Dosinia abyssicola T. Habe, 1961
Callista accincta A. Römer, 1864
Dosinia acetabulum (FOSSIL) T.A. Conrad, 1832 †
Dosinia acetabulum blackwelderi (FOSSIL) L.W. Ward, 1992 †
Dosinia acetabulum thori (FOSSIL) L.W. Ward, 1992 †
Macrocallista acuminata (FOSSIL) W.H. Dall, 1903 †
Hinemoana acuminata (FOSSIL) (F.W. Hutton, 1873 †)
Costellipitar acuminatus (G.B. II Sowerby, 1851)
Lamelliconcha acutecostata (FOSSIL) (W.M. Gabb, 1873 †)
Costacallista adabionensis (FOSSIL) (Oppenheim 1915) †
Dosinia adami M. Nicklés, 1955
Protocallithaca adamsi (L.A. Reeve, 1863)
Sunetta adelinae G.F. Angas, 1868
Tapes aenigmaticus (FOSSIL) Fischer & R. Tournouer,1874 †
Lamelliconcha aequicincta (FOSSIL) E.M. Spieker, 1922 †
Macridiscus aequilatera (G.B. I Sowerby, 1825)
Agriopoma aequinoctiale E. Fischer-Piette, 1969
Petricola aequistriata G.B. II Sowerby, 1874
Gafrarium aequivocum (H.S. Holten, 1802)
Costacallista aequorea (FOSSIL) (T.A. Conrad, 1833 †)
Pitar affinis (J.F. Gmelin, 1791)
Dosinia afra (J.F. Gmelin, 1791)
Transennella africana (FOSSIL) Adegoke 1977 †
Antigona aglaurae (FOSSIL) A. Brongniart, 1823 †
Lirophora agraria (FOSSIL) White, 1887 †
Pitar alabastrum (L.A. Reeve, 1863)
Megapitaria albaria (T. Say, 1830)
Pitar albidus (J.F. Gmelin, 1791)
Venus albina G.B. II Sowerby, 1853
Pitar albinus (J.B.P.A. Lamarck, 1818)
Periglypta albocancellata (M. Huber, 2010)
Pitar aldrichi (FOSSIL) D.T. Dockery, 1982 †
Hyphantosoma aletes (L.G. Hertlein& A.M. Strong, 1948)
Gafrarium alfredense (P. Bartsch, 1915)
Circomphalus allporti (FOSSIL) J.E. Tenison-Woods,1876 †