- boreal marginella
  Prunum carneum (Storer, 1837) -- valid -- orange marginella
  Prunum cassis (Dall, 1889) -- valid -- helmet marginella
  Prunum evelynae (Bayer, 1943) -- valid
  Prunum guttatum (Dillwyn, 1817) -- valid -- white-spot marginella
  Prunum nobilianum Bayer, 1943 -- valid -- courtly marginella
  Prunum roosevelti (Bartsch and Rehder, 1939) -- valid
  Prunum roscidum (Redfield, 1860) -- valid -- seaboard marginella
  Prunum succinea (Conrad, 1846) -- valid
  Prunum torticulum (Dall, 1881) -- valid -- knave marginella
  Prunum virginianum Conrad, 1868 -- valid -- Virginia marginella
  Prunum virginianum hartleyanum (Schwengel, 1941) -- valid -- Virginia marginella
  Prunum virginianum virginianum Conrad, 1868 -- valid -- Virginia marginella
  Psammobiidae J. Fleming, 1828 -- valid
  Psammodoris Martynov, 1994 -- valid
  Psammodoris thompsoni (Millen and Nybakken, 1987) -- valid
  Psephidia Dall, 1902 -- invalid
  Psephidia cymata Dall, 1913 -- invalid -- wavy dwarf-venus
  Psephidia ovalis Dall, 1902 -- invalid -- oval dwarf-venus
  Psephidia stephensae Hertlein and Grant, 1972 -- invalid -- Stephens dwarf-venus
  Pseudantalis stenoschizum (Pilsbry and Sharp, 1897) -- invalid -- narrow-slit tuskshell
  Pseudochama Odhner, 1917 -- valid
  Pseudochama exogyra (Conrad, 1837) -- valid -- Pacific jewelbox
  Pseudochama granti Strong, 1934 -- valid -- grant jewelbox, deep jewelbox
  Pseudochama inezae Bayer, 1943 -- valid -- inez jewelbox, alabaster jewelbox
  Pseudochama radians (Lamarck, 1819) -- valid -- Atlantic jewelbox
  Pseudococculinidae Hickman, 1983 -- valid
  Pseudocyphoma Cate, 1973 -- valid
  Pseudocyphoma gibbulum Cate, 1978 -- valid -- plump cyphoma
  Pseudocyphoma intermedium (G. B. Sowerby I, 1828) -- valid -- intermediate cyphoma
  Pseudodiala Ponder, 1967 -- valid
  Pseudodiala acuta (Carpenter, 1864) -- valid -- acute barleysnail
  Pseudomalaxis P. Fischer, 1885 -- valid
  Pseudomalaxis zanclaeus (Philippi, 1844) -- valid
  Pseudomelatoma Dall, 1918 -- valid
  Pseudomelatoma grippi (Dall, 1919) -- valid
  Pseudomelatoma penicillata (Carpenter, 1865) -- valid
  Pseudomelatoma sticta S. S. Berry, 1956 -- valid
  Pseudomelatoma torosa (Carpenter, 1864) -- valid
  Pseudomelatomidae Morrison, 1966 -- valid
  Pseudosabinella McLean, 1995 -- valid
  Pseudosabinella bakeri (Bartsch, 1917) -- valid
  Pseudoscilla Boettger, 1901 -- valid
  Pseudoscilla decorata (de Folin, 1873) -- valid
  Pseudosimnia Schilder, 1927 -- valid
  Pseudosimnia pyrifera Cate, 1973 -- valid -- pear simnia
  Pseudosimnia sphoni Cate, 1973 -- valid
  Pseudosimnia vanhyningi (M. Smith, 1940) -- valid
  Pseudostomatella Thiele, 1924 -- valid
  Pseudostomatella erythrocoma (Dall, 1889) -- valid -- false stomatella
  Pseudosubulina Strebel and Pfeffer, 1882 -- valid
  Pseudosubulina cheatumi Pilsbry, 1950 -- valid -- Chisos foxsnail
  Pseudosuccinea F. C. Baker, 1908 -- valid
  Pseudosuccinea columella (Say, 1817) -- valid -- Mimic Lymnaea, Mimic Pondsnail
  Pseudotaranis McLean, 1995 -- valid
  Pseudotaranis hyperia (Dall, 1919) -- valid
  Pseudotaranis strongi (Arnold, 1903) -- valid
  Pseudotorinia Sacco, 1892 -- valid
  Pseudotorinia architae (O. G. Costa, 1841) -- valid -- noduled sundial
  Pseudotorinia bullisi Bieler, Merrill and Boss, 1985 -- valid
  Psilaxis Woodring, 1928 -- valid
  Psilaxis krebsii (Morch, 1875) -- valid -- smooth sundial
  Psilodens Salvini-Plawen, 1977 -- valid
  Psiloteredo Bartsch, 1922 -- valid
  Psiloteredo megotara (Hanley, 1848) -- valid -- big-ear shipworm
  Pteria Scoploi, 1777 -- valid
  Pteria colymbus (Roding, 1798) -- valid -- Atlantic wing-oyster
  Pteria longisquamosa (Dunker, 1852) -- valid -- scaly wing-oyster
  Pteria sterna (Gould, 1851) -- valid -- Pacific wing-oyster
  Pteria vitrea (Reeve, 1857) -- valid -- glassy wing-oyster
  Pteriidae Gray, 1847 -- valid
  Pterioida Newell, 1965 -- invalid
  Pteromeris Conrad, 1862 -- valid
  Pteromeris perplana (Conrad, 1841) -- valid -- flattened carditid
  Pteropurpura Jousseaume, 1880 -- valid
  Pteropurpura bequaerti (Clench and Perez Farfante, 1945) -- valid
  Pteropurpura festiva (Hinds, 1844) -- valid -- festive murex
  Pteropurpura macroptera (Deshayes, 1839) -- valid -- frill-wing murex
  Pteropurpura trialata (G. B. Sowerby II, 1834) -- valid -- western three-wing murex, three-wing murex
  Pteropurpura vokesae Emerson, 1964 -- valid -- wrinkle-wing murex
  Pterotrachea Forskal, 1775 -- valid
  Pterotrachea coronata Forskal, 1775 -- valid
  Pterotrachea hippocampus Philippi, 1836 -- valid
  Pterotrachea keraudrenii J. E. Gray, 1850 -- valid
  Pterotrachea scutata Gegenbaur, 1855 -- valid
  Pterotracheidae Gray, 1840 -- invalid
  Pterotyphis Jousseaume, 1881 -- valid
  Pterotyphis triangularis (A. Adams, 1855) -- valid
  Pterynotus Swainson, 1833 -- valid
  Pterynotus ariomus (Clench and Perez Farfante, 1945) -- valid
  Pterynotus phaneus (Dall, 1889) -- valid -- shining murex
  Ptychatractus Stimpson, 1865 -- valid
  Ptychatractus ligatus (Mighels and C. B. Adams, 1842) -- valid -- ligate false spindle
  Ptychatractus occidentalis Stearns, 1873 -- valid
  Ptychobranchus Simpson, 1900 -- valid
  Ptychobranchus fasciolaris (Rafinesque, 1820) -- valid -- kidneyshell
  Ptychobranchus greenii (Conrad, 1834) -- valid -- triangular kidneyshell
  Ptychobranchus jonesi (van der Schalie, 1934) -- valid -- southern kidneyshell
  Ptychobranchus occidentalis (Conrad, 1836) -- valid -- Ouachita kidneyshell
  Ptychobranchus subtentum (Say, 1825) -- invalid -- fluted kidneyshell
  Ptychosalpinx Gill, 1867 -- valid
  Ptychosalpinx globulus (Dall, 1889) -- valid -- globose whelk
  Puberella Fischer-Piette and Vukadinovic, 1977 -- valid
  Puberella intapurpurea (Conrad, 1849) -- valid -- lady-in-waiting venus
  Puberella pubera (Bory Saint-Vincent, 1827) -- valid -- downy venus
  Pugnus Hedley, 1896 -- valid
  Pugnus lachrimula (Gould, 1862) -- valid -- little teardrop marginella
  Pugnus serrei (Bavay, 1911) -- valid
  Pulsellidae Scarabino in Boss, 1982 -- valid
  Pulsellum lobatum (G. B. Sowerby II, 1860) -- valid -- lobate toothshell
  Pulsellum occidentale (J. B. Henderson, 1920) -- valid -- westerly toothshell
  Pulsellum salishorum E. Marshall, 1980 -- valid -- Salish toothshell
  Pulsellum verrilli (J. B. Henderson, 1920) -- valid
  Punctidae Morse, 1864 -- valid
  Punctum E. S. Morse, 1864 -- valid
  Punctum blandianum Pilsbry, 1900 -- valid -- brown spot
  Punctum californicum Pilsbry, 1898 -- valid -- ribbed spot
  Punctum hannai Roth, 1985 -- valid -- Trinity spot
  Punctum minutissimum (I. Lea, 1841) -- valid -- small spot
  Punctum randolphi (Dall, 1895) -- valid -- conical spot
  Punctum smithi Morrison, 1935 -- valid -- lamellate spot
  Punctum vitreum (H. B. Baker, 1930) -- valid -- glass spot
  Puncturella R. T. Lowe, 1827 -- valid
  Puncturella caryophylla Dall, 1914 -- valid -- clove puncturella
  Puncturella cooperi Carpenter, 1864 -- valid
  Puncturella galeata (Gould, 1846) -- valid -- helmet puncturella
  Puncturella longifissa Dall, 1914 -- valid -- long-slot puncturella
  Puncturella noachina (Linnaeus, 1771) -- valid -- diluvian puncturella
  Puncturella punctocostata S. S. Berry, 1947 -- valid -- dot-rib puncturella
  Puncturella sportella Watson, 1882 -- valid
  Puperita Gray, 1857 -- valid
  Puperita pupa (Linnaeus, 1767) -- valid -- zebra nerite
  Pupilla Leach, 1828 -- valid
  Pupilla blandi E. S. Morse, 1865 -- valid -- Rocky Mountain column
  Pupilla hebes (Ancey, 1881) -- valid -- crestless column
  Pupilla muscorum (Linnaeus, 1758) -- valid -- widespread column
  Pupilla sonorana (Sterki, 1899) -- valid -- three-tooth column
  Pupilla syngenes (Pilsbry, 1890) -- valid -- top-heavy column
  Pupillidae Turton, 1831 -- valid
  Pupisoma Stoliczka, 1873 -- valid
  Pupisoma dioscoricola (C. B. Adams, 1845) -- valid -- yam babybody
  Pupisoma macneilli (G. H. Clapp, 1918) -- valid -- Gulf babybody
  Pupisoma minus Pilsbry, 1920 -- valid
  Pupoides L. Pfeiffer, 1854 -- valid
  Pupoides albilabris (C. B. Adams, 1841) -- valid -- white-lip dagger
  Pupoides hordaceus (Gabb, 1866) -- valid -- ribbed dagger
  Pupoides inornatus Vanatta, 1915 -- valid -- Rocky Mountain dagger
  Pupoides modicus (Gould, 1848) -- valid -- island dagger
  Pusula Jousseaume, 1884 -- valid
  Pusula californiana (J. E. Gray, 1827) -- valid -- California trivia
  Pusula californica (G. B. Sowerby II, 1832) -- valid
  Pusula maltbiana (Schwengel and McGinty, 1942) -- valid
  Pusula padreserrai Cate, 1979 -- valid
  Pyganodon Crosse & Fischer, 1894 -- valid
  Pyganodon cataracta (Say, 1817) -- valid -- eastern floater
  Pyganodon fragilis (Lamarck, 1819) -- valid -- Newfoundland floater
  Pyganodon gibbosa (Say, 1824) -- valid -- inflated floater
  Pyganodon grandis (Say, 1829) -- valid -- giant floater
  Pyganodon lacustris (Lea, 1857) -- valid -- lake floater
  Pyramidella Lamarck, 1799 -- valid
  Pyramidella adamsi (Carpenter, 1864) -- valid
  Pyramidella candida Morch, 1875 -- valid
  Pyramidella crenulata (Holmes, 1860) -- valid
  Pyramidella dolabrata (Linnaeus, 1758) -- valid
  Pyramidella mazatlantica Dall and Bartsch, 1909 -- valid
  Pyramidella mexicana Dall and Bartsch, 1909 -- valid
  Pyramidella resticula (Dall, 1889) -- valid
  Pyramidellidae Gray, 1840 -- valid
  Pyrgocythara Woodring, 1928 -- valid
  Pyrgocythara balteata (Reeve, 1846) -- valid
  Pyrgocythara filosa Rehder, 1943 -- valid -- filose mangelia
  Pyrgocythara hemphilli Bartsch and Rehder, 1939 -- valid
  Pyrgocythara plicosa (C. B. Adams, 1850) -- valid -- plicate mangelia
  Pyrgophorus Ancey, 1888 -- valid
  Pyrgophorus parvulus (Guilding, 1828) -- valid
  Pyrgophorus platyrachis F. G. Thompson, 1968 -- valid -- Serrate Crownsnail, Serrated Crownsnail
  Pyrgophorus spinosus (Call and Pilsbry, 1886) -- valid -- Spiny Crownsnail
  Pyrgospira McLean, 1971 -- valid
  Pyrgospira ostrearum (Stearns, 1872) -- valid
  Pyrgospira tampaensis (Bartsch and Rehder, 1939) -- valid
  Pyrgulopsis Call and Pilsbry, 1886 -- valid
  Pyrgulopsis aardahli Hershler, 1989 -- valid -- Benton Valley Springsnail
  Pyrgulopsis agarhecta (F. G. Thompson, 1969) -- invalid -- Ocmulgee marstonia
  Pyrgulopsis amargosae Hershler, 1989 -- valid -- Amargosa Springsnail
  Pyrgulopsis arga (F. G. Thompson, 1977) -- invalid -- ghost marstonia
  Pyrgulopsis arizonae (Taylor, 1987) -- valid -- Apache Springsnail
  Pyrgulopsis avernalis (Pilsbry, 1935) -- valid -- Moapa Pebblesnail
  Pyrgulopsis bacchus Hershler, 1988 -- valid -- Grand Wash Springsnail
  Pyrgulopsis bernardina (Taylor, 1987) -- valid -- San Bernardino Springsnail
  Pyrgulopsis bruneauensis Hershler, 1990 -- valid -- Bruneau Hot Springsnail
  Pyrgulopsis bryantwalkeri Hershler, 1994 -- valid -- Cortez Hills Pebblesnail
  Pyrgulopsis californiensis (Gregg and Taylor, 1965) -- valid -- Laguna Mountain Springsnail
  Pyrgulopsis carinifera (Pilsbry, 1935) -- valid -- Moapa Valley Pyrg
  Pyrgulopsis castor (F. G. Thompson, 1977) -- invalid -- beaverpond marstonia
  Pyrgulopsis chupaderae Taylor, 1987 -- valid -- Chupadera Springsnail
  Pyrgulopsis conica Hershler, 1988 -- valid -- Kingman Springsnail
  Pyrgulopsis crystalis Hershler and Sada, 1987 -- valid -- Crystal Springsnail
  Pyrgulopsis davisi (Taylor, 1987) -- valid -- Limpia Creek Springsnail
  Pyrgulopsis deserta (Pilsbry, 1916) -- valid -- Desert Springsnail
  Pyrgulopsis diablensis Hershler, 1995 -- valid -- Diablo Range Pyrg
  Pyrgulopsis eremica Hershler, 1995 -- valid -- Smoke Creek Pyrg
  Pyrgulopsis erythropoma (Pilsbry, 1899) -- valid -- Ash Meadows Pebblesnail
  Pyrgulopsis fairbanksensis Hershler and Sada, 1987 -- valid -- Fairbanks Springsnail
  Pyrgulopsis gibba Hershler, 1995 -- valid -- Surprise Valley Pyrg
  Pyrgulopsis gilae (Taylor, 1987) -- valid -- Gila Springsnail
  Pyrgulopsis giuliani Hershler and Pratt, 1990 -- valid -- Southern Sierra Nevada Springsnail
  Pyrgulopsis glandulosa Hershler, 1988 -- valid -- Verde Rim Springsnail
  Pyrgulopsis greggi Hershler, 1995 -- valid -- Kern River Pyrg, Kern River Springsnail
  Pyrgulopsis halcyon (F. G. Thompson, 1977) -- invalid -- halcyon marstonia
  Pyrgulopsis hendersoni (Pilsbry, 1933) -- invalid -- Harney Lake springsnail
  Pyrgulopsis hershleri F. G. Thompson, 1995 -- invalid -- Coosa pyrg
  Pyrgulopsis idahoensis (Pilsbry, 1933) -- invalid -- Idaho springsnail
  Pyrgulopsis intermedia (Tryon, 1865) -- valid -- Crooked Creek Springsnail
  Pyrgulopsis isolata Hershler and Sada, 1987 -- valid -- Elongate-gland Springsnail
  Pyrgulopsis kolobensis (Taylor, 1987) -- valid -- Toquerville Springsnail
  Pyrgulopsis letsoni (Walker, 1901) -- invalid -- gravel pyrg
  Pyrgulopsis longae Hershler, 1995 -- valid -- Long Valley Pyrg
  Pyrgulopsis longinqua (Gould, 1855) -- valid -- Salton Sea Springsnail
  Pyrgulopsis lustrica (Pilsbry, 1890) -- invalid -- boreal marstonia
  Pyrgulopsis merriami (Pilsbry and Beecher, 1892) -- valid -- Pahranagat Pebblesnail
  Pyrgulopsis metcalfi (Taylor, 1987) -- valid -- Naegele Springsnail
  Pyrgulopsis micrococcus (Pilsbry, 1893) -- valid -- Oasis Valley Springsnail
  Pyrgulopsis montezumensis Hershler, 1988 -- valid -- Montezuma Well Springsnail
  Pyrgulopsis morrisoni Hershler, 1988 -- valid -- Page Springsnail
  Pyrgulopsis nanus Hershler and Sada, 1987 -- valid -- Distal-gland Springsnail
  Pyrgulopsis neomexicana (Pilsbry, 1916) -- valid -- Socorro Springsnail
  Pyrgulopsis nevadensis (Stearns, 1883) -- valid -- Corded Pyrg
  Pyrgulopsis ogmorhaphe (F. G. Thompson, 1977) -- invalid -- royal springsnail
  Pyrgulopsis olivacea (Pilsbry, 1895) -- invalid -- olive marstonia
  Pyrgulopsis owensensis Hershler, 1989 -- valid -- Owens Valley Springsnail
  Pyrgulopsis ozarkensis Hinkley, 1915 -- invalid -- Ozark pyrg
  Pyrgulopsis pachyta (F. G. Thompson, 1977) -- invalid -- armored marstonia
  Pyrgulopsis pecosensis (Taylor, 1987) -- valid -- Pecos Springsnail
  Pyrgulopsis perturbata Hershler, 1989 -- valid -- Fish Slough Springsnail
  Pyrgulopsis pilsbryana (J. L. Baily and R. I. Baily, 1952) -- valid -- Bear Lake Springsnail
  Pyrgulopsis pisteri Hershler and Sada, 1987 -- valid -- Median-gland Springsnail
  Pyrgulopsis robusta (Walker, 1908) -- valid -- Jackson Lake Springsnail
  Pyrgulopsis roswellensis (Taylor, 1987) -- valid -- Roswell Springsnail
  Pyrgulopsis scalariformis (Wolf, 1870) -- invalid -- moss pyrg
  Pyrgulopsis simplex Hershler, 1988 -- valid -- Fossil Springsnail
  Pyrgulopsis sola Hershler, 1988 -- valid -- Brown Springsnail
  Pyrgulopsis stearnsiana (Pilsbry, 1899) -- valid -- Yaqui Springsnail
  Pyrgulopsis taylori Hershler, 1995 -- valid -- San Luis Obispo Pyrg
