Telleria antecedens (FOSSIL) E.A.L. Kittl, 1894 †
Vitreolina antiflexa (T.A. de M. Monterosato,1884)
Eulima antiqua E. Forbes, 1846
Eulima aoteaensis (FOSSIL) P. Marshall & R. Murdoch,1921 †
Hemiaclis aqabaensis K. Bandel, 2005
Hypermastus araeosomae T. Habe, 1992
Melanella archeyi (H.J. Finlay, 1928)
Eulima arcuata G.P. Deshayes, 1850
Vitreolina arcuata (Adams, 1850)
Eulitoma arcus P. Bouchet & A. Warén,1986
Sticteulima ariel (C.B. Adams, 1861)
Melanella arleyi J. Espinosa, J.A. Ortea& J. Magaña, 2001
Ophiolamia armigeri A. Warén & R. Carney,1981
Eulimostraca armonica J. Espinosa & J.A. Ortea,2007
Paramegadenus arrhynchus (A. Ivanov, 1937)
Pictobalcis articulata (G.B. I Sowerby, 1834)
Fusceulima asser (P. Bartsch, 1915)
Cythnia asteriaphila P.P. Carpenter, 1864
Stilifer astericola W.J. Broderip, 1832
Thyca astericola (A. Adams & L.A. Reeve,1850)
Vitreobalcis asteriophila T. Habe, 1989
Echineulima asthenosomae (A. Warén, 1980)
Parvioris astropectenicola (J.T. Kuroda & T. Habe,1950)
Pulicicochlea astropyga W.F. Ponder & R.U. Gooding,1978
Eulimetta atlantica Souza & A. Pimenta, 2015
Melanella atlantica (E.A. Smith, 1890)
Megadenus atrae Takano,Warén & Kano, 2017
Melanella attenuata (G.B. II Sowerby, 1866)
Niso attilioi (C.M. Hertz & C.M. Hertz,1982)
Eulima atypha A.E. Verrill & K.J. Bush,1900
Melanella aucklandica (H.H. Suter, 1909)
Melanella augur (G.F. Angas, 1865)
Eulima augustoi A. Nobre, 1937
Balcis aulaca (FOSSIL) W.P. Woodring, 1970 †
Curveulima aupouria (A.W.B. Powell, 1937)