Achatina crenatus Swainson, 1821 accepted as Liguus crenatus (Swainson, 1821) accepted as Liguus fasciatus crenatus (Swainson, 1821) (basis of record)
Achatina gracillima L. Pfeiffer, 1839 accepted as Melaniella gracillima (L. Pfeiffer, 1839) (basis of record)
Achatina marginata Swainson, 1821 accepted as Archachatina marginata (Swainson, 1821) (basis of record)
Achatina picta Reeve, 1842 accepted as Liguus fasciatus (O. F. Müller, 1774) (basis of record)
Achatina solida Say, 1825 accepted as Liguus fasciatus (O. F. Müller, 1774) (basis of record)
Achatina texasiana L. Pfeiffer, 1856 accepted as Euglandina texasiana (L. Pfeiffer, 1856) (basis of record)
Agatina fuscata Rafinesque, 1831 accepted as Liguus fasciatus (O. F. Müller, 1774) (basis of record)
Agatina variegata Rafinesque, 1831 accepted as Liguus fasciatus (O. F. Müller, 1774) (basis of record)
Aglaja fidelis (J. E. Gray, 1834) accepted as Monadenia fidelis (J. E. Gray, 1834) (basis of record)
Aglaja fidelis var. flavus Hemphill, 1892 accepted as Monadenia fidelis flava (Hemphill, 1892) (basis of record)
Aglaja fidelis var. minor W. G. Binney, 1885 accepted as Monadenia fidelis minor (W. G. Binney, 1885) (basis of record)
Aglaja fidelis var. subcarinata Hemphill, 1892 accepted as Monadenia subcarinata (Hemphill, 1892) (basis of record)
Agriolimax berendti (Strebel & Pfeffer, 1880) accepted as Deroceras laeve (O. F. Müller, 1774) (basis of record)
Agriolimax berendti var. pictus T. D. A. Cockerell, 1897 accepted as Deroceras laeve (O. F. Müller, 1774) (basis of record)
Agriolimax campestris (A. Binney, 1842) accepted as Deroceras laeve (O. F. Müller, 1774) (basis of record)
Agriolimax campestris var. plumbeus Sterki, 1907 accepted as Deroceras laeve (O. F. Müller, 1774) (basis of record)
Agriolimax campestris var. zonatipes T. D. A. Cockerell, 1892 accepted as Deroceras laeve (O. F. Müller, 1774) (basis of record)
Agriolimax hemphilli ashmuni Pilsbry & Vanatta, 1910 accepted as Deroceras laeve (O. F. Müller, 1774) (basis of record)
Agriolimax laevis (O. F. Müller, 1774) accepted as Deroceras laeve (O. F. Müller, 1774) (basis of record)
Agriolimax laevis campestris (A. Binney, 1842) accepted as Deroceras laeve (O. F. Müller, 1774) (basis of record)
Agriolimax laevis campestris f. nigrescens T. D. A. Cockerell, 1893 accepted as Deroceras laeve (O. F. Müller, 1774) (basis of record)
Agriolimax montanus (Ingersoll, 1875) accepted as Deroceras laeve (O. F. Müller, 1774) (basis of record)
Agriolimax montanus f. intermedius T. D. A. Cockerell, 1888 accepted as Deroceras laeve (O. F. Müller, 1774) (basis of record)
Agriolimax montanus f. tristis T. D. A. Cockerell, 1888 accepted as Deroceras laeve (O. F. Müller, 1774) (basis of record)
Agriolimax montanus f. typicus T. D. A. Cockerell, 1888 accepted as Deroceras laeve (O. F. Müller, 1774) (basis of record)
Agriolimax panormitanus Lessona & Pollonera, 1882 accepted as Deroceras panormitanum (Lessona & Pollonera, 1882) (basis of record)
Alcadia striata (Lamarck, 1822) accepted as Helicina striata Lamarck, 1822 (basis of record)
Allogona (Dysmedoma) townsendiana (I. Lea, 1838) represented as Allogona townsendiana (I. Lea, 1838) (basis of record)
Allogona (Dysmedoma) townsendiana f. frustrationis Pilsbry, 1940 accepted as Allogona townsendiana (I. Lea, 1838) (basis of record)
Allogona lombardii A. G. Smith, 1943 (basis of record)
Allogona profunda var. efasciata B. Walker, 1924 accepted as Allogona profunda (Say, 1821) (basis of record)
Allogona profunda var. strontiana G. H. Clapp, 1916 accepted as Allogona profunda (Say, 1821) (basis of record)
Allogona ptychophora (A. D. Brown, 1870) (basis of record)
Allogona townsendiana (I. Lea, 1838) (basis of record)
Allogona townsendiana var. brunnea (Vanatta, 1924) accepted as Allogona townsendiana (I. Lea, 1838) (basis of record)
Amalia gagates var. plumbea T. D. A. Cockerell, 1891 accepted as Milax gagates (Draparnaud, 1801) (basis of record)
Ammonitella yatesii J. G. Cooper, 1868 (basis of record)
Ammonitella yatesii alleni E. P. Chace, 1951 accepted as Ammonitella yatesii allyni E. P. Chace, 1951 (basis of record)
Ammonitella yatesii allyni E. P. Chace, 1951 (basis of record)
Ammonitella yatesii praecursor Stearns, 1900 † accepted as Ammonitella lunata (Conrad, 1871) † (basis of record)
Ammonitella yatesii yatesii J. G. Cooper, 1868 (basis of record)
Amnicola (Amnicola) floridana Frauenfeld, 1863 accepted as Floridobia floridana (Frauenfeld, 1863) (basis of record)
Amnicola (Amnicola) floridana convexior Wenz, 1924 accepted as Floridobia floridana (Frauenfeld, 1863) (basis of record)
Amnicola (Lyogyrus) Gill, 1863 accepted as Lyogyrus Gill, 1863 (basis of record)
Amnicola (Lyogyrus) retromargo F. G. Thompson, 1968 accepted as Lyogyrus retromargo (F. G. Thompson, 1968) (basis of record)
Amnicola aldrichi insolita Hubricht, 1940 accepted as Fontigens aldrichi (Call & Beecher, 1886) (basis of record)
Amnicola attenuata Haldeman, 1842 accepted as Fontigens nickliniana (I. Lea, 1838) (basis of record)
Amnicola bakeriana Pilsbry, 1917 accepted as Lyogyrus bakerianus (Pilsbry, 1917) (basis of record)
Amnicola clarkei Pilsbry, 1917 (basis of record)
Amnicola currierianus I. Lea, 1863 accepted as Somatogyrus currierianus (I. Lea, 1863) (basis of record)
Amnicola decisa Haldeman, 1845 accepted as Amnicola decisus Haldeman, 1845 (basis of record)
Amnicola forsythi Pilsbry, 1930 accepted as Littoridinops monroensis (Frauenfeld, 1863) (basis of record)
Amnicola greenensis F. C. Baker, 1928 accepted as Marstonia lustrica (Pilsbry, 1890) (basis of record)
Amnicola harperi Dall, 1910 accepted as Pseudotryonia brevissima (Pilsbry, 1890) (basis of record)
Amnicola hendersoni Pilsbry, 1933 accepted as Pyrgulopsis robusta (B. Walker, 1908) (basis of record)
Amnicola idahoensis Pilsbry, 1933 accepted as Pyrgulopsis robusta (B. Walker, 1908) (basis of record)
Amnicola johnsoni Pilsbry, 1899 accepted as Amnicola dalli (Pilsbry & Beecher, 1892) (basis of record)
Amnicola judayi F. C. Baker, 1922 accepted as Cincinnatia integra (Say, 1821) (basis of record)
Amnicola limosa var. superiorensis F. C. Baker, 1928 accepted as Amnicola limosus (Say, 1817) (basis of record)
Amnicola lustrica var. decepta F. C. Baker, 1928 accepted as Marstonia lustrica (Pilsbry, 1890) (basis of record)
Amnicola lustrica var. gelida F. C. Baker, 1921 accepted as Marstonia lustrica (Pilsbry, 1890) (basis of record)
Amnicola lustrica var. perlustrica F. C. Baker, 1928 accepted as Marstonia lustrica (Pilsbry, 1890) (basis of record)
Amnicola missouriensis Pilsbry, 1898 accepted as Fontigens aldrichi (Call & Beecher, 1886) (basis of record)
Amnicola oneida Pilsbry, 1917 accepted as Marstonia lustrica (Pilsbry, 1890) (basis of record)
Amnicola oscitans Pilsbry, 1930 accepted as Littoridinops monroensis (Frauenfeld, 1863) (basis of record)
Amnicola pallida Haldeman, 1842 accepted as Amnicola limosus (Say, 1817) (basis of record)
Amnicola parva I. Lea, 1841 accepted as Amnicola limosus (Say, 1817) (basis of record)
Amnicola peracuta Pilsbry & B. Walker, 1889 accepted as Cincinnatia integra (Say, 1821) (basis of record)
Amnicola pilsbryana J. L. Baily & R. I. Baily, 1952 accepted as Pyrgulopsis pilsbryana (J. L. Baily & R. I. Baily, 1952) (basis of record)
Amnicola pilsbryi B. Walker, 1906 accepted as Lyogyrus pilsbryi (B. Walker, 1906) (basis of record)
Amnicola pilsbryi J. L. Baily & R. I. Baily, 1951 accepted as Pyrgulopsis pilsbryana (J. L. Baily & R. I. Baily, 1952) (basis of record)
Amnicola precursor F. C. Baker, 1928 accepted as Lyogyrus walkeri (Pilsbry, 1898) (basis of record)
Amnicola pumilus Conrad, 1834 accepted as Somatogyrus pumilus (Conrad, 1834) (basis of record)
Amnicola sablensis Pilsbry, 1951 accepted as Littoridinops monroensis (Frauenfeld, 1863) (basis of record)
Amnicola scarboroughi Tryon, 1870 accepted as Cincinnatia integra (Say, 1821) (basis of record)
Amnicola schrokingeri Frauenfeld, 1863 accepted as Amnicola limosus (Say, 1817) (basis of record)
Amnicola stygia Hubricht, 1971 accepted as Amnicola stygius Hubricht, 1971 (basis of record)
Amnicola walkeri Pilsbry, 1898 accepted as Lyogyrus walkeri (Pilsbry, 1898) (basis of record)
Amnicola walkeri var. foxensis F. C. Baker, 1928 accepted as Lyogyrus walkeri (Pilsbry, 1898) (basis of record)
Amnicola winkleyi var. leightoni F. C. Baker, 1920 † accepted as Marstonia lustrica (Pilsbry, 1890) (basis of record)
Ampullaria miamiensis Pilsbry, 1899 accepted as Pomacea paludosa (Say, 1829) (basis of record)
Ampullaria pinei Dall, 1898 accepted as Pomacea paludosa (Say, 1829) (basis of record)
Anadenulus cockerelli (Hemphill, 1890) (basis of record)
Anadenus cockerelli Hemphill, 1890 accepted as Anadenulus cockerelli (Hemphill, 1890) (basis of record)
Ancotrema hybridum (Ancey, 1888) accepted as Ancotrema sportella (A. Gould, 1846) (basis of record)
Ancotrema sportella (A. Gould, 1846) (basis of record)
Ancotrema sportella sinkyonum B. Roth, 1990 (basis of record)
Ancotrema sportella sportella (A. Gould, 1846) (basis of record)
Ancotrema voyanum (Newcomb, 1865) (basis of record)
Ancotrema voyanum humboldtense Pilsbry, 1946 (basis of record)
Ancotrema voyanum voyanum (Newcomb, 1865) (basis of record)
Ancotrema zopherum B. Roth, 1990 (basis of record)
Anculosa (Lithasia) Haldeman, 1840 accepted as Lithasia Haldeman, 1840 (basis of record)
Anculosa (Lithasia) geniculata Haldeman, 1840 accepted as Lithasia geniculata (Haldeman, 1840) (basis of record)
Anculosa (Mudalia) affinis Haldeman, 1841 accepted as Leptoxis dilatata (Conrad, 1835) (basis of record)
Anculosa (Mudalia) turdiga Haldeman, 1840 accepted as Elimia melanoides (Conrad, 1834) (basis of record)
Anculosa fusca var. minor Stearns, 1893 accepted as Pyrgulopsis erythropoma (Pilsbry, 1899) (basis of record)
Ancylus (Ferrissia) hendersoni B. Walker, 1908 accepted as Ferrissia fragilis (Tryon, 1863) accepted as Ferrissia californica (Rowell, 1863) (basis of record)
Ancylus (Ferrissia) hinkleyi B. Walker, 1908 accepted as Rhodacmea hinkleyi (B. Walker, 1908) (basis of record)
Ancylus (Ferrissia) novangliae B. Walker, 1908 accepted as Ferrissia fragilis (Tryon, 1863) accepted as Ferrissia californica (Rowell, 1863) (basis of record)