Cancellaria ancycla (FOSSIL) J. Gardner, 1937 †
Trigonostoma andaluciensis (FOSSIL) B.M. Landau, 1984 †
Scalptia androyensis A. Verhecken & L. Bozzetti,2006
Tribia angasi (J.C.H. Crosse, 1863)
Tritonoharpa angasi (J.W. Brazier, 1877)
Hertleinia angosturana (FOSSIL) E.S. Marks, 1949 †
Unitas angulifera (FOSSIL) (G.P. Deshayes, 1864 †)
Plesiotriton angustus (FOSSIL) (A. Watelet, 1851 †)
Brocchinia anomala (FOSSIL) (P. Marshall& R. Murdoch, 1920 †)
Cancellaria anomoia (FOSSIL) W.P. Woodring, 1970 †
Tritonoharpa ansonae A.G. Beu & P.A. Maxwell,1987
Nothoadmete antarctica (H. Strebel, 1908)
Tritonoharpa antiquata (R.B. Hinds in L.A. Reeve,1844)
Trigonostoma antiquatum (R.B. Hinds, 1843)
Sydaphera anxifer (T. Iredale, 1925)
Trigonostoma apertum (FOSSIL) (A.H.E. Beyrich, 1856 †)
Aphera aphrodite (FOSSIL) B.M. Landau & al., 2012 †
Cancellaria apimela (FOSSIL) W.P. Woodring, 1970 †
Zeadmete apoensis A. Verhecken, 2011
Merica aqualica (R.E. Petit& M.G. Harasewych, 1986)
Tritonoharpa aquitaniensis (FOSSIL) Lesport, Cluzaud& A. Verhecken, 2015 †
Zeadmete araeostyla (FOSSIL) (P.A. Maxwell, 1988 †)
Mirandaphera arafurensis (A. Verhecken, 1997)
Nipponaphera argo P. Bouchet & R.E. Petit,2008
Scalptia articularis (G.B. I Sowerby, 1832)
Scalptia articularoides A. Verhecken, 1995
Marianarona asheri (FOSSIL) E.J. Petuch, 1988 †
Merica asperella (J.B.P.A. Lamarck, 1822)
Zeadmete atlantica R.E. Petit, L.D. Campbell& S.C. Campbell, 2010
Admetula atopodonta (R.E. Petit& M.G. Harasewych, 1986)
Narona atraktoides (FOSSIL) (J. Gardner, 1937 †)
Plesiotriton aucoini (FOSSIL) Lesport, Cluzaud& A. Verhecken, 2015 †
Zeadmete aupouria A.W.B. Powell, 1940
Pyruclia auriculaperta (FOSSIL) E.H. Vokes, 1938 †
Sydaphera australis (G.B. I Sowerby, 1832)