  Pyrgulopsis thermalis (Taylor, 1987) -- valid -- New Mexico Hot Springsnail
  Pyrgulopsis thompsoni Hershler, 1988 -- valid -- Huachuca Springsnail
  Pyrgulopsis trivialis (Taylor, 1987) -- valid -- Black River Springsnail
  Pyrgulopsis ventricosa Hershler, 1995 -- valid -- Clear Lake Pyrg
  Pyrgulopsis wongi Hershler, 1989 -- valid -- Wong's Pyrg
  Pyrulofusus Mörch, 1857 -- valid
  Pyrulofusus deformis (Reeve, 1847) -- valid -- warped whelk
  Pyrulofusus dexius (Dall, 1907) -- valid
  Pyrulofusus harpa (Mörch, 1857) -- valid -- left-hand whelk
  Pyrulofusus melonis (Dall, 1891) -- valid
  Pyrunculus Pilsbry, 1895 -- valid
  Pyrunculus caelatus (Bush, 1885) -- valid -- engraved barrel-bubble
  Pyrunculus ovatus (Jeffreys, 1871) -- valid -- ovate barrel-bubble
  Pythenella Dall, 1899 -- invalid
  Pythenella cuneata (A. E. Verrill and Bush, 1898) -- invalid -- cuneate montacutid
  Pythinella Dall, 1899 -- valid
  Pythinella cuneata (A. E. Verrill and Bush, 1898) -- valid -- cuneate montacutid
  Quadrula Rafinesque, 1820 -- valid
  Quadrula apiculata (Say, 1829) -- invalid -- southern mapleleaf
  Quadrula asperata (Lea, 1861) -- invalid -- Alabama orb
  Quadrula aurea (Lea, 1859) -- invalid -- golden orb
  Quadrula couchiana (Lea, 1860) -- valid -- Rio Grande monkeyface
  Quadrula cylindrica (Say, 1817) -- invalid -- rabbitsfoot
  Quadrula cylindrica cylindrica (Say, 1817) -- invalid -- rabbitsfoot
  Quadrula cylindrica strigillata (B. H. Wright, 1898) -- invalid -- rough rabbitsfoot
  Quadrula fragosa (Conrad, 1836) -- valid -- winged mapleleaf, winged mapleleaf mussel
  Quadrula houstonensis (Lea, 1859) -- invalid -- smooth pimpleback
  Quadrula intermedia (Conrad, 1836) -- invalid -- Cumberland monkeyface, Cumberland monkeyface pearly mussel
  Quadrula metanevra (Rafinesque, 1820) -- invalid -- monkeyface
  Quadrula nodulata (Rafinesque, 1820) -- invalid -- wartyback
  Quadrula petrina (Gould, 1855) -- invalid -- Texas pimpleback
  Quadrula pustulosa (Lea, 1831) -- invalid -- pimpleback
  Quadrula pustulosa mortoni (Conrad, 1835) -- invalid -- western pimpleback
  Quadrula pustulosa pustulosa (Lea, 1831) -- invalid -- pimpleback
  Quadrula quadrula (Rafinesque, 1820) -- valid -- mapleleaf
  Quadrula refulgens (Lea, 1868) -- invalid -- purple pimpleback
  Quadrula rumphiana (Lea, 1852) -- invalid -- ridged mapleleaf
  Quadrula sparsa (Lea, 1841) -- invalid -- Appalachian monkeyface, Appalachian monkeyface pearly mussel
  Quadrula stapes (Lea, 1831) -- invalid -- stirrup shell, stirrupshell
  Quadrula tuberosa (Lea, 1840) -- invalid -- rough rockshell
  Quasicorambe Martynov, 1994 -- valid
  Quasicorambe pacifica (MacFarland and O'Donoghue, 1929) -- valid -- frost-spot corambe
  Quincuncina Ortmann in Ortmann & Walker, 1922 -- invalid
  Quincuncina burkei Walker in Ortmann & Walker, 1922 -- invalid -- tapered pigtoe
  Quincuncina infucata (Conrad, 1834) -- invalid -- sculptured pigtoe
  Quincuncina mitchelli (Simpson in Dall, 1896) -- invalid -- false spike
  Quoyula Iredale, 1912 -- valid
  Quoyula kalafuti Petuch, 1987 -- valid
  Rabdotus Albers, 1850 -- valid
  Rabdotus alternatus (Say, 1830) -- valid -- striped rabdotus
  Rabdotus dealbatus (Say, 1821) -- valid -- whitewashed rabdotus
  Rabdotus mooreanus (Pfeiffer, 1868) -- valid -- prairie rabdotus
  Rabdotus pilsbryi (Ferriss, 1925) -- valid -- elongate rabdotus
  Radiocentrum Pilsbry, 1905 -- valid
  Radiocentrum avalonense (Hemphill, 1905) -- valid -- Catalina mountainsnail
  Radiocentrum chiricahuanum (Pilsbry, 1905) -- valid -- chiricahuana mountainsnail, Chiricahua mountainsnail
  Radiocentrum clappi (Ferriss, 1904) -- valid -- Cave Creek mountainsnail
  Radiocentrum ferrissi (Pilsbry, 1915) -- valid -- fringed mountainsnail
  Radiocentrum hachetanum (Pilsbry, 1915) -- valid -- Hacheta mountainsnail
  Radiodiscus Pilsbry and Ferriss, 1906 -- valid
  Radiodiscus abietum H. B. Baker, 1930 -- valid -- fir pinwheel
  Radiodiscus millecostatus Pilsbry and Ferriss, 1906 -- valid -- ribbed pinwheel
  Radix Montfort, 1810 -- valid
  Radix auricularia (Linnaeus, 1758) -- valid -- big-eared radix
  Raeta Gray, 1853 -- valid
  Raeta plicatella (Lamarck, 1818) -- valid -- channeled duckclam
  Raeta undulata (Gould, 1851) -- valid -- Pacific duckclam
  Ranellidae Gray, 1854 -- valid
  Rangia Desmoulins, 1832 -- valid
  Rangia cuneata (G. B. Sowerby I, 1831) -- valid -- Atlantic rangia
  Rangia flexuosa (Conrad, 1840) -- valid -- brown rangia
  Recluzia Petit de la Saussaye, 1853 -- valid
  Recluzia rollandiana Petit de la Saussaye, 1853 -- valid -- brown janthina
  Retifusus Dall, 1916 -- valid
  Retilaskeya Marshall, 1978 -- valid
  Retilaskeya bicolor (C. B. Adams, 1845) -- valid
  Retimohnia caelata (Verrill and Smith, 1880) -- valid
  Retusa T. Brown, 1827 -- valid
  Retusa mayoi (Dall, 1889) -- valid
  Retusa montereyensis A. G. Smith and M. Gordon, 1948 -- valid -- Monterey barrel-bubble
  Retusa obtusa (Montagu, 1803) -- valid -- Arctic barrel-bubble
  Retusa semen (Reeve, 1855) -- valid
  Retusa sulcata (d'Orbigny, 1841) -- valid -- sulcate barrel-bubble
  Retusa umbilicata (Montagu, 1803) -- valid
  Retusa xystrum Dall, 1919 -- valid -- polished barrel-bubble
  Retusidae Thiele, 1925 -- valid
  Rhabdidae Chistikov, 1975 -- valid
  Rhabdus dalli (Pilsbry and Sharp, 1897) -- valid -- dall tuskshell
  Rhabdus rectius (Carpenter, 1865) -- valid -- straight tuskshell
  Rhabdus watsoni (Sharp and Pilsbry, 1897) -- valid -- watson tuskshell
  Rhamphidonta Bernard, 1975 -- valid
  Rhamphidonta retifera (Dall, 1899) -- valid -- netted kellyclam
  Rhapinema F. G. Thompson, 1969 -- valid
  Rhapinema dacryon F. G. Thompson, 1969 -- valid -- Teardrop Snail
  Rhodacme Walker, 1917 -- invalid
  Rhodacme elatior (Anthony, 1855) -- invalid -- domed ancylid
  Rhodacme filosa (Conrad, 1834) -- invalid -- wicker ancylid
  Rhodacme hinkleyi (Walker, 1908) -- invalid -- knobby ancylid
  Rhodopemorpha -- invalid
  Rhodopetala Dall, 1921 -- valid
  Rhodopetala rosea (Dall, 1872) -- valid -- pink limpet
  Rhodopetoma Bartsch, 1944 -- valid
  Rhodopetoma diaulax (Dall, 1908) -- valid
  Rhodopetoma renaudi (Arnold, 1903) -- valid
  Rhodopidae Ihering, 1876 -- valid
  Rhombinella Radwin, 1968 -- valid
  Rhombinella laevigata (Linnaeus, 1758) -- valid -- smooth dovesnail
  Rictaxis Dall, 1871 -- valid
  Rictaxis painei (Dall, 1903) -- valid
  Rictaxis punctocaelatus (Carpenter, 1864) -- valid
  Rictaxis punctostriatus (C. B. Adams, 1840) -- valid -- apitted baby-bubble, pitted baby-bubble
  Rimosodaphnella Schnetler and Beyer, 1990 -- valid
  Rimosodaphnella morra (Dall, 1881) -- valid -- Morra daphnelle
  Rimula DeFrance, 1827 -- valid
  Rimula aequisculpta Dall, 1927 -- valid -- webbed rimula
  Rimula californiana S. S. Berry, 1964 -- valid -- California rimula
  Rimula dorriae Perez Farfante, 1947 -- valid -- coarse rimula
  Rimula frenulata (Dall, 1889) -- valid -- bridle rimula
  Rimula pycnonema Pilsbry, 1943 -- valid -- threaded rimula
  Ringicula Deshayes, 1838 -- valid
  Ringicula nitida A. E. Verrill, 1873 -- valid
  Ringicula semistriata D'Orbigny, 1842 -- valid -- striate helmet-bubble
  Ringiculidae Philippi, 1853 -- valid
  Rissoella J. E. Gray, 1847 -- valid
  Rissoella alaskensis (Bartsch, 1907) -- valid
  Rissoella caribaea Rehder, 1943 -- valid -- Caribbean risso
  Rissoella hertleini A. G. Smith and M. Gordon, 1948 -- valid -- Monterey risso
  Rissoellidae Gray, 1850 -- valid
  Rissoidae Gray, 1847 -- valid
  Rissoina d'Orbigny, 1841 -- valid
  Rissoina californica Bartsch, 1915 -- valid
  Rissoina cancellata Philippi, 1847 -- valid
  Rissoina decussata (Montagu, 1803) -- valid
  Rissoina dyscrita Faber, 1990 -- valid
  Rissoina keenae A. G. Smith and M. Gordon, 1948 -- valid
  Rissoina mayori Dall, 1927 -- valid
  Rissoina multicostata (C. B. Adams, 1850) -- valid
  Rissoina newcombei Dall, 1897 -- valid
  Rissoina sagraiana D'Orbigny, 1842 -- valid
  Rissoina striosa (C. B. Adams, 1850) -- valid
  Rissopsetia Dell, 1956 -- valid
  Rissopsetia hummelincki Faber, 1984 -- valid
  Rochefortia Velain, 1878 -- valid
  Rochefortia compressa Dall, 1913 -- valid -- compressed mysella
  Rochefortia grippi Dall, 1912 -- valid -- elliptical mysella
  Rochefortia tumida (Carpenter, 1864) -- valid -- robust mysella
  Roperia Dall, 1898 -- valid
  Roperia poulsoni (Carpenter, 1864) -- valid
  Rossia pacifica Berry, 1911 -- valid -- eastern pacific bobtail, North Pacific bobtail squid
  Rossia tortugaensis Voss, 1956 -- valid -- Tortugas bobtail squid
  Rostanga Bergh, 1879 -- valid
  Rostanga pulchra MacFarland, 1905 -- valid -- red sponge doris
  Rostangidae Pruvot-Fol, 1951 -- invalid
  Rothelix Miller, 1985 -- valid
  Rothelix cuyamacensis (Pilsbry, 1895) -- valid -- Cuyamaca shoulderband
  Rothelix lowei (Bartsch, 1918) -- valid -- Palomar shoulderband
  Rothelix rhodophila (Reeder and W. B. Miller, 1987) -- valid -- azalea shoulderband
  Rothelix warnerfontis (Reeder and W. B. Miller, 1988) -- valid -- Warner Springs shoulderband
  Rubellatoma Bartsch and Rehder, 1939 -- valid
  Rubellatoma diomedea Bartsch and Rehder, 1939 -- valid
  Rubellatoma rubella (Kurtz and Stimpson, 1851) -- valid -- reddish mangelia
  Rumina Risso, 1826 -- valid
  Rumina decollata (Linnaeus, 1758) -- valid -- decollate snail
  Runcina Forbes and Hanley, 1851 -- valid
  Runcina macfarlandi Gosliner, 1991 -- valid
  Runcinidae H. Adams and A. Adams, 1854 -- valid
  Rupellaria Fleuriau de Bellevue, 1802 -- valid
  Rupellaria cancellata (A. E. Verrill, 1885) -- valid
  Rupellaria cancellatum (A. E. Verrill, 1885) -- invalid -- cancellate rupellaria
  Rupellaria carditoides (Conrad, 1837) -- invalid -- hearty rupellaria
  Rupellaria typica (Jonas, 1844) -- invalid -- Atlantic rupellaria
  Sabia Reeve, 1842 -- valid
  Sabia conica (Schumacher, 1817) -- valid
  Sabinella di Monterosato, 1890 -- valid
  Sabinella troglodytes (Thiele, 1925) -- valid -- pencil-spine eulima
  Saccharoturris Woodring, 1928 -- valid
  Saccharoturris monocingulata (Dall, 1889) -- valid
  Sacoglossa -- invalid
  Sagdidae Pilsbry, 1895 -- valid
  Sakuraeolis Baba, 1965 -- valid
  Sakuraeolis enosimensis (Baba, 1930) -- valid -- white-tentacle Japanese aeolis
  Sanguinolaria Lamarck, 1799 -- valid
  Sanguinolaria sanguinolenta (Gmelin, 1791) -- valid -- Atlantic sanguin
  Sansonia Jousseaume, 1892 -- valid
  Sansonia tuberculata (Watson, 1886) -- valid -- tuberculate cyclostreme
  Sarasinula Grimpe and Hoffmann, 1924 -- valid
  Sarasinula plebeia (P. Fischer, 1868) -- valid -- Caribbean leatherleaf
  Sareptidae Stoliczka, 1870 -- valid
  Saxicavella P. Fischer, 1878 -- valid
  Saxicavella nybakkeni Scott, 1994 -- valid -- truncate saxicave
  Saxicavella pacifica Dall, 1916 -- valid -- little saxicave, elongate saxicave
  Saxidomus Conrad, 1837 -- valid
  Saxidomus gigantea (Deshayes, 1839) -- valid -- Washington butterclam
  Saxidomus giganteus (Deshayes, 1839) -- invalid -- butter clam
  Saxidomus nuttalli Conrad, 1837 -- valid -- California butterclam
  Sayella Dall, 1885 -- valid
  Sayella chesapeakea Morrison, 1939 -- valid
  Sayella fusca (C. B. Adams, 1839) -- valid
  Sayella hemphillii (Dall, 1884) -- valid
  Scabrotrophon McLean, 1996 -- valid
  Scabrotrophon cerritensis (Arnold, 1903) -- valid
  Scabrotrophon clarki J. H. McLean, 1996 -- valid
  Scabrotrophon grovesi J. H. McLean, 1996 -- valid
  Scabrotrophon lasius (Dall, 1919) -- valid -- sandpaper trophon
  Scabrotrophon maltzani (Kobelt and Kuster, 1878) -- valid
  Scabrotrophon scitulus (Dall, 1891) -- valid -- spiny trophon
  Scaeurgus unicirrhus (Chiaie, 1839-41 in Férussac and D'Orbigny, 1834-1848) -- valid -- unicorn octopus, Atlantic warty octopus
  Scaphander Montfort, 1810 -- valid
  Scaphander pilsbryi McGinty, 1955 -- valid
  Scaphander punctostriatus (Mighels and C. B. Adams, 1842) -- valid -- giant canoe-bubble
  Scaphander watsoni Dall, 1881 -- valid
  Scaphander willetti Dall, 1919 -- valid
  Scaphella Swainson, 1832 -- valid
  Scaphella dohrni (G. B. Sowerby III, 1903) -- valid
  Scaphella dubia (Broderip, 1827) -- valid
  Scaphella dubia dubia (Broderip, 1827) -- valid
  Scaphella dubia georgiana (Clench, 1946) -- valid
  Scaphella dubia schmitti (Bartsch, 1931) -- valid
  Scaphella gouldiana (Dall, 1887) -- valid -- banded volute
  Scaphella junonia (Lamarck, 1804) -- valid -- junonia
  Scaphopoda Bronn, 1862 -- valid -- tusk shells, scaphopodes, dentálio, scafópode
  Scelidotoma Choe, Yoon and Habe, 1992 -- valid
  Scelidotoma bella (Gabb, 1865) -- valid -- elegant emarginula
  Schizoplacidae Bergenhayn, 1955 -- invalid
  Schizoplax Dall, 1878 -- valid
  Schizoplax brandtii (Middendorff, 1847) -- valid
  Schwartziella Ponder, 1985 -- valid
  Schwartziella bakeri (Bartsch, 1902) -- valid
  Schwartziella bouryi (Desjardin, 1949) -- valid
  Schwartziella bryerea (Montagu, 1803) -- valid
  Schwartziella catesbyana (d'Orbigny, 1842) -- valid
  Schwartziella cleo (Bartsch, 1915) -- valid
  Schwartziella coronadoensis (Bartsch, 1915) -- valid
  Schwartziella dalli (Bartsch, 1915) -- valid
  Schwartziella fischeri Desjardin, 1949 -- valid
  Schwartziella hannai (A. G. Smith and M. Gordon, 1948) -- valid
  Schwengelia Bartsch, 1947 -- invalid
  Schwengelia hendersoni (Dall, 1927) -- invalid
  Scintillona Finlay, 1926 -- valid
  Scintillona bellerophon O'Foighil and Gibson, 1984 -- valid -- sea-cucumber clam, sea-cucumber galeommatid
  Scissilabra Bartsch, 1907 -- valid
  Scissilabra dalli Bartsch, 1907 -- valid -- splitlip vitrinella
  Scissurella D'Orbigny, 1824 -- valid
  Scissurella cingulata O. G. Costa, 1861 -- valid -- belt scissurelle
  Scissurella proxima Dall, 1927 -- valid -- Florida scissurelle
  Scissurellidae Gray, 1847 -- valid
  Sclerodoris Eliot, 1904 -- valid
  Sclerodoris tanya (Ev. Marcus, 1971) -- valid -- feline doris
  Sconsia Gray, 1847 -- valid
  Sconsia striata (Lamarck, 1816) -- valid -- royal bonnet
  Scutopus Salvini-Plawen, 1968 -- valid
  Scutopus megaradulatus Salvini-Plawen, 1972 -- valid -- corkscrew glistenworm
  Scyllaea Linnaeus, 1758 -- valid
  Scyllaea pelagica Linnaeus, 1758 -- valid -- sargassum nudibranch
  Scyllaeidae Rafinesque, 1815 -- invalid
  Searlesia dira (Reeve, 1846) -- invalid -- dire whelk
  Seguenzia Jeffreys, 1876 -- valid
  Seguenzia giovia Dall, 1919 -- valid -- California seguenzia
  Seguenzia hapala Woodring, 1928 -- valid -- pygmy seguenzia
  Seguenziidae Verrill, 1884 -- valid
  Seila A. Adams, 1861 -- valid
  Seila adamsii (H. C. Lea, 1845) -- valid
  Seila montereyensis Bartsch, 1907 -- valid
  Semele Schumacher, 1817 -- valid
  Semele bellastriata (Conrad, 1837) -- valid -- cancellate semele
