Opalia abbotti W.J. Clench & H. Turner,1952
Epitonium abyssicola (M.M. Schepman, 1909)
Epitonium acanthopleurum (J.C. Verco, 1906)
Epitonium acapulcanum W.H. Dall, 1917
Epitonium actinariophilum (H. Masahito & T. Habe,1976)
Epitonium aculeatum (G.B. II Sowerby, 1844)
Acrilla acuminata (G.B. II Sowerby, 1844)
Crisposcala acuminiensis (FOSSIL) (de Boury, 1883 †)
Cylindriscala acus (R.B. Watson, 1883)
Aciculiscala acuta (FOSSIL) N.F. Sohl, 1963 †
Cirsotrema acuta (FOSSIL) (J. de C. Sowerby,1813 †)
Epifungium adgranulosa E. Gittenberger& A. Gittenberger, 2005
Epifungium adgravis E. Gittenberger& A. Gittenberger, 2005
Epitonium adjunctum (F.P. Jousseaume, 1912)
Epifungium adscabra E. Gittenberger& A. Gittenberger, 2005
Epitonium aequabile (FOSSIL) Kellum, 1926 †
Epitonium aequale (K.H.J. Thiele, 1925)
Cylindriscala aequatorialis (K.H.J. Thiele, 1925)
Acrilla affinis (FOSSIL) G.P. Deshayes, 1861 †
Amaea africana P. Bouchet & S. Tillier,1978
Epitonium agitabile (F.P. Jousseaume, 1912)
Opalia aglaia (P. