Bostryx abancayensis H.A. Pilsbry, 1944 Peru, Cuzco
Bostryx abancayensis rudistriatus F. Haas, 1955 Peru, Apurimac18 mm
Bulimus abbreviatus J. Gassies, 1871 New Caledonia, Lifou
Plicolumna abbreviatus (J.G. Cooper, 1892) Mexico, Baja California Sur, La Paz22,2 mm
Drymaeus abruptus H. Rolle, 1905 Peru, Huancabamba42,5 mm
Drymaeus abscissus L. Pfeiffer, 1855 Ecuador, Quito27,8 mm
Drymaeus abyssorum (A.V.M.D. D'Orbigny,1835) Bolivia43,7 mm
Bostryx acalles (L. Pfeiffer, 1853) Peru10 mm
Drymaeus acervatus L. Pfeiffer, 1857 Brazil, Sao Paulo32 mm
Naesiotus achatellinus (E. Forbes, 1850) Galapagos19 mm
Scutalus achrous F. Haas, 1952 Bolivia
Bulimus acicularis (FOSSIL) J.B.P.A. Lamarck, 1804 † France, Grignon
Bostryx acme F. Haas, 1955 Peru, Apurimac
Drymaeus acobambensis W.K. Weyrauch, 1967 Peru, Huancavelica30 mm
Bostryx acromelas (P.M.A. Morelet, 1845) Peru, Cuzco19,9 mm
Drymaeus acuminatus S.I. Da Costa, 1906 Brazil, Mato Grosso33,4 mm
Naesiotus adelphus W.H. Dall, 1917 Galapagos
Suniellus adriani A.S.H. Breure, 2011 Ecuador32,5 mm
Bulimulus adserseni (G. Coppois, 1985) Galapagos
Drymaeus aequatorianus E.A. Smith, 1877 Ecuador28,8 mm
Scutalus aequatorius L. Pfeiffer, 1855 Ecuador35,1 mm
Bostryx aequicostata H.A. Rehder, 1945 South America
Mesembrinus aestivus (L. Pfeiffer, 1857) Peru16,9 mm
Lissoacme affinis (W.J. Broderip, 1832) Bolivia27,5 mm
Peronaeus agueroi W.K. Weyrauch, 1960 Peru, Lima
Bostryx aguilari W.K. Weyrauch, 1967 Peru, Lima
Peronaeus aguirrei (A. Doering, 1884) Argentina, Buenos Aires16 mm
Peronaeus aguirrei azulensis (A. Doering, 1884) Argentina, Sierra Baya22 mm
Bostryx aileenae A.S.H. Breure, 1978 Peru, Lima14,9 mm
Naesiotus akamatus (W.H. Dall, 1917) Galapagos
Drymaeus alabastrinus S.I. Da Costa, 1906 Colombia33 mm
Kuschelenia alauda (L.H. Hupé, 1857) Peru30 mm
Kuschelenia alauda hendeensis (H.A. Pilsbry, 1926) Peru, Oroya31 mm
Bostryx alausiensis (A. Cousin, 1887) Ecuador24,3 mm
Naesiotus albemarlensis W.H. Dall, 1917 Galapagos14,5 mm