  Semele decisa (Conrad, 1837) -- valid -- clipped semele
  Semele proficua (Pulteney, 1799) -- valid -- Atlantic semele
  Semele pulchra (G. B. Sowerby I, 1832) -- valid -- beautiful semele
  Semele purpurascens (Gmelin, 1791) -- valid -- purplish semele
  Semele rubropicta Dall, 1871 -- valid -- rose-painted semele
  Semele rupicola Dall, 1915 -- valid -- rock semele
  Semele venusta (Reeve, 1853) -- valid -- sharp-rib semele
  Semelidae Stoliczka, 1870 -- valid
  Semelina Dall, 1900 -- valid
  Semelina nuculoides (Conrad, 1841) -- valid -- nut semele
  Sepioteuthis sepioidea (Blainville, 1823) -- valid -- Caribbean reef squid
  Septifer Recluz, 1848 -- valid
  Septifer bifurcatus (Conrad, 1837) -- valid -- bifurcate mussel
  Serpulorbis Sasso, 1827 -- valid
  Serpulorbis decussatus (Gmelin, 1791) -- valid -- decussate wormsnail
  Serpulorbis squamiger (Carpenter, 1856) -- valid -- scaled wormsnail
  Serripes Gould, 1841 -- valid
  Serripes groenlandicus (Mohr, 1786) -- valid -- Greenland cockle, Greenland smoothcockle
  Serripes laperousii (Deshayes, 1839) -- valid -- broad cockle, broad smoothcockle
  Serripes notabilis (G. B. Sowerby III, 1915) -- valid -- oblique smoothcockle
  Sigatica Meyer and Aldrich, 1886 -- valid
  Sigatica carolinensis (Dall, 1889) -- valid -- Carolina moonsnail
  Sigatica semisulcata (J. E. Gray, 1839) -- valid -- semisulcate moonsnail
  Siliqua Megerle von Muhlfeld, 1811 -- valid
  Siliqua alta (Broderip and G. B. Sowerby I, 1829) -- valid -- Alaska razor
  Siliqua costata Say, 1822 -- valid -- Atlantic razor
  Siliqua lucida (Conrad, 1837) -- valid -- transparent razor
  Siliqua patula (Dixon, 1789) -- valid -- northern razor, Pacific razor
  Siliqua squama de Blainville, 1824 -- valid -- rough razor
  Siliquariidae Anton, 1838 -- valid
  Similiphora Bouchet, 1985 -- valid
  Similiphora intermedia (C. B. Adams, 1850) -- valid
  Simnialena Cate, 1973 -- valid
  Simnialena marferula Cate, 1973 -- valid -- sea-whip simnia
  Simnialena uniplicata (G. B. Sowerby II, 1848) -- valid -- one-tooth simnia
  Simomactra Dall, 1894 -- valid
  Simomactra falcata (Gould, 1850) -- valid -- hooked surfclam
  Simomactra planulata (Conrad, 1837) -- valid -- flat surfclam
  Simpsonaias Frierson, 1914 -- valid
  Simpsonaias ambigua (Say, 1825) -- valid -- salamander mussel
  Sinezona Finlay, 1927 -- valid
  Sinezona rimuloides (Carpenter, 1865) -- valid -- rim scissurelle
  Sinum Röding, 1798 -- valid
  Sinum debile (Gould, 1853) -- valid -- slight baby ear
  Sinum maculatum (Say, 1831) -- valid -- brown baby ear
  Sinum minus (Dall, 1889) -- valid -- dwarf baby ear
  Sinum perspectivum (Say, 1831) -- valid -- white baby ear
  Sinum scopulosum (Conrad, 1849) -- valid -- fat baby ear
  Siphonaria G. B. Sowerby I, 1823 -- valid
  Siphonaria alternata Say, 1826 -- valid
  Siphonaria brannani Stearns, 1872 -- valid
  Siphonaria pectinata (Linnaeus, 1758) -- valid -- striped false limpet
  Siphonaria thersites Carpenter, 1864 -- valid
  Siphonariidae Gray, 1827 -- valid
  Siphonodentalium quadrifissatum (Pilsbry and Sharp, 1898) -- valid -- four-slit toothshell, fourslit toothshell
  Siraius Marcus, 1955 -- valid
  Siraius bicolor (Bergh, 1884) -- valid
  Siraius kyolis Ev. Marcus and Er. Marcus, 1967 -- valid
  Siratus Jousseaume, 1880 -- invalid
  Siratus beauii (P. Fischer and Bernardi, 1857) -- invalid
  Siratus cailleti (Petit de la Saussaye, 1856) -- invalid
  Siratus consuela (A. H. Verrill, 1950) -- invalid
  Skenea Fleming, 1825 -- valid
  Skenea californica (Bartsch, 1907) -- valid -- California skenea
  Skenea carmelensis A. G. Smith and M. Gordon, 1948 -- valid -- Carmel skenea
  Skenea concordia (Bartsch, 1920) -- valid -- beaded skenea
  Skenea coronadoensis (Arnold, 1903) -- valid -- Coronado skenea
  Skenea diaphana (A. E. Verrill, 1884) -- valid
  Skeneidae W. Clark, 1851 -- valid
  Skeneopsidae Iredale, 1915 -- valid
  Skeneopsis Iredale, 1915 -- valid
  Skeneopsis planorbis (Fabricius, 1780) -- valid -- flat skenea
  Smaragdia Issel, 1869 -- valid
  Smaragdia viridis (Linnaeus, 1758) -- valid -- emerald nerite
  Solamen Iredale, 1924 -- valid
  Solamen columbianum (Dall, 1897) -- valid -- British Columbia crenella
  Solamen leanum (Dall, 1897) -- valid -- Lea crenella
  Solamen megas (Dall, 1902) -- valid -- giant crenella
  Solariella S. V. Wood, 1842 -- valid
  Solariella intermedia (Leche, 1878) -- valid -- intermediate solarelle
  Solariella lacunella (Dall, 1881) -- valid -- channeled solarelle
  Solariella micraulax J. H. McLean, 1964 -- valid -- fine-groove solarelle
  Solariella nuda Dall, 1896 -- valid -- naked solarelle
  Solariella obscura (Couthouy, 1838) -- valid -- obscure solarelle
  Solariella peramabilis Carpenter, 1864 -- valid -- lovely pacific solarelle, lovely solarelle
  Solariella periscopia Dall, 1927 -- valid -- look-around solarelle
  Solariella varicosa (Mighels and C. B. Adams, 1842) -- valid -- varicose solarelle
  Solariorbis Conrad, 1865 -- valid
  Solariorbis arnoldi Bartsch, 1927 -- valid
  Solariorbis blakei (Rehder, 1944) -- valid
  Solariorbis infracarinatus (Gabb, 1881) -- valid
  Solariorbis mooreanus (Vanatta, 1904) -- valid
  Solariorbis terminalis (Pilsbry and McGinty, 1946) -- valid -- terminal vitrinella
  Solatisonax Iredale, 1931 -- valid
  Solatisonax alleryi (Seguenza, 1876) -- valid
  Solatisonax borealis (A. E. Verrill and S. Smith, 1880) -- valid -- boreal sundial
  Solecurtidae d'Orbigny, 1846 -- valid
  Solecurtus de Blainville, 1824 -- valid
  Solecurtus cumingianus Dunker, 1861 -- valid -- corrugate solecurtus
  Solecurtus guaymasensis (Lowe, 1935) -- valid -- Guaymas solecurtus
  Solecurtus sanctaemarthae D'Orbigny, 1842 -- valid -- st. martha solecurrtus, stubby solecurtus
  Solemya borealis Totten, 1834 -- valid -- boreal awningclam
  Solemya grandis A. E. Verrill and Bush, 1898 -- valid -- grand awningclam
  Solemya occidentalis Deshayes, 1857 -- valid -- West Indian awningclam
  Solemya reidi Bernard, 1980 -- valid -- gutless awningclam
  Solemya valvulus (Carpenter, 1864) -- valid -- Pacific awningclam
  Solemya velum Say, 1822 -- valid -- Atlantic awningclam
  Solemyidae Gray, 1840 -- valid
  Solemyoida Dall, 1889 -- invalid
  Solen Linnaeus, 1758 -- valid
  Solen rostriformis Dunker, 1862 -- valid -- rosy jackknife
  Solen sicarius Gould, 1850 -- valid -- sickle jackknife clam, sickle jackknife
  Solen viridis Say, 1821 -- valid -- green jackknife clam, green jackknife
  Solenidae Lamarck, 1809 -- valid
  Somatogyrus Gill, 1863 -- valid
  Somatogyrus alcoviensis Krieger, 1972 -- valid -- Reverse Pebblesnail
  Somatogyrus amnicoloides Walker, 1915 -- valid -- Ouachita pebblesnail
  Somatogyrus aureus Tryon, 1865 -- valid -- Golden Pebblesnail
  Somatogyrus biangulatus Walker, 1906 -- valid -- Angular Pebblesnail
  Somatogyrus constrictus Walker, 1904 -- valid -- Knotty Pebblesnail
  Somatogyrus coosaensis Walker, 1904 -- valid -- Coosa Pebblesnail
  Somatogyrus crassilabris Walker, 1915 -- valid -- Thick-lip Pebblesnail
  Somatogyrus crassus Walker, 1904 -- valid -- Stocky Pebblesnail
  Somatogyrus currierianus (Lea, 1863) -- valid -- Tennessee Pebblesnail
  Somatogyrus decipiens Walker, 1909 -- valid -- Hidden Pebblesnail
  Somatogyrus depressus (Tryon, 1862) -- valid -- Sandbar Pebblesnail
  Somatogyrus excavatus Walker, 1906 -- valid -- Ovate Pebblesnail
  Somatogyrus georgianus Walker, 1904 -- valid -- Cherokee Pebblesnail
  Somatogyrus hendersoni Walker, 1909 -- valid -- Fluted Pebblesnail
  Somatogyrus hinkleyi Walker, 1904 -- valid -- Granite Pebblesnail
  Somatogyrus humerosus Walker, 1906 -- valid -- Atlas Pebblesnail
  Somatogyrus integra (Say, 1829) -- valid -- Ohio Pebblesnail
  Somatogyrus nanus Walker, 1904 -- valid -- Dwarf Pebblesnail
  Somatogyrus obtusus Walker, 1904 -- valid -- Moon Pebblesnail
  Somatogyrus parvulus Tryon, 1865 -- valid -- Sparrow Pebblesnail
  Somatogyrus pennsylvanicus Walker, 1904 -- valid -- Shale Pebblesnail
  Somatogyrus pilsbryanus Walker, 1904 -- valid -- Tallapoosa Pebblesnail
  Somatogyrus pumilus (Conrad, 1834) -- valid -- Compact Pebblesnail
  Somatogyrus pygmaeus Walker, 1909 -- valid -- Pygmy Pebblesnail
  Somatogyrus quadratus Walker, 1906 -- valid -- Quadrate Pebblesnail
  Somatogyrus rheophilas F. G. Thompson, 1984 -- invalid
  Somatogyrus rosewateri M. E. Gordon, 1986 -- valid -- Elk Pebblesnail
  Somatogyrus sargenti Pilsbry, 1895 -- valid -- Mud Pebblesnail
  Somatogyrus strengi Pilsbry and Walker, 1906 -- valid -- Rolling Pebblesnail
  Somatogyrus substriatus Walker, 1906 -- valid -- Choctaw Pebblesnail
  Somatogyrus tenax F. G. Thompson, 1969 -- valid -- Savannah Pebblesnail
  Somatogyrus tennesseensis Walker, 1906 -- valid -- Opaque Pebblesnail
  Somatogyrus trothis Doherty, 1878 -- valid
  Somatogyrus tryoni Pilsbry and F. C. Baker, 1927 -- valid -- Coldwater Pebblesnail
  Somatogyrus virginicus Walker, 1904 -- valid -- Panhandle Pebblesnail
  Somatogyrus walkerianus Aldrich, 1905 -- valid -- Gulf Coast Pebblesnail
  Somatogyrus wheeleri Walker, 1915 -- valid -- Channelled Pebblesnail
  Sonorelix Berry, 1943 -- valid
  Sonorelix avawatzica (S. S. Berry, 1930) -- valid -- Avawatz desertsnail
  Sonorelix baileyi (Bartsch, 1904) -- valid -- Resting Spring desertsnail
  Sonorelix borregoensis (S. S. Berry, 1929) -- valid -- Borrego desertsnail
  Sonorelix harperi (Bryant, 1900) -- valid -- Mountain Spring desertsnail
  Sonorelix melanopylon (S. S. Berry, 1930) -- valid -- Black Rock desertsnail
  Sonorelix rixfordi (Pilsbry, 1919) -- valid -- Joshua Tree desertsnail
  Sonorella Pilsbry, 1900 -- valid
  Sonorella ambigua Pilsbry and Ferriss, 1915 -- valid -- Papago talussnail
  Sonorella anchana S. S. Berry, 1948 -- valid -- Sierra Ancha talussnail, wreathed cactussnail
  Sonorella animasensis Pilsbry, 1939 -- valid -- Animas talussnail, bicolored cactussnail
  Sonorella apache Pilsbry and Ferriss, 1915 -- valid -- Apache talussnail
  Sonorella ashmuni Bartsch, 1904 -- valid -- Richinbar talussnail
  Sonorella baboquivariensis Pilsbry and Ferriss, 1915 -- valid -- Baboquivari talussnail
  Sonorella bagnarai W. B. Miller, 1967 -- valid -- Rincon talussnail
  Sonorella bartschi Pilsbry and Ferriss, 1915 -- valid -- Escabrosa talussnail
  Sonorella bequaerti W. B. Miller, 1967 -- valid -- Happy Valley talussnail
  Sonorella bicipitis Pilsbry and Ferriss, 1910 -- valid -- Dos Cabezas talussnail
  Sonorella binneyi Pilsbry and Ferriss, 1910 -- valid -- Horseshoe Canyon talussnail
  Sonorella bowiensis Pilsbry, 1905 -- valid -- Quartzite Hill talussnail
  Sonorella bradshaveana W. B. Miller, 1984 -- valid -- Bradshaw talussnail
  Sonorella caerulifluminis Pilsbry and Ferriss, 1919 -- valid -- Blue talussnail
  Sonorella christenseni Fairbanks and Reeder, 1980 -- valid -- Clark Peak talussnail
  Sonorella clappi Pilsbry and Ferriss, 1915 -- valid -- Madera talussnail
  Sonorella coloradoensis (Stearns, 1890) -- valid -- Grand Canyon talussnail
  Sonorella coltoniana Pilsbry, 1939 -- valid -- Walnut Canyon talussnail
  Sonorella compar Pilsbry, 1919 -- valid -- Oak Creek talussnail
  Sonorella dalli Bartsch, 1904 -- valid -- Garden Canyon talussnail
  Sonorella danielsi Pilsbry and Ferriss, 1910 -- valid -- Bear Canyon talussnail
  Sonorella delicata Pilsbry and Ferriss, 1919 -- valid -- Tollhouse Canyon talussnail
  Sonorella dragoonensis Pilsbry and Ferriss, 1915 -- valid -- Stronghold Canyon talussnail
  Sonorella eremita Pilsbry and Ferriss, 1915 -- valid -- San Xavier talussnail
  Sonorella ferrissi Pilsbry, 1915 -- valid -- Dragoon talussnail
  Sonorella franciscana Pilsbry and Ferriss, 1919 -- valid -- St. Francis talussnail
  Sonorella galiurensis Pilsbry and Ferriss, 1919 -- valid -- Galiuro talussnail
  Sonorella grahamensis Pilsbry and Ferriss, 1919 -- valid -- Pinaleno talussnail
  Sonorella granulatissima Pilsbry, 1902 -- valid -- Ramsey Canyon talussnail
  Sonorella hachitana (Dall, 1896) -- valid -- New Mexico talussnail
  Sonorella huachucana Pilsbry, 1905 -- valid -- Huachuca talussnail
  Sonorella imitator Gregg and W. B. Miller, 1974 -- valid -- mimic talussnail
  Sonorella imperatrix Pilsbry, 1939 -- valid -- Total Wreck talussnail
  Sonorella imperialis Pilsbry and Ferriss, 1923 -- valid -- Empire Mountain talussnail
  Sonorella insignis Pilsbry and Ferriss, 1919 -- valid -- Whetstone talussnail
  Sonorella macrophallus Fairbanks and Reeder, 1980 -- valid -- Wet Canyon talussnail
  Sonorella magdalenensis (Stearns, 1890) -- valid -- Sonoran talussnail
  Sonorella meadi W. B. Miller, 1966 -- valid -- Agua Dulce talussnail
  Sonorella metcalfi W. B. Miller, 1976 -- valid -- Franklin Mountain talussnail
  Sonorella micra Pilsbry and Ferriss, 1910 -- valid -- pygmy talussnail
  Sonorella micromphala Pilsbry, 1939 -- valid -- mik ranch talussnail, Milk Ranch talussnail
  Sonorella milleri Christensen and Reeder, 1981 -- valid -- Table Top talussnail
  Sonorella mustang Pilsbry and Ferriss, 1919 -- valid -- Mustang talussnail
  Sonorella neglecta Gregg, 1951 -- valid -- Portal talussnail
  Sonorella odorata Pilsbry and Ferriss, 1919 -- valid -- pungent talussnail
  Sonorella optata Pilsbry and Ferris, 1910 -- valid -- Big Emigrant talussnail
  Sonorella orientis Pilsbry, 1936 -- valid -- Organ Mountain talussnail
  Sonorella papagorum Pilsbry and Ferriss, 1915 -- valid -- Black Mountain talussnail
  Sonorella parva Pilsbry, 1905 -- valid -- little talussnail
  Sonorella reederi W. B. Miller, 1984 -- valid -- rampart talussnail
  Sonorella rinconensis Pilsbry and Ferriss, 1910 -- valid -- Posta Quemada talussnail
  Sonorella rosemontensis Pilsbry, 1939 -- valid -- Rosemont talussnail
  Sonorella russelli W. B. Miller, 1984 -- valid -- Black Mesa talussnail
  Sonorella sabinoensis Pilsbry and Ferriss, 1919 -- valid -- Santa Catalina talussnail
  Sonorella santaritana Pilsbry and Ferriss, 1915 -- valid -- aqua caliente talussnail, Agua Caliente talussnail
  Sonorella simmonsi W. B. Miller, 1966 -- valid -- Picacho talussnail
  Sonorella sitiens Pilsbry and Ferriss, 1915 -- valid -- Las Guijas talussnail
  Sonorella superstitionis Pilsbry, 1939 -- valid -- Superstition Mountain talussnail
  Sonorella todseni W. B. Miller, 1976 -- valid -- Dona Ana talussnail
  Sonorella tortillita Pilsbry and Ferriss, 1919 -- valid -- Tortolita talussnail
  Sonorella tryoniana Pilsbry and Ferriss, 1923 -- valid -- Sanford talussnail
  Sonorella vespertina Pilsbry and Ferriss, 1915 -- valid -- evening talussnail
  Sonorella virilis Pilsbry, 1905 -- valid -- Chiricahua talussnail
  Sonorella walkeri Pilsbry and Ferriss, 1915 -- valid -- Santa Rita talussnail
  Sonorella waltoni W. B. Miller, 1968 -- valid -- Doubtful Canyon talussnail
  Sonorella xanthenes Pilsbry and Ferriss, 1923 -- valid -- Kitt Peak talussnail
  Spathochlamys Waller, 1993 -- valid
  Spathochlamys benedicti (A. E. Verrill and Bush, 1897) -- valid -- Benedict scallop, yellow-spot scallop
  Spathochlamys vestalis (Reeve, 1853) -- valid -- blotchy scallop
  Spathoderma Scheltema, 1985 -- valid
  Spathoderma californicum (Schwabl, 1963) -- valid -- jawed solenogaster
  Spathoteredo Moll, 1928 -- valid
  Spathoteredo spatha (Jeffreys, 1860) -- valid -- spathate shipworm
  Speleodiscoides A. G. Smith, 1957 -- valid
  Speleodiscoides spirellum A. G. Smith, 1957 -- valid -- glass coil
  Spengleria Tryon, 1861 -- valid
  Spengleria rostrata (Spengler, 1783) -- valid -- rostrate rocellaria, rostrate gastrochaenid
  Sphaeriidae Deshayes, 1855 -- valid
  Sphaerium Scopoli, 1777 -- valid
  Sphaerium corneum (Linnaeus, 1758) -- valid -- European fingernailclam
  Sphaerium fabale (Prime, 1852) -- valid -- river fingernailclam
  Sphaerium nitidum Westerlund, 1876 -- valid -- Arctic fingernailclam
  Sphaerium occidentale (J. Lewis, 1856) -- valid -- Herrington fingernailclam
  Sphaerium patella (Gould, 1850) -- valid -- Rocky Mountain fingernailclam
  Sphaerium rhomboideum (Say, 1822) -- valid -- rhomboid fingernailclam
  Sphaerium simile (Say, 1817) -- valid -- grooved fingernailclam
  Sphaerium striatinum (Lamarck, 1818) -- valid -- striated fingernailclam
  Sphenia Turton, 1822 -- valid
  Sphenia antillensis Dall and Simpson, 1901 -- valid -- Antillean sphenia
  Sphenia luticola (Valenciennes, 1846) -- valid -- Pacific sphenia
  Sphenia sincera Hanks and Packer, 1985 -- valid -- freeliving sphenia
  Sphenia tumida J. E. Lewis, 1968 -- valid -- tumid sphenia
  Spheniopsidae Gardner, 1928 -- valid
  Spilochlamys F. G. Thompson, 1968 -- valid
  Spilochlamys conica F. G. Thompson, 1968 -- valid -- Conical Siltsnail
  Spilochlamys gravis F. G. Thompson, 1968 -- valid -- Armored Siltsnail
  Spilochlamys turgida F. G. Thompson, 1969 -- valid -- Pumpkin Siltsnail
  Spiraxidae H. B. Baker, 1939 -- valid
  Spirolaxis di Monterosato, 1913 -- valid
  Spirolaxis centrifuga (di Monterosato, 1890) -- valid -- exquisite false dial, exquisite false-dial
  Spirolaxis lamellifer (Rehder, 1935) -- valid -- lamellate false-dial
  Spiromoelleria Baxter and J. H. McLean, 1984 -- valid
  Spiromoelleria kachemakensis Baxter and J. H. McLean, 1984 -- valid
  Spiromoelleria quadrae (Dall, 1897) -- valid
  Spisula Gray, 1837 -- valid
  Spisula catilliformis Conrad, 1867 -- invalid -- dish surfclam
  Spisula falcata (Gould, 1850) -- invalid -- hooked surfclam
  Spisula hemphillii (Dall, 1894) -- invalid -- Hemphill surfclam
  Spisula planulata (Conrad, 1837) -- invalid -- flat surfclam
  Spisula raveneli (Conrad, 1831) -- valid -- southern surfclam
  Spisula solidissima (Dillwyn, 1817) -- valid -- Atlantic surfclam
  Splendrillia Hedley, 1922 -- valid
  Splendrillia fucata (Reeve, 1845) -- valid
  Splendrillia halidorema (Schwengel, 1940) -- valid
  Splendrillia janetae Bartsch, 1934 -- valid
  Splendrillia kathyae (Tippett, 1995) -- valid
  Splendrillia lissotropis (Dall, 1881) -- valid
  Splendrillia moseri (Dall, 1889) -- valid
  Splendrillia moseri brunnescens Rehder, 1943 -- valid
  Splendrillia moseri moseri (Dall, 1889) -- valid
  Splendrillia pagodula (Dall, 1889) -- valid
  Splendrillia petiti (Tippett, 1995) -- valid
  Splendrillia sunderlandi Petuch, 1987 -- valid
  Splendrillia woodringi (Bartsch, 1934) -- valid
  Spondylidae Gray, 1826 -- valid
  Spondylus Linnaeus, 1758 -- valid
  Spondylus americanus Hermann, 1781 -- valid -- Atlantic thorny oyster
  Spondylus ictericus Reeve, 1856 -- valid -- digitate thorny oyster
  Sportellidae Dall, 1899 -- valid
  Spurilla Bergh, 1864 -- valid
  Spurilla neapolitana (delle Chiaje, 1823) -- valid -- neapolitan spurilla
  Spurilla verrucicornis (A. Costa, 1867) -- valid
  Spurwinkia Davis, Mazurkiewicz and Mandracchia, 1982 -- valid
  Spurwinkia salsa (Pilsbry, 1905) -- valid -- Saltmarsh Hydrobe
  Stagnicola Leach, 1830 -- valid
  Stagnicola apicina (Lea, 1838) -- valid -- Abbreviate Pondsnail
  Stagnicola arctica (Lea, 1864) -- valid -- Arctic Pondsnail
  Stagnicola bonnevillensis (Call, 1884) -- valid -- Fat-Whorled Pondsnail
  Stagnicola caperata (Say, 1829) -- valid -- Wrinkled Marshsnail
  Stagnicola catescopium (Say, 1817) -- invalid -- woodland pondsnail
  Stagnicola contracta (Currier, 1881) -- valid -- Deepwater Pondsnail
  Stagnicola elodes (Say, 1821) -- valid -- Marsh Pondsnail
  Stagnicola elrodi (F. C. Baker and J. Henderson, 1933) -- valid -- Flathead Pondsnail
  Stagnicola elrodiana F. C. Baker, 1935 -- valid -- Longmouth Pondsnail
  Stagnicola emarginata (Say, 1821) -- valid -- St. Lawrence Pondsnail
  Stagnicola exilis (Lea, 1834) -- valid -- Flat-Whorled Pondsnail
  Stagnicola gabbi (Tryon, 1865) -- valid -- Striate Pondsnail
  Stagnicola hinkleyi (F. C. Baker, 1906) -- valid -- Rustic Pondsnail
  Stagnicola idahoensis (J. Henderson, 1931) -- valid -- Shortspire Pondsnail
  Stagnicola mighelsi (W. G. Binney, 1865) -- valid -- Bigmouth Pondsnail
  Stagnicola montanensis (F. C. Baker, 1913) -- valid -- Mountain Marshsnail
  Stagnicola neopalustris (F. C. Baker, 1911) -- valid -- Piedmont Pondsnail
  Stagnicola oronoensis (F. C. Baker, 1904) -- valid -- Obese Pondsnail
  Stagnicola petoskeyensis (Walker, 1908) -- valid -- Petoskey Pondsnail
  Stagnicola pilsbryi (Hemphill, 1890) -- valid -- Fish Springs Marshsnail
  Stagnicola traski (Tryon, 1863) -- valid -- Widelip Pondsnail
  Stagnicola utahensis (Call, 1884) -- valid -- Thickshell Pondsnail
  Stagnicola walkeriana F. C. Baker, 1926 -- valid -- Calabash Pondsnail
  Stagnicola woodruffi (F. C. Baker, 1901) -- valid -- Coldwater Pondsnail
  Steironepion Pilsbry and Lowe, 1932 -- valid
  Steironepion minor (C. B. Adams, 1845) -- valid -- banded dovesnail
  Steironepion moniliferum (G. B. Sowerby I, 1844) -- valid -- many-spotted dovesnail
  Stellatoma Bartsch and Rehder, 1939 -- valid
  Stellatoma stellata (Stearns, 1872) -- valid
  Stenophysa von Martens, 1898 -- valid
  Stenophysa marmorata (Guilding, 1828) -- valid -- marbled aplexa
  Stenophysa maugeriae (J. E. Gray, 1837) -- valid -- tawny aplexa
  Stenoplax Dall, 1879 -- valid
  Stenoplax bahamensis Kaas and Van Belle, 1987 -- valid
  Stenoplax boogii (Haddon, 1886) -- valid
  Stenoplax conspicua (Pilsbry, 1892) -- valid
  Stenoplax corrugata (Pilsbry, 1892) -- valid
  Stenoplax fallax (Pilsbry, 1892) -- valid
  Stenoplax floridana (Pilsbry, 1892) -- valid
  Stenoplax heathiana S. S. Berry, 1946 -- valid
  Stenoplax producta (Reeve, 1847) -- invalid
  Stenoplax purpurascens (C. B. Adams, 1845) -- valid
  Stenosemus von Middendorff, 1847 -- valid
  Stenosemus albus (Linnaeus, 1767) -- invalid -- northern white chiton
  Stenosemus exaratus (G. O. Sars, 1878) -- invalid
  Stenotrema Rafinesque, 1819 -- valid
  Stenotrema altispira (Pilsbry, 1894) -- valid -- highland slitmouth
  Stenotrema angellum Hubricht, 1958 -- valid -- Kentucky slitmouth
  Stenotrema barbatum (G. H. Clapp, 1904) -- valid -- bristled slitmouth
  Stenotrema barbigerum (Redfield, 1856) -- valid -- fringed slitmouth
  Stenotrema blandianum (Pilsbry, 1903) -- valid -- Missouri slitmouth
  Stenotrema brevipila (G. H. Clapp, 1907) -- valid -- Talladega slitmouth
  Stenotrema burringtoni Grimm, 1971 -- valid
  Stenotrema calvescens Hubricht, 1961 -- valid -- Chattanooga slitmouth
  Stenotrema cohuttense (G. H. Clapp, 1914) -- valid -- Cohutta slitmouth
  Stenotrema deceptum (G. H. Clapp, 1905) -- valid -- Monte Sano slitmouth
  Stenotrema depilatum (Pilsbry, 1895) -- valid -- Great Smoky slitmouth
  Stenotrema edgarianum (I. Lea, 1841) -- valid -- Sequatchie slitmouth
  Stenotrema edvardsi (Bland, 1856) -- valid -- ridge-and-valley slitmouth
  Stenotrema exodon (Pilsbry, 1900) -- valid -- Alabama slitmouth
  Stenotrema florida Pilsbry, 1940 -- valid -- Apalachicola slitmouth
  Stenotrema hirsutum (Say, 1817) -- valid -- hairy slitmouth
  Stenotrema labrosum (Bland, 1862) -- valid -- Ozark slitmouth
  Stenotrema magnifumosum (Pilsbry, 1900) -- valid -- Appalachian slitmouth
  Stenotrema maxillatum (Gould, 1848) -- valid -- ridge-lip slitmouth
  Stenotrema pilsbryi (Ferriss, 1900) -- valid -- Rich Mountain slitmouth
  Stenotrema pilula (Pilsbry, 1900) -- valid -- pygmy slitmouth
  Stenotrema simile Grimm, 1971 -- valid -- Bear Creek slitmouth
  Stenotrema spinosum (I. Lea, 1830) -- valid -- carinate slitmouth
  Stenotrema stenotrema (Pfeiffer, 1842) -- valid -- inland slitmouth
  Stenotrema unciferum (Pilsbry, 1900) -- valid -- oachita slitmouth, Ouachita slitmouth
  Stenotrema waldense Archer, 1938 -- valid -- Doaks Creek slitmouth
  Sterkia Pilsbry, 1898 -- valid
  Sterkia clementina (Sterki, 1890) -- valid -- insular birddrop
  Sterkia eryiesi (Drouet, 1859) -- invalid
  Sterkia eryiesi rhoadsi (Pilsbry, 1899) -- invalid -- Caribbean birddrop
  Sterkia eyriesii (Drouet, 1859) -- valid -- Caribbean birddrop
  Sterkia eyriesii eyriesii (Drouet, 1859) -- valid
  Sterkia eyriesii rhoadsi (Pilsbry, 1899) -- valid -- Caribbean birddrop
  Sterkia hemphilli (Sterki, 1890) -- valid -- California birddrop
  Sthenorytis Conrad, 1862 -- valid
  Sthenorytis pernobilis (P. Fischer and Bernardi, 1857) -- valid -- noble wentletrap
  Stigmaulax Mörch, 1852 -- valid
  Stigmaulax sulcatus (Born, 1778) -- valid -- grooved moonsnail
  Stiliger Ehrenberg, 1828 -- valid
  Stiliger fuscovittatus Lance, 1962 -- valid -- brown-streak stiliger
  Stiliger vossi Ev. Marcus and Er. Marcus, 1960 -- valid
  Stiligeridae Iredale and O'Donoghue, 1923 -- invalid
  Stiobia F. G. Thompson and McCaleb, 1978 -- valid
  Stiobia nana F. G. Thompson, 1978 -- valid -- Sculpin Snail
  Stosicia Brusina, 1871 -- valid
  Stosicia aberrans (C. B. Adams, 1850) -- valid
  Stramonita Schumacher, 1817 -- valid
  Stramonita haemastoma (Linnaeus, 1758) -- valid -- Florida rocksnail
  Stramonita haemastoma canaliculata (J. E. Gray, 1839) -- valid -- Florida rocksnail
  Stramonita haemastoma floridana (Conrad, 1837) -- valid -- Florida rocksnail
  Stramonita haemastoma haemastoma (Linnaeus, 1758) -- valid
  Stramonita rustica (Lamarck, 1822) -- valid -- rustic rocksnail
  Streptaxidae Gray, 1860 -- valid
  Striatura E. S. Morse, 1864 -- valid
  Striatura exigua (Stimpson, 1850) -- valid -- ribbed striate
  Striatura ferrea E. S. Morse, 1864 -- valid -- black striate
  Striatura meridionalis (Pilsbry and Ferriss, 1906) -- valid -- median striate
  Striatura milium (E. S. Morse, 1859) -- valid -- fine-ribbed striate
  Striatura pugetensis (Dall, 1895) -- valid -- northwest striate
  Strictispira McLean, 1971 -- valid
  Strictispira solida (C. B. Adams, 1850) -- valid -- solid drillia
  Strictispiridae McLean, 1971 -- valid
  Strigilla Turton, 1822 -- valid
  Strigilla carnaria (Linnaeus, 1758) -- valid -- large strigilla
  Strigilla gabbi Olsson and McGinty, 1958 -- valid -- gabb strigilla, rayed strigilla
  Strigilla mirabilis (Philippi, 1841) -- valid -- white strigilla
  Strigilla pisiformis (Linnaeus, 1758) -- valid -- pea strigilla
  Strigilla surinamensis Boss, 1972 -- valid -- Surinam strigilla
  Strobilops Pilsbry, 1893 -- valid
  Strobilops aeneus Pilsbry, 1926 -- valid -- bronze pinecone
  Strobilops affinis Pilsbry, 1893 -- valid -- eightfold pinecone
  Strobilops hubbardi (A. D. Brown, 1861) -- valid -- flattened pinecone
  Strobilops texasianus Pilsbry and Ferriss, 1906 -- valid -- southern pinecone
  Strobilopsidae Wenz, 1915 -- valid
  Strombidae Rafinesque, 1815 -- valid
  Strombus Linnaeus, 1758 -- valid
  Strombus alatus Gmelin, 1791 -- valid -- Florida fighting conch
  Strombus costatus Gmelin, 1791 -- valid -- milk conch
  Strombus gallus Linnaeus, 1758 -- valid -- roostertail conch
  Strombus gigas Linnaeus, 1758 -- valid -- pink or queen conch, queen conch
  Strombus pugilis Linnaeus, 1758 -- valid -- West Indian fighting conch
  Strombus raninus Gmelin, 1791 -- valid -- hawkwing conch
  Strophitus Rafinesque, 1820 -- valid
  Strophitus connasaugaensis (Lea, 1858) -- invalid -- Alabama creekmussel
  Strophitus subvexus (Conrad, 1834) -- invalid -- southern creekmussel
  Strophitus undulatus (Say, 1817) -- valid -- creeper
  Stygopyrgus Hershler and Longley, 1986 -- valid
  Stygopyrgus bartonensis Hershler and Longley, 1986 -- valid -- Barton Cavesnail
  Stylidium Dall, 1907 -- valid
  Stylidium eschrichtii (Middendorff, 1849) -- valid -- threaded cerith
  Styliola Gray, 1850 -- valid
  Styliola subula (Quoy and Gaimard, 1827) -- valid -- keeled clio
  Stylocheilus Gould, 1852 -- valid
  Stylocheilus citrinus (Rang, 1828) -- valid -- yellow seahare, yellow seacat
  Stylocheilus longicauda (Quoy and Gaimard, 1825) -- valid -- blue-ring seahare, longtail seacat
  Stylommatophora -- invalid
  Suavodrillia Dall, 1918 -- valid
  Suavodrillia kennicotti (Dall, 1871) -- valid
  Suavodrillia willetti Dall, 1919 -- valid
  Subulina Beck, 1837 -- valid
  Subulina octona (Bruguiere, 1792) -- valid -- miniature awlsnail
  Subulinidae P. Fischer and Crosse, 1877 -- invalid
  Succinea Draparnaud, 1801 -- valid
  Succinea barberi (W. B. Marshall, 1926) -- valid -- Sanibel ambersnail
  Succinea californica P. Fischer and Crosse, 1878 -- valid -- San Tomas ambersnail
  Succinea campestris Say, 1817 -- valid -- crinkled ambersnail
  Succinea floridana Pilsbry, 1905 -- valid -- Florida chalksnail
  Succinea forsheyi I. Lea, 1864 -- valid -- spotted ambersnail
  Succinea greerii Tryon, 1866 -- valid -- dryland ambersnail
  Succinea grosvenori I. Lea, 1864 -- valid -- Santa Rita ambersnail
  Succinea indiana Pilsbry, 1905 -- valid -- xeric ambersnail
  Succinea luteola Gould, 1848 -- valid -- Mexico ambersnail
  Succinea oregonensis I. Lea, 1841 -- valid -- Oregon ambersnail
  Succinea paralia Hubricht, 1983 -- valid -- saltmarsh ambersnail
  Succinea pennsylvanica Pilsbry, 1948 -- valid -- Penn ambersnail
  Succinea pseudavara Webb, 1954 -- valid
  Succinea putris (Linnaeus, 1758) -- valid -- European ambersnail
  Succinea rusticana Gould, 1846 -- valid -- rustic ambersnail
  Succinea solastra Hubricht, 1961 -- valid -- Lone Star ambersnail
  Succinea strigata Pfeiffer, 1855 -- valid -- striate ambersnail
  Succinea unicolor Tryon, 1866 -- valid -- squatty ambersnail
  Succinea urbana Hubricht, 1961 -- valid -- urban ambersnail
  Succinea vaginacontorta C. B. Lee, 1951 -- valid
  Succinea wilsonii I. Lea, 1864 -- valid -- golden ambersnail
  Succineidae Beck, 1837 -- valid
  Suhinia Martynov, 1994 -- valid
  Suhinia steinbergae (Lance, 1962) -- valid
  Supplanaxis Thiele, 1929 -- valid
  Supplanaxis nucleus (Bruguiere, 1789) -- valid -- black planaxis
