Mitrella aquitanica (FOSSIL) (M.A. Peyrot, 1925 †)
Mitrella aranciicoloris D. Monsecour & D. Monsecour,2011
Arayina arayana (FOSSIL) (Gibson-Smith, 1974 †)
Mitrella arcta K. Monsecour & D. Monsecour,2016
Pyreneola arcuata (W.H. Turton, 1932)
Aesopus arestus W.H. Dall, 1919
Cotonopsis argentea R.S. Houbrick, 1983
Columbella aricia P.L. Duclos, 1846
Mitrella asema (FOSSIL) Gardner, 1937 †
Columbella asopis P.L. Duclos, 1846
Pardalinops aspersa (G.B. II Sowerby, 1844)
Columbella asphaltoda (FOSSIL) C.J. Maury, 1912 †
Columbellopsis astensis (FOSSIL) (L.M.D. Bellardi, 1890 †)
Mitrella astolensis (J.C. Melvill & R. Standen,1901)
Astyris atacamensis Araya,Catalán & Aliaga, 2016
Nassarina atella H.A. Pilsbry & H.N. Lowe,1932
Anachis atkinsoni (J.E. Tenison-Woods,1876)
Anachis atramentaria (G.B. II Sowerby, 1844)
Zafra atrata (A.A. Gould, 1860)
Zemitrella attenuata A.W.B. Powell, 1940
Anachis aurantia (J.B.P.A. Lamarck, 1822)
Alia aurantiaca (W.H. Dall, 1871)
Costoanachis aurea Lussi, 2017
Columbella aureomexicana (F.B. Howard, 1963)
Zafra australensis K. Monsecour & D. Monsecour,2015
Aesopus australis (G.F. Angas, 1877)
Mitrella australis (J.S. Gaskoin, 1851)
Mitrella austrina (J.S. Gaskoin, 1851)
Costoanachis avara (T. Say, 1822)
Anachis avaroides F. Nordsieck, 1975
Mitrella avena (L.A. Reeve, 1859)
Columbella azima P.L. Duclos, 1846
Mitrella azpilicuetai E. Rolán, 2004
Zafrona azteci K. Monsecour & D. Monsecour,2016
Anachis babylonica J.T. Kuroda & T. Habe,1961