Cantharus albovarius H.C. Küster, 1862
Falsimohnia albozonata (R.B. Watson, 1886)
Calagrassor aldermenensis (A.W.B. Powell, 1971)
Cominella alertae (R.K. Dell, 1956)
Buccinum aleuticum W.H. Dall, 1895
Japelion aleuticus (W.H. Dall, 1895)
Neptunea alexeyevi K. Fraussen & Y. Terryn,2007
Austrofusus allani (FOSSIL) L. C. King, 1934 †
Austrofusus alpha (FOSSIL) Finlay, 1926 †
Solenosteira alta (FOSSIL) E.J. Petuch, 1994 †
Ptychosalpinx altilis (FOSSIL) (T.A. Conrad, 1832 †)
Neptunea altispira (FOSSIL) W.M. Gabb, 1869 †
Anomalisipho altus (S.V. Wood, 1848)
Lacinia alveata (FOSSIL) T.A. Conrad, 1833 †
Engina alveolata (L.C. Kiener, 1836)
Proneptunea amabilis K.H.J. Thiele, 1912
Neptunea amianta (W.H. Dall, 1890)
Prosipho amiantus P.G. Oliver & G.B. Picken,1984
Euthria amorimi K. Fraussen, 2004
Metula amosi E.G. Vanatta, 1913
Pisania amphodon E.C. Von Martens, 1880
Volutharpa ampullacea (A.T. von Middendorff,1848)
Volutharpa ampullacea limnaeformis T. Habe & K. Itô, 1980
Volutharpa ampullacea nipponkaiensis T. Habe & K. Itô, 1980
Engina anakisia (P.L. Duclos, 1850)
Pollia anconai (FOSSIL) (Malatesta, 1960 †)
Metula andamanica E.A. Smith, 1906
Siphonalia andersoni (FOSSIL) Wagner & Schilling,1923 †
Falsimohnia anderssoni (H. Strebel, 1908)
Pollia andrei (FOSSIL) (B. de Basterot, 1825 †)
Engina androyensis K. Fraussen, E. Monnier& J. Rosado, 2015
Metula anfractura H.R. Matthews& E. de C. Rios, 1968
Trominina angasiana (FOSSIL) (M. Yokoyama, 1932 †)
Metula angioyorum M. Parth, 1992
Chauvetia anglica (FOSSIL) (Wood, 1874 †)