  Suturoglypta Radwin, 1968 -- valid
  Suturoglypta iontha (Ravenel, 1861) -- valid -- lineate dovesnail
  Suturoglypta pretrii (Duclos, 1846) -- valid
  Synaptocochlea Pilsbry, 1890 -- valid
  Synaptocochlea picta (d'Orbigny, 1842) -- valid -- painted false stomatella
  Syncyclonemidae -- invalid
  Systellommatophora -- invalid
  Tachyrhynchus Morch, 1868 -- valid
  Tachyrhynchus erosus (Couthouy, 1838) -- valid -- eroded turretsnail
  Tachyrhynchus lacteolus (Carpenter, 1864) -- valid -- milky turretsnail
  Tachyrhynchus pratomus Dall, 1919 -- valid
  Tachyrhynchus reticulatus (Mighels and C. B. Adams, 1842) -- valid
  Tachyrhynchus stearnsii Dall, 1919 -- valid
  Tagelus Gray, 1847 -- valid
  Tagelus affinis (C. B. Adams, 1852) -- valid -- neighbor tagelus
  Tagelus californianus (Conrad, 1837) -- valid -- California tagelus
  Tagelus divisus (Spengler, 1794) -- valid -- purplish tagelus
  Tagelus plebeius (Lightfoot, 1786) -- valid -- stout tagelus
  Tagelus subteres (Conrad, 1837) -- valid -- lesser tagelus
  Talparia Troschel, 1863 -- valid
  Talparia cinerea (Gmelin, 1791) -- valid -- Atlantic gray cowrie
  Tambja Burn, 1962 -- valid
  Tambja gratiosa (Bergh, 1890) -- valid
  Tapes philippinarum (A. Adams and Reeve, 1850) -- invalid -- Japanese littleneck
  Taranis Jeffreys, 1870 -- valid
  Taranis morchii (Malm, 1861) -- valid
  Tarebia H. Adams and A. Adams, 1854 -- valid
  Tarebia granifera (Lamarck, 1822) -- valid -- quilted melania
  Taringa Er. Marcus, 1955 -- valid
  Taringa aivica Ev. Marcus and Er. Marcus, 1967 -- valid -- dusky brown taringa
  Taringa aivica timia Ev. Marcus and Er. Marcus, 1967 -- valid -- dusky brown taringa
  Taringa telopia Er. Marcus, 1955 -- valid
  Taylorconcha Hershler, Frest, Johannes, Bowler and F. G. Thompson, 1994 -- valid
  Taylorconcha serpenticola Hershler, Frest, Johannes, Bowler and F. G. Thompson, 1994 -- valid -- Bliss Rapids Snail
  Tectarius Valenciennes, 1833 -- valid
  Tectarius antonii (Philippi, 1846) -- valid -- false pricklywinkle
  Tectonatica Sacco, 1890 -- valid
  Tectonatica pusilla (Say, 1822) -- valid -- miniature moonsnail
  Tectura Gray, 1847 -- valid
  Tectura depicta (Hinds, 1842) -- valid -- painted limpet
  Tectura fenestrata (Reeve, 1855) -- valid -- fenestrate limpet
  Tectura paleacea (Gould, 1853) -- valid -- surfgrass limpet
  Tectura persona (Rathke, 1833) -- valid -- mask limpet
  Tectura rosacea (Carpenter, 1864) -- valid -- Pacific rosy limpet
  Tectura scutum (Rathke, 1833) -- valid -- plate limpet
  Tectura testudinalis (Muller, 1776) -- valid -- plant limpet
  Tegula Lesson, 1835 -- valid
  Tegula aureotincta (Forbes, 1850) -- valid -- gilded tegula
  Tegula brunnea Philippi, 1848 -- valid -- brown tegula
  Tegula eiseni Jordan, 1936 -- valid -- western banded tegula, banded tegula
  Tegula excavata (Lamarck, 1822) -- valid -- green-base tegula
  Tegula fasciata (Born, 1778) -- valid -- silky tegula
  Tegula funebralis (A. Adams, 1855) -- valid -- black tegula
  Tegula gallina (Forbes, 1850) -- valid -- speckled tegula
  Tegula gruneri (Philippi, 1849) -- valid -- gem tegula
  Tegula hotessieriana (d'Orbigny, 1842) -- valid -- Caribbean tegula
  Tegula lividomaculata (C. B. Adams, 1845) -- valid -- West Indian tegula
  Tegula montereyi (Kiener, 1850) -- valid -- Monterey tegula
  Tegula pulligo (Gmelin, 1791) -- valid -- dusky tegula
  Tegula regina Stearns, 1892 -- valid -- queen tegula
  Teinostoma H. Adams and A. Adams, 1853 -- valid
  Teinostoma biscaynense Pilsbry and McGinty, 1945 -- valid -- Biscayne vitrinella
  Teinostoma carinicallus Pilsbry and McGinty, 1946 -- valid
  Teinostoma clavium Pilsbry and McGinty, 1945 -- valid
  Teinostoma cocolitoris Pilsbry and McGinty, 1945 -- valid
  Teinostoma cryptospira (A. E. Verrill, 1884) -- valid
  Teinostoma goniogyrus Pilsbry and McGinty, 1945 -- valid
  Teinostoma incertum Pilsbry and McGinty, 1945 -- valid
  Teinostoma lerema Pilsbry and McGinty, 1945 -- valid
  Teinostoma lituspalmarum Pilsbry and McGinty, 1945 -- valid
  Teinostoma megastoma (C. B. Adams, 1850) -- valid
  Teinostoma minusculum (Bush, 1897) -- valid
  Teinostoma parvicallum Pilsbry and McGinty, 1945 -- valid
  Teinostoma reclusum (Dall, 1889) -- valid
  Teinostoma sapiella Dall, 1919 -- valid
  Teinostoma semistriatum (d'Orbigny, 1842) -- valid
  Teinostoma supravallatum (Carpenter, 1864) -- valid -- upright vitrinella
  Tellidora Morch, 1856 -- valid
  Tellidora cristata (Recluz, 1842) -- valid -- white-crest tellin
  Tellina Linnaeus, 1758 -- valid
  Tellina aequistriata Say, 1824 -- valid -- striate tellin
  Tellina agilis Stimpson, 1857 -- valid -- northern dwarf tellin, northern dwarf-tellin
  Tellina alternata Say, 1822 -- valid -- alternate tellin
  Tellina americana Dall, 1900 -- valid -- American tellin
  Tellina angulosa Gmelin, 1791 -- valid -- angulate tellin
  Tellina bodegensis Hinds, 1845 -- valid -- Bodega tellin
  Tellina candeana D'Orbigny, 1842 -- valid -- cande tellin, wedge tellin
  Tellina carpenteri Dall, 1900 -- valid -- Carpenter tellin
  Tellina colorata Dall, 1900 -- valid -- tinted tellin
  Tellina consobrina D'Orbigny, 1842 -- valid -- consobrine tellin
  Tellina cristallina Spengler, 1798 -- valid -- crystal tellin
  Tellina fausta Pulteney, 1799 -- valid -- favored tellin
  Tellina gouldii Hanley, 1846 -- valid -- cuneate tellin
  Tellina idae Dall, 1891 -- valid -- Ida tellin
  Tellina iris Say, 1822 -- valid -- rainbow tellin
  Tellina laevigata Linnaeus, 1758 -- valid -- smooth tellin
  Tellina lineata Turton, 1819 -- valid -- rose-petal tellin
  Tellina listeri Roding, 1798 -- valid -- speckled tellin
  Tellina lutea W. Wood, 1828 -- valid -- alaska great tellin, Alaska great-tellin
  Tellina magna Spengler, 1798 -- valid -- great tellin
  Tellina martinicensis D'Orbigny, 1842 -- valid -- Martinique tellin
  Tellina mera Say, 1834 -- valid -- pure tellin
  Tellina meropsis Dall, 1900 -- valid -- oval tellin
  Tellina modesta (Carpenter, 1864) -- valid -- plain tellin
  Tellina nitens C. B. Adams, 1845 -- valid -- shiny dwarf tellin, shiny dwarf-tellin
  Tellina nuculoides (Reeve, 1854) -- valid -- salmon tellin
  Tellina paramera Boss, 1964 -- valid -- perfect tellin
  Tellina persica Dall and Simpson, 1901 -- valid -- apricot tellin
  Tellina probina Boss, 1964 -- valid -- slandered tellin
  Tellina radiata Linnaeus, 1758 -- valid -- sunrise tellin
  Tellina similis J. Sowerby, 1806 -- valid -- candystick tellin
  Tellina squamifera Deshayes, 1855 -- valid -- crenulate tellin
  Tellina sybaritica Dall, 1881 -- valid -- sybaritic tellin
  Tellina tampaensis Conrad, 1866 -- valid -- Tampa tellin
  Tellina tenella A. E. Verrill, 1874 -- valid -- delicate tellin
  Tellina texana Dall, 1900 -- valid -- say tellin, Texas tellin
  Tellina versicolor DeKay, 1843 -- valid -- many-colored tellin
  Tellina vespuciana (d'Orbigny, 1842) -- valid -- Vespucci tellin
  Tellinidae Blainville, 1814 -- valid
  Tenagodus Guettard, 1770 -- valid
  Tenagodus squamatus (de Blainville, 1827) -- valid -- slit wormsnail
  Tenaturris Woodring, 1928 -- valid
  Tenaturris bartletti (Dall, 1889) -- valid
  Tenaturris janira (Dall, 1919) -- valid
  Tenellia A. Costa, 1866 -- valid
  Tenellia adspersa (Nordmann, 1845) -- valid -- miniature aeolis
  Tenellia fuscata (Gould, 1870) -- valid
  Teralatirus Coomans, 1965 -- valid
  Teralatirus cayohuesonicus (G. B. Sowerby III, 1878) -- valid -- Key West latirus
  Terebra Bruguiere, 1789 -- valid
  Terebra acrior Dall, 1889 -- valid
  Terebra alba J. E. Gray, 1834 -- valid
  Terebra arcas Abbott, 1954 -- valid -- Arcas auger
  Terebra armillata Hinds, 1844 -- valid
  Terebra concava (Say, 1826) -- valid -- concave auger
  Terebra crenifera Deshayes, 1859 -- valid -- western crenate auger
  Terebra danai S. S. Berry, 1958 -- invalid
  Terebra dislocata (Say, 1822) -- valid -- eastern auger
  Terebra doellojuradoi Carcelles, 1953 -- valid
  Terebra floridana Dall, 1889 -- valid -- yellow auger
  Terebra glossema Schwengel, 1942 -- valid -- tongue auger
  Terebra hemphilli Vanatta, 1924 -- valid
  Terebra lindae Petuch, 1987 -- valid
  Terebra nassula Dall, 1889 -- valid -- woven auger
  Terebra onslowensis Petuch, 1972 -- invalid -- onslow auger
  Terebra pedroana Dall, 1908 -- valid -- San Pedro auger
  Terebra protexta (Conrad, 1846) -- valid -- fine-ribbed auger
  Terebra rushii Dall, 1889 -- valid -- porcelain auger
  Terebra taurina (Lightfoot, 1786) -- valid -- flame auger
  Terebra texana Dall, 1898 -- invalid -- Texas auger
  Terebra vinosa Dall, 1889 -- valid -- lilac auger
  Terebridae H. and A. Adams, 1854 -- invalid
  Teredinidae Rafinesque, 1815 -- valid
  Teredo Linnaeus, 1758 -- valid
  Teredo bartschi W. Clapp, 1923 -- valid -- Bartsch shipworm
  Teredo fulleri W. Clapp, 1924 -- valid -- yellow-margin shipworm
  Teredo furcifera von Martens, 1894 -- valid -- deep-cleft shipworm
  Teredo navalis Linnaeus, 1758 -- valid -- naval shipworm
  Teredo portoricensis W. Clapp, 1924 -- valid -- Puerto Rico shipworm
  Teredora Bartsch, 1921 -- valid
  Teredora malleolus (Turton, 1822) -- valid -- malleate shipworm
  Tergipedidae Bergh, 1889 -- valid
  Tergipes Cuvier, 1805 -- valid
  Tergipes tergipes (Forskal, 1775) -- valid
  Teskeyostrea Harry, 1985 -- valid
  Teskeyostrea weberi (Olsson, 1951) -- valid -- weber oyster, threaded oyster
  Testacella Cuvier, 1801 -- valid
  Testacella haliotidea Draparnaud, 1801 -- valid -- earshell slug
  Testacellidae Gray, 1840 -- valid
  Tethyidae Rafinesque, 1815 -- invalid
  Texadina Abbott and Ladd, 1951 -- valid
  Texadina barretti (Morrison, 1965) -- valid -- Boone Hydrobe
  Texadina sphinctostoma (Abbott and Ladd, 1951) -- valid -- Narrowmouth Hydrobe
  Texapyrgus F. G. Thompson and Hershler, 1991 -- valid
  Texapyrgus longleyi F. G. Thompson and Hershler, 1991 -- valid -- Striated Hydrobe
  Thais Roding, 1798 -- valid
  Thais deltoidea (Lamarck, 1822) -- valid -- deltoid rocksnail
  Thais haemastoma (Linnaeus, 1758) -- invalid
  Thais haemastoma canaliculata (J. E. Gray, 1839) -- invalid
  Thais haemastoma floridana (Conrad, 1837) -- invalid -- Florida rocksnail
  Thais haemastoma haemastoma (Linnaeus, 1758) -- invalid
  Thais haemastoma haysae Clench, 1927 -- invalid
  Thais rustica (Lamarck, 1822) -- invalid -- rustic rocksnail
  Thala H. Adams and A. Adams, 1853 -- valid
  Thala floridana (Dall, 1884) -- valid
  Thala foveata (Sowerby, 1874) -- valid -- beaded thala
  Thala gratiosa (Reeve, 1845) -- valid -- esteemed miter
  Thaleia Waren, 1979 -- valid
  Thaleia nisonis (Dall, 1889) -- valid -- regal benthonella
  Theba Risso, 1826 -- valid
  Theba pisana (Muller, 1774) -- valid -- white gardensnail
  Thecacera Fleming, 1828 -- valid
  Thecacera pennigera (Montagu, 1815) -- valid
  Thecosomata Blainville, 1824 -- invalid
  Thelecythara Woodring, 1928 -- valid
  Thelecythara floridana Fargo, 1953 -- valid
  Thelecythara mucronata (Guppy, 1896) -- valid
  Theora H. Adams and A. Adams, 1856 -- valid
  Theora lubrica Gould, 1861 -- valid -- Asian semele
  Thesbia Jeffreys, 1867 -- valid
  Thesbia nana (Loven, 1846) -- valid
  Thiaridae Gill, 1871 -- valid
  Thliptodon diaphanus (Meisenheimer, 1903) -- valid
  Thliptodontidae Kwietniewski, 1902 -- invalid
  Thordisa Bergh, 1877 -- valid
  Thordisa bimaculata Lance, 1966 -- valid -- two-spot thordis
  Thordisa rubescens Behrens and R. Henderson, 1981 -- valid -- red thordis
  Thracia Leach in Blainville, 1824 -- valid
  Thracia challisiana Dall, 1915 -- valid -- Challis thracia, pustulose thracia
  Thracia condoni Dall, 1909 -- valid -- smooth thracia
  Thracia conradi Couthouy, 1839 -- valid -- Conrad thracia, undulate thracia
  Thracia curta Conrad, 1837 -- valid -- short thracia
  Thracia devexa G. O. Sars, 1878 -- valid -- sloping thracia
  Thracia morrisoni R. E. Petit, 1964 -- valid -- Morrison thracia, wrinkled thracia
  Thracia myopsis Møller, 1842 -- valid -- Arctic thracia
  Thracia phaseolina (Lamarck, 1822) -- valid -- kidneybean thracia
  Thracia septentrionalis Jeffreys, 1872 -- valid -- northern thracia
  Thracia stimpsoni Dall, 1886 -- valid -- Stimpson thracia
  Thracia trapezoides Conrad, 1849 -- valid -- trapezoid thracia
  Thraciidae Stoliczka, 1870 -- valid
  Thuridilla Bergh, 1872 -- valid
  Thuridilla picta (A. E. Verrill, 1901) -- valid -- painted elysia
  Thyasira Lamarck, 1818 -- valid
  Thyasira equalis (A. E. Verrill and Bush, 1898) -- valid -- equal cleftclam
  Thyasira ferruginea Winckworth, 1932 -- invalid -- reddish cleftclam
  Thyasira flexuosa (Montagu, 1803) -- valid -- flexuose cleftclam
  Thyasira granulosa di Monterosato, 1874 -- valid -- granulose cleftclam
  Thyasira rotunda Jeffreys, 1881 -- valid -- rotund cleftclam
  Thyasira simplex A. E. Verrill and Bush, 1898 -- valid -- simple cleftclam
  Thyasira succisa (Jeffreys, 1876) -- valid -- cut-off cleftclam
  Thyasira trisinuata (d'Orbigny, 1842) -- valid -- atlantic cleftcla, Atlantic cleftclam
  Thyasiridae Dall, 1901 -- valid
  Thyonicola Mandahl-Barth, 1941 -- valid
  Thyonicola americana Tikasingh, 1961 -- valid
  Thysanophora Strebel and Pfeffer, 1880 -- valid
  Thysanophora hornii (Gabb, 1866) -- valid -- southwestern fringed-snail
  Thysanophora plagioptycha (Shuttleworth, 1854) -- valid -- lyrate fringed snail, lyrate fringed-snail
  Thysanophoridae Pilsbry, 1926 -- valid
  Thysanoteuthis rhombus Troschel, 1857 -- valid -- diamond squid
  Timoclea Brown, 1827 -- valid
  Timoclea grus (Holmes, 1858) -- valid -- gray pygmy-venus
  Timoclea pygmaea (Lamarck, 1818) -- valid -- pygmy-venus
  Tivela Link, 1807 -- valid
  Tivela abaconis Dall, 1902 -- valid -- Abaco tivela
  Tivela floridana Rehder, 1939 -- valid -- Florida tivela
  Tivela mactroides (Born, 1778) -- valid -- trigonal tivela
  Tivela stultorum (Mawe, 1823) -- valid -- Pismo clam
  Tochuina Odhner, 1963 -- valid
  Tochuina tetraquetra (Pallas, 1788) -- valid -- giant orange tochui
  Tomura Pilsbry and McGinty, 1946 -- valid
  Tomura bicaudata (Pilsbry and McGinty, 1946) -- valid -- two-tail vitrinella
  Tonicella Carpenter, 1873 -- valid
  Tonicella beringensis Kakovleva, 1952 -- invalid
  Tonicella blaneyi Dall, 1905 -- invalid
  Tonicella granulata Yakovleva, 1952 -- invalid
  Tonicella insignis (Reeve, 1847) -- valid
  Tonicella lineata (W. Wood, 1815) -- valid
  Tonicella marmorea (Fabricius, 1780) -- valid
  Tonicella rubra (Linnaeus, 1767) -- valid -- northern red chiton
  Tonicella saccharina Dall, 1878 -- invalid
  Tonicella submarmorea (Middendorff, 1847) -- invalid
  Tonicella undocarulea Sirenko, 1973 -- invalid
  Tonicellidae Simroth, 1894 -- invalid
  Tonicia Gray, 1847 -- valid
