Bostryx abancayensis H.A. Pilsbry, 1944
Bostryx abancayensis rudistriatus F. Haas, 1955
Bulimus abbreviatus J. Gassies, 1871
Plicolumna abbreviatus (J.G. Cooper, 1892)
Drymaeus abruptus H. Rolle, 1905
Drymaeus abscissus L. Pfeiffer, 1855
Drymaeus abyssorum (A.V.M.D. D'Orbigny,1835)
Bostryx acalles (L. Pfeiffer, 1853)
Drymaeus acervatus L. Pfeiffer, 1857
Naesiotus achatellinus (E. Forbes, 1850)
Scutalus achrous F. Haas, 1952
Bulimus acicularis (FOSSIL) J.B.P.A. Lamarck, 1804 †
Bostryx acme F. Haas, 1955
Drymaeus acobambensis W.K. Weyrauch, 1967
Bostryx acromelas (P.M.A. Morelet, 1845)
Drymaeus acuminatus S.I. Da Costa, 1906
Naesiotus adelphus W.H. Dall, 1917
Suniellus adriani A.S.H. Breure, 2011
Bulimulus adserseni (G. Coppois, 1985)
Drymaeus aequatorianus E.A. Smith, 1877
Scutalus aequatorius L. Pfeiffer, 1855
Bostryx aequicostata H.A. Rehder, 1945
Mesembrinus aestivus (L. Pfeiffer, 1857)
Lissoacme affinis (W.J. Broderip, 1832)
Peronaeus agueroi W.K. Weyrauch, 1960
Bostryx aguilari W.K. Weyrauch, 1967
Peronaeus aguirrei (A. Doering, 1884)
Peronaeus aguirrei azulensis (A. Doering, 1884)
Bostryx aileenae A.S.H. Breure, 1978
Naesiotus akamatus (W.H. Dall, 1917)
Drymaeus alabastrinus S.I. Da Costa, 1906
Kuschelenia alauda (L.H. Hupé, 1857)
Kuschelenia alauda hendeensis (H.A. Pilsbry, 1926)
Bostryx alausiensis (A. Cousin, 1887)
Naesiotus albemarlensis W.H. Dall, 1917