  Tonicia pustulifera Dall, 1919 -- valid
  Tonicia schrammi (Shuttleworth, 1856) -- valid -- gold-flecked chiton
  Tonna Brunnich, 1772 -- valid
  Tonna galea (Linnaeus, 1758) -- valid -- giant tun
  Tonna pennata (Morch, 1852) -- valid -- Atlantic partridge tun
  Tonnidae Peile, 1926 -- invalid
  Torellia Lovén in Jeffreys, 1867 -- valid
  Torellia ammonia Dall, 1919 -- valid -- rams-horn hairysnail
  Torellia delicata (Philippi, 1844) -- valid -- veiled hairysnail
  Torellia vallonia Dall, 1919 -- valid -- acorn hairysnail
  Tornatina A. Adams, 1850 -- valid
  Tornatina inconspicua (Olsson and McGinty, 1958) -- valid
  Tornidae Sacco, 1896 -- valid
  Tornus Turton and Kingston, 1830 -- valid
  Tornus calianus (Dall, 1919) -- valid
  Toxolasma Rafinesque, 1831 -- valid
  Toxolasma corvunculus (Lea, 1868) -- valid -- southern purple lilliput
  Toxolasma cylindrellus (Lea, 1868) -- valid -- pale lilliput, pale lilliput pearly mussel
  Toxolasma lividus Rafinesque, 1831 -- invalid -- purple lilliput
  Toxolasma mearnsi (Simpson, 1900) -- invalid -- western lilliput
  Toxolasma parvus (Barnes, 1823) -- invalid -- lilliput
  Toxolasma paulus (Lea, 1840) -- invalid -- iridescent lilliput
  Toxolasma pullus (Conrad, 1838) -- valid -- Savannah lilliput
  Toxolasma texasensis (Lea, 1857) -- invalid -- Texas lilliput
  Toxolasma texasiense (Lea, 1857) -- valid -- Texas lilliput
  Toxolasma texasiensis (Lea, 1857) -- invalid -- Texas lilliput
  Trabecula di Monterosato, 1884 -- valid
  Trabecula laxa (Dall and Bartsch, 1909) -- valid
  Trachycardium Morch, 1853 -- valid
  Trachycardium egmontianum (Shuttleworth, 1856) -- valid -- Florida pricklycockle
  Trachycardium magnum (Linnaeus, 1758) -- valid -- magnum pricklycockle
  Trachycardium muricatum (Linnaeus, 1758) -- valid -- yellow pricklycockle
  Trachycardium quadragenarium (Conrad, 1837) -- valid -- spiny pricklycockle
  Trachypollia Woodring, 1928 -- valid
  Trachypollia lugubris (C. B. Adams, 1852) -- valid -- dark drupe
  Trachypollia nodulosa (C. B. Adams, 1845) -- valid -- blackberry drupe
  Trachypollia sclera Woodring, 1928 -- valid
  Trachypollia turricula (von Maltzan, 1884) -- valid -- twin drupe
  Tralia Gray, 1840 -- valid
  Tralia ovula (Bruguiere, 1789) -- valid -- egg melampus
  Transennella Dall, 1883 -- valid
  Transennella confusa S. Gray, 1982 -- invalid -- confusing transennella
  Transennella conradina Dall, 1884 -- valid -- Conrad transennella, colorful transennella
  Transennella cubaniana (d'Orbigny, 1842) -- valid -- Cuba transennella
  Transennella stimpsoni Dall, 1902 -- valid -- Stimpson transennella, banded transennella
  Trapania Pruvot-Fol, 1931 -- valid
  Trapania dalva Ev. Marcus, 1972 -- valid
  Trapania velox (Cockerell, 1901) -- valid
  Trapezidae Lamy, 1920 -- valid
  Trapeziidae Lamy, 1920 -- invalid
  Trapezium Muhlfeld, 1811 -- valid
  Tremoctopus violaceus Chiaie, 1830 in 1823-1831 -- valid -- common blanket octopus
  Tresus Gray, 1853 -- valid
  Tresus capax (Gould, 1850) -- valid -- fat gaper
  Tresus nuttallii (Conrad, 1837) -- valid -- Pacific gaper
  Tresus pajaroanus (Conrad, 1857) -- valid -- lost gaper
  Trichia Hartmann, 1841 -- valid
  Trichia hispida (Linnaeus, 1758) -- valid -- hairy helicellid
  Trichia striolata (Pfeiffer, 1828) -- valid -- furrowed helicellid
  Trichotropis Broderip and G. B. Sowerby I, 1829 -- valid
  Trichotropis bicarinata (G. B. Sowerby I, 1825) -- valid -- two-keel hairysnail
  Trichotropis borealis Broderip and G. B. Sowerby I, 1829 -- valid -- boreal hairysnail
  Trichotropis cancellata Hinds, 1843 -- valid -- cancellate hairysnail
  Trichotropis conica Moller, 1842 -- valid
  Trichotropis coronata Gould, 1860 -- valid -- crowned hairysnail
  Trichotropis insignis Middendorff, 1849 -- valid -- gray hairysnail
  Trichotropis kroyeri Philippi, 1849 -- valid
  Trichotropis migrans Dall, 1881 -- valid -- wandering hairysnail
  Tridachia Deshayes, 1857 -- invalid
  Tridachia crispata (Mørch, 1863) -- invalid -- lettuce slug
  Tridonta Schumacher, 1817 -- invalid
  Tridonta alaskensis (Dall, 1903) -- invalid -- alaska tridonta
  Tridonta arctica (J. E. Gray, 1824) -- invalid -- arctic tridonta
  Tridonta bennettii (Dall, 1903) -- invalid -- bennett tridonta
  Tridonta borealis Schumacher, 1817 -- invalid -- boreal tridonta
  Tridonta elliptica (T. Brown, 1827) -- invalid
  Tridonta filatovae (Habe, 1964) -- invalid -- filatova tridonta
  Tridonta montagui (Dillwyn, 1817) -- invalid -- montagu tridonta
  Tridonta rollandi (Bernardi, 1859) -- invalid -- rolland tridonta
  Tridonta vernicosa (Dall, 1903) -- invalid -- varnished tridonta
  Trigonostoma de Blainville, 1825 -- valid
  Trigonostoma rugosum (Lamarck, 1822) -- valid -- rugose nutmeg
  Trigonostoma tenerum (Philippi, 1848) -- valid
  Trigonulina D'Orbigny, 1842 -- valid
  Trigonulina ornata (d'Orbigny, 1842) -- valid -- ornate verticord
  Trilobopsis Pilsbry, 1939 -- valid
  Trilobopsis loricata (Gould, 1846) -- valid -- scaley chaparral, scaly chaparral
  Trilobopsis penitens (Hanna and Rixford, 1923) -- valid -- Mormon Island chaparral
  Trilobopsis roperi (Pilsbry, 1889) -- valid -- Shasta chaparral
  Trilobopsis tehamana (Pilsbry, 1928) -- valid -- Tehama chaparral
  Trilobopsis trachypepla (S. S. Berry, 1933) -- valid -- Bridge Creek chaparral
  Trimusculidae J. Q. Burch, 1945 -- valid
  Trimusculus Schmidt, 1818 -- valid
  Trimusculus carinatus (Dall, 1870) -- valid -- carinate gadinia
  Trimusculus reticulatus (G. B. Sowerby I, 1835) -- valid -- reticulate gadinia
  Triodopsis Rafinesque, 1819 -- valid
  Triodopsis alabamensis (Pilsbry, 1902) -- valid -- alabama three-tooth, Alabama threetooth
  Triodopsis anteridon Pilsbry, 1940 -- valid -- Carter threetooth
  Triodopsis burchi Hubricht, 1950 -- valid -- pittsylvania three-tooth, Pittsylvania threetooth
  Triodopsis claibornensis Lutz, 1950 -- valid -- claiborne three-tooth, Claiborne threetooth
  Triodopsis complanata (Pilsbry, 1898) -- valid -- glossy three-tooth, glossy threetooth
  Triodopsis cragini Call, 1886 -- valid -- post oak three-tooth, Post Oak threetooth
  Triodopsis discoidea (Pilsbry, 1904) -- valid -- rivercliff three-tooth, rivercliff threetooth
  Triodopsis fallax (Say, 1825) -- valid -- pinhole three-tooth, mimic threetooth
  Triodopsis fradulenta (Pilsbry, 1894) -- valid -- baffled three-tooth, baffled threetooth
  Triodopsis fulciden Hubricht, 1952 -- valid -- dwarf threetooth
  Triodopsis henriettae (Mazyck, 1877) -- valid -- pineywood three-tooth, pineywoods threetooth
  Triodopsis hopetonensis (Shuttleworth, 1852) -- valid -- magnolia three-tooth, magnolia threetooth
  Triodopsis juxtidens (Pilsbry, 1894) -- valid -- atlantic three-tooth, Atlantic threetooth
  Triodopsis messana Hubricht, 1952 -- valid -- pinhole three-tooth, pinhole threetooth
  Triodopsis neglecta (Pilsbry, 1899) -- valid -- ozark three-tooth, Ozark threetooth
  Triodopsis obsoleta (Pilsbry, 1894) -- valid -- nubbin three-tooth, nubbin threetooth
  Triodopsis palustris Hubricht, 1958 -- valid -- santee three-tooth, Santee threetooth
  Triodopsis pendula Hubricht, 1952 -- valid -- hanging rock three-tooth, Hanging Rock threetooth
  Triodopsis picea Hubricht, 1958 -- valid -- spruce knob three-tooth, Spruce Knob threetooth
  Triodopsis platysayoides (Brooks, 1933) -- valid -- cheat three-tooth, flat-spired three-toothed snail, Cheat threetooth
  Triodopsis rugosa Brooks and MacMillan, 1940 -- valid -- buttressed three-tooth, buttressed threetooth
  Triodopsis soelneri (J. B. Henderson, 1907) -- valid -- cape fear three-tooth, Cape Fear threetooth
  Triodopsis tennesseensis (Walker and Pilsbry, 1902) -- valid -- budded three-tooth, budded threetooth
  Triodopsis tridentata (Say, 1816) -- valid -- northern three-tooth, northern threetooth
  Triodopsis vannostrandi (Bland, 1875) -- valid -- tight-coil three-tooth, coiled threetooth
  Triodopsis vulgata Pilsbry, 1940 -- valid -- dished three-tooth, dished threetooth
  Triodopsis vultuosa (Gould, 1848) -- valid -- texas three-tooth, Texas threetooth
  Triopha Bergh, 1880 -- valid
  Triopha catalinae (J. G. Cooper, 1863) -- valid -- sea-clown triopha
  Triopha maculata MacFarland, 1905 -- valid -- maculated triopha
  Triopha occidentalis (Fewkes, 1889) -- valid -- grand triopha
  Triphora de Blainville, 1828 -- valid
  Triphora callipyrga (Bartsch, 1907) -- valid
  Triphora calva Faber and Moolenbeek, 1991 -- valid
  Triphora carpenteri (Bartsch, 1907) -- valid
  Triphora catalinensis (Bartsch, 1907) -- valid
  Triphora compsa Dall, 1927 -- valid
  Triphora intermedia (Dall, 1881) -- valid
  Triphora lilacina (Dall, 1889) -- valid
  Triphora longissima (Dall, 1881) -- valid
  Triphora montereyensis (Bartsch, 1907) -- valid
  Triphora ornata (Deshayes, 1832) -- valid
  Triphora pedroana (Bartsch, 1907) -- valid -- San Pedro triphora
  Triphora peninsularis (Bartsch, 1907) -- valid
  Triphora pyrrha (J. B. Henderson and Bartsch, 1914) -- valid
  Triphora stearnsi (Bartsch, 1907) -- valid
  Triphora triserialis (Dall, 1881) -- valid
  Triphoridae Gray, 1847 -- valid
  Triptychus Morch, 1875 -- valid
  Triptychus niveus Morch, 1875 -- valid
  Tritogonia Agassiz, 1852 -- invalid
  Tritogonia verrucosa (Rafinesque, 1820) -- invalid -- pistolgrip
  Tritonia Cuvier, 1798 -- valid
  Tritonia bayeri Ev. Marcus and Er. Marcus, 1967 -- valid
  Tritonia bayeri bayeri Ev. Marcus and Er. Marcus, 1967 -- valid
  Tritonia bayeri misa Ev. Marcus and Er. Marcus, 1967 -- valid
  Tritonia diomedea Bergh, 1894 -- valid -- rosy tritonia
  Tritonia festiva (Stearns, 1873) -- valid -- diamondback tritonia
  Tritonia myrakeenae Bertsch and Mozqueira, 1986 -- valid
  Tritonia plebeia Johnston, 1828 -- valid
  Tritonidoxa Bergh, 1907 -- valid
  Tritonidoxa wellsi (Er. Marcus, 1961) -- valid
  Tritoniidae Menke, 1828 -- invalid
  Tritoniopsis Eliot, 1905 -- valid
  Tritoniopsis frydis Er. Marcus and Ev. Marcus, 1970 -- valid
  Tritonoharpa Dall, 1908 -- valid
  Tritonoharpa lanceolata (Menke, 1828) -- valid -- arrow dwarf triton
  Triviidae Trochel, 1863 -- valid
  Trochidae Rafinesque, 1815 -- valid
  Trochoidea Brown, 1827 -- valid
  Trochoidea elegans (Gmelin, 1791) -- valid -- elegant helicellid
  Trophonopsis Bucquoy, Dautzenberg and Dollfus, 1882 -- valid
  Trophonopsis fabricii (Beck, 1842) -- valid
  Truncatella Risso, 1826 -- valid
  Truncatella californica Pfeiffer, 1857 -- valid -- California truncatella
  Truncatella caribaeensis Reeve, 1842 -- valid -- Caribbean truncatella
  Truncatella clathrus Lowe, 1932 -- valid
  Truncatella pulchella Pfeiffer, 1839 -- valid -- beautiful truncatella
  Truncatella stimpsonii Stearns, 1872 -- valid
  Truncatellidae Gray, 1840 -- valid
  Truncilla Rafinesque, 1819 -- valid
  Truncilla cognata (Lea, 1860) -- valid -- Mexican fawnsfoot
  Truncilla donaciformis (Lea, 1828) -- valid -- fawnsfoot
  Truncilla macrodon (Lea, 1859) -- valid -- Texas fawnsfoot
  Truncilla truncata Rafinesque, 1820 -- valid -- deertoe
  Tryblidiida -- valid
  Tryonia Stimpson, 1865 -- valid
  Tryonia adamantina Taylor, 1987 -- invalid -- Diamond tryonia
  Tryonia aequicostata (Pilsbry, 1890) -- valid -- Smooth-rib Hydrobe, Smooth-ribbed Hydrobe
  Tryonia angulata Hershler and Sada, 1987 -- valid -- Sportinggoods Tryonia
  Tryonia brevissima (Pilsbry, 1890) -- invalid -- regal hydrobe
  Tryonia brunei Taylor, 1987 -- valid -- Brune's Springsnail
  Tryonia cheatumi (Pilsbry, 1935) -- valid -- Phantom Tryonia
  Tryonia circumstriata (Leonard and Ho, 1960) -- valid -- Gonzales Springsnail
  Tryonia clathrata Stimpson, 1865 -- valid -- Grated Tryonia
  Tryonia diaboli (Pilsbry and Ferriss, 1906) -- valid -- Devil Tryonia
  Tryonia elata Hershler and Sada, 1987 -- valid -- Point of Rocks Tryonia
  Tryonia ericae Hershler and Sada, 1987 -- valid -- Minute Tryonia
  Tryonia gilae Taylor, 1987 -- valid -- Gila Tryonia
  Tryonia imitator (Pilsbry, 1899) -- valid -- Mimic Tryonia
  Tryonia kosteri Taylor, 1987 -- invalid -- Sago tryonia
  Tryonia margae Hershler, 1989 -- valid -- Grapevine Springs Elongate Tryonia
  Tryonia protea (Gould, 1855) -- invalid -- desert tryonia
  Tryonia quitobaquitae Hershler, 1988 -- valid -- Quitobaquito Tryonia
  Tryonia robusta Hershler, 1989 -- invalid
  Tryonia rowlandsi Hershler, 1989 -- valid -- Grapevine Springs Squat Tryonia
  Tryonia salina Hershler, 1989 -- valid -- Cottonball Marsh Tryonia
  Tryonia variegata Hershler and Sada, 1987 -- valid -- Amargosa Tryonia
  Tulotoma Haldeman, 1840 -- valid
  Tulotoma magnifica (Conrad, 1834) -- valid -- Alabama live-bearing snail, Tulotoma
  Turbinellidae Swainson, 1835 -- valid
  Turbinidae Rafinesque, 1815 -- valid
  Turbo Linnaeus, 1758 -- valid
  Turbo cailletii P. Fischer and Bernardi, 1856 -- valid -- filose turban
  Turbo canaliculatus Hermann, 1781 -- valid -- channeled turban
  Turbo castanea Gmelin, 1791 -- valid -- chestnut turban
  Turbonilla Risso, 1826 -- valid
  Turbonilla acra Dall and Bartsch, 1909 -- valid
  Turbonilla adusta Dall and Bartsch, 1909 -- valid
  Turbonilla aepynota Dall and Bartsch, 1909 -- valid
  Turbonilla aequalis (Say, 1827) -- valid
  Turbonilla alaskana Dall and Bartsch, 1909 -- valid
  Turbonilla almo Dall and Bartsch, 1909 -- valid
  Turbonilla antestriata Dall and Bartsch, 1907 -- valid
  Turbonilla aragoni Dall and Bartsch, 1909 -- valid
  Turbonilla aresta Dall and Bartsch, 1909 -- valid
  Turbonilla attrita Dall and Bartsch, 1909 -- valid
  Turbonilla aurantia (Carpenter, 1864) -- valid
  Turbonilla auricoma Dall and Bartsch, 1903 -- valid
  Turbonilla bakeri Bartsch, 1912 -- valid
  Turbonilla barkleyensis Bartsch, 1917 -- valid
  Turbonilla belotheca Dall, 1889 -- valid
  Turbonilla burchi M. Gordon, 1938 -- valid
  Turbonilla buteonis Bartsch, 1909 -- valid
  Turbonilla callia Dall and Bartsch, 1909 -- valid
  Turbonilla callimene Bartsch, 1912 -- valid
  Turbonilla canadensis Bartsch, 1917 -- valid
  Turbonilla canfieldi Dall and Bartsch, 1907 -- valid
  Turbonilla carpenteri Dall and Bartsch, 1909 -- valid
  Turbonilla castanea (Keep, 1887) -- valid
  Turbonilla castanella Dall, 1908 -- valid
  Turbonilla chocolata (Carpenter, 1864) -- valid
  Turbonilla clarinda Bartsch, 1912 -- valid
  Turbonilla clementina Bartsch, 1927 -- valid
  Turbonilla conradi Bush, 1899 -- valid
  Turbonilla coomansi Van Aartsen, 1994 -- valid
  Turbonilla curta Dall, 1889 -- valid
  Turbonilla dalli Bush, 1899 -- valid
  Turbonilla delmontana Bartsch, 1937 -- valid
  Turbonilla diegensis Dall and Bartsch, 1909 -- valid
  Turbonilla dinora Bartsch, 1912 -- valid
  Turbonilla dora Bartsch, 1917 -- valid
  Turbonilla dracona Bartsch, 1912 -- valid
  Turbonilla edwardensis Bartsch, 1909 -- valid
  Turbonilla elegantula A. E. Verrill, 1882 -- valid
  Turbonilla encella Bartsch, 1912 -- valid
  Turbonilla engbergi Bartsch, 1920 -- valid
  Turbonilla enna Bartsch, 1927 -- valid
  Turbonilla eschscholtzi Dall and Bartsch, 1907 -- valid
  Turbonilla eucosmobasis Dall and Bartsch, 1907 -- valid
  Turbonilla eva Bartsch, 1917 -- valid
  Turbonilla exilis (C. B. Adams, 1850) -- valid
  Turbonilla eyerdami Bartsch, 1927 -- valid
  Turbonilla fackenthallae A. G. Smith and M. Gordon, 1948 -- valid
  Turbonilla franciscana Bartsch, 1917 -- valid
  Turbonilla gabbiana (J. G. Cooper, 1867) -- valid
  Turbonilla gilli Dall and Bartsch, 1907 -- valid
  Turbonilla gilli delmontensis Dall and Bartsch, 1907 -- valid
  Turbonilla gilli gilli Dall and Bartsch, 1907 -- valid
  Turbonilla gloriosa Bartsch, 1912 -- valid
  Turbonilla grippi Bartsch, 1912 -- valid
  Turbonilla halibrecta Dall and Bartsch, 1909 -- valid
  Turbonilla halistrepta Dall and Bartsch, 1909 -- valid
  Turbonilla hecuba Dall and Bartsch, 1913 -- valid
  Turbonilla hemphilli Bush, 1899 -- valid
  Turbonilla hypolispa Dall and Bartsch, 1909 -- valid
  Turbonilla ilfa Bartsch, 1927 -- valid
  Turbonilla ina Bartsch, 1917 -- valid
  Turbonilla interrupta (Totten, 1835) -- valid
  Turbonilla ista Bartsch, 1917 -- valid
  Turbonilla jewetti Dall and Bartsch, 1909 -- valid
  Turbonilla kelseyi Dall and Bartsch, 1909 -- valid
  Turbonilla kincaidi Bartsch, 1921 -- valid
  Turbonilla laminata (Carpenter, 1864) -- valid
  Turbonilla levis (C. B. Adams, 1850) -- valid
  Turbonilla lituyana Dall and Bartsch, 1909 -- valid
  Turbonilla lordii (E. A. Smith, 1880) -- valid
  Turbonilla louiseae Clarke, 1954 -- valid
  Turbonilla lyalli Dall and Bartsch, 1907 -- valid
  Turbonilla macouni Dall and Bartsch, 1910 -- valid
  Turbonilla middendorffi Bartsch, 1927 -- valid
  Turbonilla mighelsi Bartsch, 1909 -- valid
  Turbonilla morchi Dall and Bartsch, 1907 -- valid
  Turbonilla multicostata (C. B. Adams, 1850) -- valid
  Turbonilla muricatoides Dall and Bartsch, 1907 -- valid
  Turbonilla nereia Dall and Bartsch, 1909 -- valid
  Turbonilla newcombei Dall and Bartsch, 1907 -- valid
  Turbonilla nivea (Stimpson, 1851) -- valid
  Turbonilla nuttingi Dall and Bartsch, 1909 -- valid
  Turbonilla obeliscus (C. B. Adams, 1850) -- valid
  Turbonilla obesa Dall and Bartsch, 1909 -- valid
  Turbonilla oregonensis Dall and Bartsch, 1907 -- valid
  Turbonilla pauli A. G. Smith and M. Gordon, 1958 -- valid
  Turbonilla pentalopha Dall and Bartsch, 1903 -- valid
  Turbonilla perlepida A. E. Verrill, 1885 -- valid
  Turbonilla pesa Dall and Bartsch, 1910 -- valid
  Turbonilla pluto Dall and Bartsch, 1909 -- valid
  Turbonilla pocahontasae J. B. Henderson and Bartsch, 1914 -- valid
  Turbonilla powhatani J. B. Henderson and Bartsch, 1914 -- valid
  Turbonilla protracta Dall, 1892 -- valid
  Turbonilla pugetensis Bartsch, 1917 -- valid
  Turbonilla puncta (C. B. Adams, 1850) -- valid
  Turbonilla punicea Dall, 1884 -- valid
  Turbonilla pupoides D'Orbigny, 1842 -- valid
  Turbonilla rathbuni A. E. Verrill and S. Smith, 1880 -- valid
  Turbonilla raymondi Dall and Bartsch, 1909 -- valid
  Turbonilla recta Dall and Bartsch, 1909 -- valid
  Turbonilla reticulata (C. B. Adams, 1850) -- valid
  Turbonilla ridgwayi Dall and Bartsch, 1909 -- valid
  Turbonilla riisei Morch, 1875 -- valid
  Turbonilla rinella Dall and Bartsch, 1910 -- valid
  Turbonilla santarosana Dall and Bartsch, 1909 -- valid
  Turbonilla serrae Dall and Bartsch, 1907 -- valid
  Turbonilla shuyakensis Bartsch, 1927 -- valid
  Turbonilla signae Dall and Bartsch, 1909 -- valid
  Turbonilla simpsoni Dall and Bartsch, 1909 -- valid
  Turbonilla stelleri Bartsch, 1927 -- valid
  Turbonilla stillmani A. G. Smith and M. Gordon, 1948 -- valid
  Turbonilla stimpsoni Bush, 1899 -- valid
  Turbonilla stricta A. E. Verrill, 1873 -- valid
  Turbonilla strongi Willett, 1931 -- valid
  Turbonilla stylina (Carpenter, 1864) -- valid
  Turbonilla subulata (C. B. Adams, 1850) -- valid
  Turbonilla sumneri Bartsch, 1909 -- valid
  Turbonilla swani Dall and Bartsch, 1909 -- valid
  Turbonilla talma Dall and Bartsch, 1910 -- valid
  Turbonilla taylori Dall and Bartsch, 1907 -- valid
  Turbonilla tenuicula (Gould, 1853) -- valid
  Turbonilla textilis (Kurtz, 1860) -- valid
  Turbonilla torquata (Gould, 1853) -- valid
  Turbonilla toyatani J. B. Henderson and Bartsch, 1914 -- valid
  Turbonilla tremperi Bartsch, 1917 -- valid
  Turbonilla tridentata (Carpenter, 1864) -- valid
  Turbonilla valida A. E. Verrill and Bush, 1900 -- valid
  Turbonilla vancouverensis (Baird, 1863) -- valid
  Turbonilla verrilli Bartsch, 1909 -- valid
  Turbonilla vexativa Dall and Bartsch, 1909 -- valid
  Turbonilla virga Dall, 1884 -- valid
  Turbonilla virgata Dall, 1892 -- valid
  Turbonilla virginica J. B. Henderson and Bartsch, 1914 -- valid
  Turbonilla virgo (Carpenter, 1864) -- valid
  Turbonilla viridaria Dall, 1884 -- valid
  Turbonilla weldi Dall and Bartsch, 1909 -- valid
  Turbonilla whiteavesi Bartsch, 1909 -- valid
  Turbonilla wickhami Dall and Bartsch, 1909 -- valid
  Turbonilla willetti A. G. Smith and M. Gordon, 1948 -- valid
  Turbonilla wrightsvillensis Powell, 1981 -- valid
  Turcica A. Adams, 1854 -- valid
  Turcica caffea (Gabb, 1865) -- valid -- two-tooth topsnail
  Turridae H. Adams and A. Adams, 1853 -- valid
  Turritella Lamarck, 1799 -- valid
  Turritella acropora Dall, 1889 -- valid -- boring turretsnail
  Turritella cooperi Carpenter, 1864 -- valid -- symmetrical turretsnail
  Turritella exoleta (Linnaeus, 1758) -- valid -- eastern turretsnail
  Turritella lindae Petuch, 1987 -- valid
  Turritella mariana Dall, 1908 -- valid
  Turritella variegata (Linnaeus, 1758) -- valid -- variegate turretsnail
  Turritellidae Clarke, 1851 -- invalid
  Turritellopsis G. O. Sars, 1878 -- valid
  Turritellopsis stimpsoni Dall, 1919 -- valid -- needle turretsnail
  Turtonia minuta (Fabricius, 1780) -- valid -- minute turton
  Turtonia occidentalis Dall, 1871 -- invalid -- western turton
  Turtoniidae W. Clark, 1855 -- invalid
  Tylodina Rafinesque, 1814 -- valid
  Tylodina americana Dall, 1890 -- valid
  Tylodina fungina Gabb, 1865 -- valid -- yellow umbrella slug
  Tylodinidae Gray, 1847 -- valid
  Typhinellus Jousseaume, 1880 -- valid
  Typhinellus sowerbii (Broderip, 1833) -- valid -- frilly typhis
  Typhlomangelia G. O. Sars, 1878 -- valid
  Typhlomangelia nivalis (Loven, 1846) -- valid
  Udosarx Webb, 1954 -- valid
  Udosarx lyrata Webb, 1959 -- valid -- lyre mantleslug
  Umbilibalcis Bouchet and Waren, 1986 -- valid
  Umbilibalcis lata (Dall, 1889) -- valid -- wide aclis
  Umbraculidae Dall, 1889 -- valid
  Umbraculum Schumacher, 1817 -- valid
  Umbraculum umbraculum (Lightfoot, 1786) -- valid -- Atlantic umbrella slug
  Unela Er. Marcus, 1953 -- valid
  Unela nahantensis Doe, 1974 -- valid
  Unela remanei Er. Marcus, 1953 -- valid -- sand nudibranch, sand slug
  Ungulinidae Gray, 1854 -- valid
  Uniomerus Conrad, 1853 -- valid
  Uniomerus caroliniana (Bosc, 1801) -- invalid -- Florida pondhorn
  Uniomerus carolinianus (Bosc, 1801) -- valid -- Florida pondhorn, eastern pondhorn
  Uniomerus declivis (Say, 1831) -- valid -- tapered pondhorn
  Uniomerus obesus (Lea, 1831) -- invalid -- southern pondhorn
  Uniomerus tetralasmus (Say, 1831) -- valid -- pondhorn
  Unionidae Rafinesque, 1820 -- valid
  Unionoida Stoliczka, 1871 -- invalid
  Urocoptidae Pilsbry, 1898 -- valid
  Urosalpinx Stimpson, 1865 -- valid
  Urosalpinx cinerea (Say, 1822) -- valid -- Atlantic oyster drill
  Urosalpinx macra A. E. Verrill, 1884 -- valid -- waxy drill
  Urosalpinx perrugata (Conrad, 1846) -- valid -- Gulf oyster drill
  Urosalpinx subangulata (Stearns, 1873) -- valid
  Urosalpinx tampaensis (Conrad, 1846) -- valid -- Tampa drill
  Utterbackia F. C. Baker, 1927 -- valid
  Utterbackia heardi (Gordon & Hoeh, 1995) -- invalid -- Apalachicola floater
  Utterbackia imbecillis (Say, 1829) -- valid -- paper pondshell
  Utterbackia peggyae (R. I. Johnson, 1965) -- valid -- Florida floater
  Utterbackia peninsularis Bogan & Hoeh, 1995 -- valid -- peninsular floater
  Vallonia Risso, 1826 -- valid
  Vallonia albula Sterki, 1893 -- valid -- indecisive vallonia
  Vallonia costata (Muller, 1774) -- valid -- costate vallonia
  Vallonia cyclophorella Sterki, 1892 -- valid -- silky vallonia
  Vallonia excentrica Sterki, 1893 -- valid -- Iroquois vallonia
  Vallonia gracilicosta Reinhardt, 1883 -- valid -- multiribbed vallonia, multirib vallonia
  Vallonia parvula Sterki, 1893 -- valid -- trumpet vallonia
  Vallonia perspectiva Sterki, 1893 -- valid -- thin-lip vallonia
  Vallonia pulchella (Muller, 1774) -- valid -- lovely vallonia
  Vallonia terraenovae Gerber, 1996 -- valid -- Terre-Neuve vallonia
  Valloniidae Morse, 1864 -- valid
  Valvata O. F. Muller, 1774 -- valid
  Valvata bicarinata Lea, 1841 -- valid -- Two-ridge Valvata
  Valvata humeralis Say, 1829 -- valid -- Glossy Valvata
  Valvata lewisi Currier, 1868 -- valid -- Fringed Valvata
  Valvata mergella Westerlund, 1883 -- valid -- Rams-horn Valvata
  Valvata perdepressa Walker, 1906 -- valid -- Purplecap Valvata
  Valvata piscinalis (Muller, 1774) -- valid -- European stream valvata
  Valvata sincera Say, 1824 -- valid -- Mossy Valvata
  Valvata tricarinata (Say, 1817) -- valid -- Threeridge Valvata
  Valvata utahensis Call, 1884 -- valid -- Desert Valvata
  Valvata virens Tryon, 1863 -- valid -- Emerald Valvata
  Valvata winnebagoensis F. C. Baker, 1928 -- valid -- Flanged Valvata
  Valvatidae Gray, 1840 -- valid -- valve snails
  Vanikoridae Gray, 1840 -- valid
  Vanikoro Quoy and Gaimard, 1832 -- valid
  Vanikoro oxychone Morch, 1877 -- valid -- West Indian vanikoro
  Varicopeza Grundel, 1976 -- valid
  Varicopeza crystallina (Dall, 1881) -- valid
  Varicorbula Grant and Gale, 1931 -- valid
  Varicorbula operculata (Philippi, 1848) -- valid -- oval varicorbula
  Vasum Roding, 1798 -- valid
  Vasum muricatum (Born, 1778) -- valid -- Caribbean vase
  Velutina Fleming, 1820 -- valid
  Velutina conica Dall, 1887 -- valid -- conical lamellaria
  Velutina granulata Dall, 1919 -- valid -- granular lamellaria
  Velutina lanigera Moller, 1842 -- valid -- wooly lamellaria
  Velutina plicatilis (Muller, 1776) -- valid -- oblique lamellaria
  Velutina prolongata Carpenter, 1864 -- valid -- elongate lamellaria
  Velutina rubra Willett, 1919 -- valid -- red lamellaria
  Velutina undata (T. Brown, 1839) -- valid -- wavy lamellaria
  Velutina velutina (Muller, 1776) -- valid -- smooth lamellaria
  Velutinidae Gray, 1840 -- valid
  Veneridae Rafinesque, 1815 -- valid
  Veneroida -- invalid
  Venerupis Lamarck, 1818 -- valid
  Venerupis philippinarum (A. Adams and Reeve, 1850) -- valid -- Japanese littleneck
  Ventricolaria Keen, 1954 -- invalid
  Ventricolaria foresti Fischer-Piette and Testud, 1967 -- invalid
  Ventricolaria listeroides Fischer-Piette and Testud, 1967 -- invalid
  Ventricolaria rigida (Dillwyn, 1817) -- invalid -- rigid venus
  Ventricolaria rugatina (Heilprin, 1886) -- invalid -- queen venus
  Ventridens Binney and Bland, 1869 -- valid
  Ventridens acerra (J. Lewis, 1870) -- valid -- glossy dome
  Ventridens arcellus Hubricht, 1976 -- valid -- golden dome
  Ventridens brittsi (Pilsbry, 1892) -- valid -- western dome
  Ventridens cerinoideus (Anthony, 1865) -- valid -- wax dome
  Ventridens coelaxis (Pilsbry, 1899) -- valid -- bidentate dome
  Ventridens collisella (Pilsbry, 1896) -- valid -- sculptured dome
  Ventridens decussatus (Walker and Pilsbry, 1902) -- valid -- crossed dome
  Ventridens demissus (A. Binney, 1843) -- valid -- perforate dome
  Ventridens eutropis Pilsbry, 1946 -- valid -- carinate dome
  Ventridens gularis (Say, 1822) -- valid -- throaty dome
  Ventridens intertextus (A. Binney, 1841) -- valid -- pyramid dome
  Ventridens lasmodon (Phillips, 1841) -- valid -- hollow dome
  Ventridens lawae (W. G. Binney, 1892) -- valid -- rounded dome
  Ventridens ligera (Say, 1821) -- valid -- globose dome
  Ventridens monodon Hubricht, 1964 -- valid -- blade dome
  Ventridens percallosus (Pilsbry, 1898) -- valid -- Tennessee dome
  Ventridens pilsbryi Hubricht, 1964 -- valid -- yellow dome
  Ventridens suppressus (Say, 1829) -- valid -- flat dome
  Ventridens theloides (Walker and Pilsbry, 1902) -- valid -- copper dome
  Ventridens virginicus (Vanatta, 1936) -- valid -- split-tooth dome
  Ventridens volusiae (Pilsbry, 1900) -- valid -- Seminole dome
  Venustaconcha Frierson, 1927 -- valid
  Venustaconcha ellipsiformis (Conrad, 1836) -- valid -- ellipse
  Venustaconcha pleasi (Marsh, 1891) -- invalid -- bleedingtooth mussel
  Venustaconcha pleasii (Marsh, 1891) -- valid -- bleedingtooth mussel
  Vermetidae Rafinesque, 1815 -- valid
  Vermicularia Lamarck, 1799 -- valid
  Vermicularia fargoi Olsson, 1951 -- valid
  Vermicularia fewkesi (Yates, 1890) -- valid
  Vermicularia knorrii (Deshayes, 1843) -- valid -- Florida wormsnail
  Vermicularia radicula (Stimpson, 1851) -- valid -- northern wormsnail
  Vermicularia spirata (Philippi, 1836) -- valid -- West Indian wormsnail
  Veronicella de Blainville, 1817 -- valid
  Veronicella sloanii (Cuvier, 1817) -- valid
  Veronicellidae Gray, 1840 -- valid
  Verticordia J. de C. Sowerby, 1844 -- valid
  Verticordia granulata Seguenza, 1876 -- valid -- trapezoid verticord
  Verticordiidae Stoliczka, 1871 -- valid
  Vertigo O. F. Müller, 1773 -- valid
  Vertigo alabamensis G. H. Clapp, 1915 -- valid -- Alabama vertigo
  Vertigo allyniana S. S. Berry, 1919 -- valid -- small-tooth vertigo
  Vertigo alpestris Alder, 1838 -- valid -- tundra vertigo
  Vertigo andrusiana Pilsbry, 1899 -- valid -- Pacific vertigo
  Vertigo arthuri von Martens, 1882 -- valid
  Vertigo berryi Pilsbry, 1919 -- valid -- ovate california vertigo, rotund vertigo
  Vertigo binneyana Sterki, 1890 -- valid -- cylindrical vertigo
  Vertigo bollesiana (E. S. Morse, 1865) -- valid -- delicate vertigo
  Vertigo clappi Brooks and Hunt, 1936 -- valid -- cupped vertigo
  Vertigo columbiana (Pilsbry and Vanatta, 1900) -- valid -- Columbia vertigo
  Vertigo concinnula Cockerell, 1897 -- valid -- mitered vertigo
  Vertigo conecuhensis G. H. Clapp, 1915 -- valid -- Conecuh vertigo
  Vertigo dalliana Sterki, 1890 -- valid -- horseshoe vertigo
  Vertigo elatior Sterki, 1894 -- valid -- tapered vertigo
  Vertigo gouldi (A. Binney, 1843) -- valid -- variable vertigo
  Vertigo hebardi Vanatta, 1912 -- valid -- Keys vertigo
  Vertigo hinkleyi Pilsbry, 1921 -- valid -- heart vertigo
  Vertigo idahoensis Pilsbry, 1934 -- valid -- Idaho vertigo
  Vertigo meramecensis Van Devender, 1979 -- valid -- bluff vertigo
  Vertigo milium (Gould, 1840) -- valid -- blade vertigo
  Vertigo modesta (Say, 1824) -- valid -- cross vertigo
  Vertigo morsei Sterki, 1894 -- valid -- six-whorl vertigo
  Vertigo nylanderi Sterki, 1909 -- valid -- deep-throat vertigo
  Vertigo occidentalis Sterki, 1907 -- valid -- cone cross vertigo, cone vertigo
  Vertigo oralis Sterki, 1898 -- valid -- palmetto vertigo
  Vertigo oscariana Sterki, 1890 -- valid -- capital vertigo
  Vertigo ovata Say, 1822 -- valid -- ovate vertigo
  Vertigo paradoxa Sterki, 1900 -- valid
  Vertigo parvula Sterki, 1890 -- valid -- smallmouth vertigo
  Vertigo perryi Sterki, 1905 -- valid -- olive vertigo
  Vertigo pygmaea (Draparnaud, 1801) -- valid -- crested vertigo
  Vertigo rugosula Sterki, 1890 -- valid -- striate vertigo
  Vertigo sterkii Pilsbry, 1919 -- valid -- chestnut vertigo
  Vertigo teskeyae Hubricht, 1961 -- valid -- swamp vertigo
  Vertigo tridentata Wolf, 1870 -- valid -- honey vertigo
  Vertigo ventricosa (E. S. Morse, 1865) -- valid -- five-tooth vertigo
  Vertigo wheeleri Pilsbry, 1928 -- valid -- Monte Sano vertigo
  Vesicomya Dall, 1886 -- valid
  Vesicomya vesica (Dall, 1886) -- valid -- fat vesicomya
  Vesicomyidae Dall and Simpson, 1901 -- valid
  Vespericola Pilsbry, 1939 -- valid
  Vespericola armiger (Ancey, 1881) -- valid -- Santa Cruz hesperian
  Vespericola columbianus (I. Lea, 1838) -- valid -- northwest hesperian
  Vespericola eritrichius (S. S. Berry, 1939) -- valid -- velvet hesperian
  Vespericola haplus (S. S. Berry, 1933) -- valid -- Butte Creek hesperian
  Vespericola karokorum Talmadge, 1962 -- valid -- Karok hesperian
  Vespericola klamathicus Roth and W. B. Miller, 1995 -- valid -- Klamath hesperian
  Vespericola marinensis Roth and W. B. Miller, 1993 -- valid -- Marin hesperian
  Vespericola megasoma (Pilsbry, 1928) -- valid -- redwood hesperian
  Vespericola orius (S. S. Berry, 1933) -- valid -- El Dorado hesperian
  Vespericola pilosus (J. Henderson, 1928) -- valid -- brushfield hesperian
  Vespericola pinicola (S. S. Berry, 1916) -- valid -- Monterey hesperian
  Vespericola pressleyi Roth, 1985 -- valid -- Big Bar hesperian
  Vespericola rothi Cordero and W. B. Miller, 1995 -- valid -- Ellery Creek hesperian
  Vespericola scotti Cordero and W. B. Miller, 1995 -- valid -- Benson Gulch hesperian
  Vespericola shasta (S. S. Berry, 1921) -- valid -- Shasta hesperian
  Vespericola sierranus (S. S. Berry, 1921) -- valid -- Siskiyou hesperian
  Vexillum Roding, 1798 -- valid
  Vexillum dermestinum (Lamarck, 1811) -- valid -- mottled miter
  Vexillum epiphaneum (Rehder, 1943) -- valid -- half-brown miter
  Vexillum exiguum (C. B. Adams, 1845) -- valid
  Vexillum gemmatum (G. B. Sowerby II, 1874) -- valid -- gem miter
  Vexillum hendersoni (Dall, 1927) -- valid
  Vexillum histrio (Reeve, 1844) -- valid -- harlequin miter
  Vexillum laterculatum (G. B. Sowerby II, 1874) -- valid -- honeycomb miter
  Vexillum puella (Reeve, 1845) -- valid -- white-spot miter
  Vexillum pulchellum (Reeve, 1844) -- valid -- beautiful miter
  Vexillum styria (Dall, 1889) -- valid -- dwarf deepsea miter
  Vexillum sykesi (Melvill, 1925) -- valid -- white-band miter
  Vexillum trophonium (Dall, 1889) -- valid
  Vexillum wandoense (Holmes, 1860) -- valid -- waxy miter
  Vexillum zythochroa (Melvill, 1888) -- valid
  Vilasina Bartsch, 1960 -- valid
  Vilasina seminuda (Dall, 1897) -- valid -- partly-sculptured crenella
  Vilasina vernicosa (Middendorff, 1849) -- valid -- varnished mussel
  Villosa Frierson, 1927 -- valid
  Villosa amygdala (Lea, 1843) -- valid -- Florida rainbow
  Villosa arkansasensis (Lea, 1862) -- invalid -- Ouachita creekshell
  Villosa choctawensis Athearn, 1964 -- invalid -- Choctaw bean
  Villosa constricta (Conrad, 1838) -- invalid -- notched rainbow
  Villosa delumbis (Conrad, 1834) -- valid -- eastern creekshell
  Villosa fabalis (Lea, 1831) -- invalid -- rayed bean
  Villosa iris (Lea, 1829) -- invalid -- rainbow
  Villosa lienosa (Conrad, 1834) -- invalid -- little spectacle case, little spectaclecase
  Villosa nebulosa (Conrad, 1834) -- invalid -- Alabama rainbow
  Villosa ortmanni (Walker, 1925) -- invalid -- Kentucky creekshell
  Villosa perpurpurea (Lea, 1861) -- invalid -- purple bean
  Villosa taeniata (Conrad, 1834) -- invalid -- painted creekshell
  Villosa trabalis (Conrad, 1834) -- invalid -- Cumberland bean
  Villosa vanuxemensis (Lea, 1838) -- invalid -- mountain creekshell
  Villosa vanuxemensis umbrans (Lea, 1857) -- invalid -- Coosa creekshell
  Villosa vanuxemensis vanuxemensis (Lea, 1838) -- invalid -- mountain creekshell
  Villosa vaughaniana (Lea, 1838) -- invalid -- Carolina creekshell
  Villosa vibex (Conrad, 1834) -- valid -- southern rainbow
  Villosa villosa (B. H. Wright, 1898) -- valid -- downy rainbow
  Viridrillia Bartsch, 1943 -- valid
  Viridrillia cervina Bartsch, 1943 -- valid
  Viridrillia hendersoni Bartsch, 1943 -- valid
  Viridrillia williami Bartsch, 1943 -- valid
  Vitrea Fitzinger, 1833 -- valid
  Vitrea contracta (Westerlund, 1871) -- valid -- contracted glass-snail
  Vitreolina di Monterosato, 1884 -- valid
  Vitreolina arcuata (C. B. Adams, 1850) -- valid -- twisted eulima
  Vitreolina columbiana (Bartsch, 1917) -- valid
  Vitreolina macra (Bartsch, 1917) -- valid
  Vitreolina yod (Carpenter, 1857) -- valid
  Vitricythara Fargo, 1953 -- valid
  Vitricythara metria (Dall, 1903) -- valid
  Vitrina Draparnaud, 1801 -- valid
  Vitrina angelicae Beck, 1837 -- valid -- eastern glass-snail
  Vitrina pellucida (Muller, 1774) -- valid -- western glass-snail
  Vitrinella C. B. Adams, 1850 -- valid
  Vitrinella berryi Bartsch, 1907 -- valid
  Vitrinella columbiana Bartsch, 1921 -- valid
  Vitrinella diaphana (d'Orbigny, 1842) -- valid
  Vitrinella eshnaurae Bartsch, 1907 -- valid
  Vitrinella filifera Pilsbry and McGinty, 1946 -- valid -- threaded vitrinella
  Vitrinella floridana Pilsbry and McGinty, 1946 -- valid -- Florida vitrinella
  Vitrinella helicoidea C. B. Adams, 1850 -- valid -- helix vitrinella
  Vitrinella hemphilli Vanatta, 1913 -- valid
  Vitrinella oldroydi Bartsch, 1907 -- valid
  Vitrinella smithi Bartsch, 1927 -- valid
  Vitrinella stearnsi Bartsch, 1907 -- valid
  Vitrinella tryoni Bush, 1897 -- valid
  Vitrinella williamsoni Dall, 1892 -- valid
  Vitrinellidae Bush, 1897 -- invalid
  Vitrinidae Fitzinger, 1833 -- valid
  Vitrinizonites W. G. Binney, 1879 -- valid
  Vitrinizonites latissimus (J. Lewis, 1875) -- valid -- glassy grapeskin
  Vitrinorbis Pilsbry and Olsson, 1952 -- valid
  Vitrinorbis diegensis (Bartsch, 1907) -- valid -- San Diego vitrinella
  Vitrizonites W. G. Binney, 1879 -- invalid
  Vitrizonites latissimus (J. Lewis, 1875) -- invalid -- glassy grapeskin
  Viviparidae Gray, 1847 -- valid
  Viviparus Montfort, 1810 -- valid
  Viviparus georgianus (Lea, 1834) -- valid -- Banded Mysterysnail
  Viviparus goodrichi Archer, 1933 -- valid -- Globose Mysterysnail
  Viviparus intertextus (Say, 1829) -- valid -- Rotund Mysterysnail
  Viviparus limi Pilsbry, 1918 -- valid -- Ochlockonee Mysterysnail
  Viviparus subpurpureus (Say, 1829) -- valid -- Olive Mysterysnail
  Volutharpa P. Fischer, 1856 -- valid
  Volutidae Rafinesque, 1815 -- valid
  Volutomitra H. Adams and A. Adams, 1853 -- valid
  Volutomitra alaskana Dall, 1902 -- valid
  Volutomitra groenlandica (Moller, 1842) -- valid -- false Greenland miter
  Volutomitridae Gray, 1854 -- valid
  Volutopsion Habe and Ito, 1965 -- valid
  Volutopsion castaneum (Dall, 1877) -- valid -- chestnut whelk
  Volutopsius Morch, 1857 -- valid
  Volutopsius attenuatus (Dall, 1874) -- invalid -- elongate whelk
  Volutopsius callorhinus (Dall, 1877) -- invalid
  Volutopsius callorhinus callorhinus (Dall, 1877) -- invalid -- strombiform whelk
  Volutopsius castanea (Morch, 1858) -- valid -- volute whelk
  Volutopsius castaneus (Morch, 1858) -- invalid
  Volutopsius deformis (Reeve, 1847) -- invalid -- warped whelk
  Volutopsius filosus Dall, 1919 -- invalid -- threaded whelk
  Volutopsius fragilis (Dall, 1891) -- valid -- fragile whelk
  Volutopsius harpa (Mörch, 1857) -- invalid -- left-handed whelk
  Volutopsius melonis (Dall, 1891) -- invalid
  Volutopsius middendorffii (Dall, 1891) -- valid -- tulip whelk
  Volutopsius norvegicus (Gmelin, 1791) -- invalid -- Norway whelk
  Volutopsius norwegicus (Gmelin, 1791) -- valid -- Norway whelk
  Volutopsius pallidus Tiba, 1973 -- valid
  Volutopsius regularis (Dall, 1873) -- valid -- regular whelk
  Volutopsius rotundus Dall, 1919 -- invalid -- rotund whelk
  Volutopsius simplex Dall, 1907 -- invalid -- simple whelk
  Volutopsius stefanssoni Dall, 1919 -- invalid -- shouldered whelk
  Volutopsius trophonius Dall, 1902 -- valid -- frilled whelk
  Volva Linnaeus, 1758 -- valid
  Volva volva Linnaeus, 1758 -- valid -- lined egg spindle
  Volva volva striata (Lamarck, 1810) -- valid -- lined egg spindle
  Volvarina Hinds, 1844 -- valid
  Volvarina albolineata (d'Orbigny, 1842) -- valid -- white-line marginella
  Volvarina avena (Kiener, 1834) -- valid -- orange-band marginella
  Volvarina avenacea (Deshayes, 1844) -- invalid -- little oat marginella
  Volvarina lactea (Kiener, 1841) -- valid
  Volvarina subtriplicata (d'Orbigny, 1842) -- valid -- three-rib marginella
  Volvarina taeniolata Morch, 1860 -- valid -- California marginella
  Volvarina torticula (Dall, 1881) -- invalid -- knave marginella
  Volvarina veliei (Pilsbry, 1896) -- invalid
  Volvatella Newton, 1891 -- valid
  Volvatella bermudae K. B. Clark, 1982 -- valid
  Volvatellidae Pilsbry, 1895 -- valid
  Volvulella Newton, 1891 -- valid
  Volvulella californica Dall, 1919 -- valid -- California spindle-bubble
  Volvulella cylindrica (Carpenter, 1864) -- valid -- cylindrical spindle-bubble
  Volvulella panamica Dall, 1919 -- valid -- Panamic spindle-bubble
  Volvulella paupercula (Watson, 1883) -- valid -- spineless spindle-bubble
  Volvulella persimilis (Morch, 1875) -- valid -- southern spindle-bubble
  Volvulella recta (Morch, 1875) -- valid -- spined spindle-bubble
  Volvulella texasiana Harry, 1967 -- valid -- Texas spindle-bubble
  Vorticifex Meek, 1870 -- valid
  Vorticifex effusa (Lea, 1856) -- valid -- Artemesian Rams-horn, Artemesian Ramshorn
  Vorticifex solida (Dall, 1870) -- valid
  Webbhelix Emberton, 1988 -- valid
  Webbhelix chadwicki (Ferriss, 1907) -- valid -- Kaw whitelip
  Webbhelix multilineata (Say, 1821) -- valid -- striped whitelip
  Williamia Monterosato, 1884 -- valid
  Williamia krebsii (Morch, 1877) -- valid
  Williamia peltoides (Carpenter, 1864) -- valid -- shield false limpet
  Woodbridgea S. S. Berry, 1953 -- valid
  Woodbridgea polystrigma (Dall, 1908) -- valid -- furrowed paper-bubble, furrowed paperbubble
  Xanthonychidae Strebel and Pfeffer, 1879 -- valid
  Xenophora caribaea Petit de la Saussaye, 1857 -- valid -- Caribbean carriersnail
  Xenophora conchyliophora (Born, 1780) -- valid -- American carriersnail
  Xenophora longleyi Bartsch, 1931 -- valid -- shingled carriersnail
  Xenophoridae Philippi, 1853 -- invalid
  Xerarionta Pilsbry, 1913 -- valid
  Xerarionta intercisa (W. G. Binney, 1857) -- valid -- plain cactussnail
  Xerarionta kellettii (Forbes, 1850) -- valid -- Catalina cactussnail
  Xerarionta redimita (W. G. Binney, 1858) -- valid -- wreathed cactussnail
  Xerarionta stearnsiana (Gabb, 1868) -- valid -- speckled cactussnail
  Xerarionta tryoni (Newcomb, 1864) -- valid -- bicolor cactussnail
  Xolotrema Rafinesque, 1819 -- valid
  Xolotrema caroliniense (I. Lea, 1834) -- valid -- blunt wedge
  Xolotrema denotatum (Ferussac, 1821) -- valid -- velvet wedge
  Xolotrema fosteri (F. C. Baker, 1921) -- valid -- bladetooth wedge
  Xolotrema obstrictum (Say, 1821) -- valid -- sharp wedge
  Xolotrema occidentale (Pilsbry and Ferriss, 1907) -- valid -- Arkansas wedge
  Xylophaga Turton, 1822 -- valid
  Xylophaga atlantica Richards, 1942 -- valid -- Atlantic woodeater
  Xylophaga washingtona Bartsch, 1921 -- valid -- Washington woodeater
  Yoldia Moller, 1842 -- valid
  Yoldia cooperii Gabb, 1865 -- valid -- Cooper yoldia
  Yoldia hyperborea (Gould, 1841) -- valid -- northern yoldia
  Yoldia limatula (Say, 1831) -- valid -- file yoldia
  Yoldia myalis (Couthouy, 1838) -- valid -- oval yoldia
  Yoldia sapotilla (Gould, 1841) -- valid -- short yoldia
  Yoldia seminuda Dall, 1871 -- valid -- halfsmooth yoldia, oblique-lined yoldia
  Yoldia thraciaeformis (Storer, 1838) -- invalid -- broad yoldia
  Yoldiella A. E. Verrill and Bush, 1897 -- valid
  Yoldiella dissimilis (A. E. Verrill and Bush, 1898) -- valid -- different yoldia
  Yoldiella frigida (Torell, 1859) -- valid -- frigid yoldia
  Yoldiella inconspicua (A. E. Verrill and Bush, 1898) -- valid -- inconspicuous yoldia
  Yoldiella lucida (Loven, 1846) -- valid -- iridescent yoldia
  Yoldiella nana (M. Sars, 1865) -- valid -- sibling yoldia
  Yoldiella orcia (Dall, 1916) -- valid -- California yoldia
  Zachrysia Pilsbry, 1894 -- valid
  Zachrysia auricoma (Ferussac, 1821) -- valid -- golden zachrysia
  Zachrysia provisoria (Pfeiffer, 1858) -- valid -- cuba garden zachrysia, garden zachrysia
  Zacoleus Pilsbry, 1903 -- valid
  Zacoleus idahoensis Pilsbry, 1903 -- valid -- idaho sheathed slug, sheathed slug
  Zafrona Iredale, 1916 -- valid
  Zafrona idalina (Duclos, 1840) -- valid
  Zafrona pulchella (de Blainville, 1829) -- valid -- beautiful dovesnail
  Zafrona taylorae Petuch, 1987 -- valid
  Zebina H. Adams and A. Adams, 1854 -- valid
  Zebina browniana (d'Orbigny, 1842) -- valid -- smooth risso
  Zebina laevigata (C. B. Adams, 1850) -- valid
  Zirfaea Gray, 1842 -- valid
  Zirfaea crispata (Linnaeus, 1758) -- valid -- atlantic great piddock, great piddock
  Zirfaea pilsbryi Lowe, 1931 -- valid -- Pilsbry piddock
  Zonaria Jousseaume, 1884 -- valid
  Zonaria spadicea (Swainson, 1823) -- valid -- chestnut cowrie
  Zonites Montfort, 1810 -- valid
  Zonites diegoensis Hemphill, 1892 -- valid
  Zonitidae Mörch, 1864 -- valid
  Zonitoides Lehmann, 1862 -- valid
  Zonitoides arboreus (Say, 1816) -- valid -- quick gloss
  Zonitoides elliotti (Redfield, 1856) -- valid -- green dome
  Zonitoides kirbyi R. W. Fullington, 1974 -- valid -- shadow gloss
  Zonitoides lateumbilicatus (Pilsbry, 1895) -- valid -- striate gloss
  Zonitoides limatulus (A. Binney, 1840) -- valid -- dull gloss
  Zonitoides nitidus (Muller, 1774) -- valid -- black gloss
  Zonitoides patuloides (Pilsbry, 1895) -- valid -- Appalachian gloss
  Zonulispira Bartsch, 1950 -- valid
  Zonulispira sanibelensis (Bartsch and Rehder, 1939) -- valid
  Zoogenetes E. S. Morse, 1864 -- valid
  Zoogenetes harpa (Say, 1824) -- valid -- boreal top
   

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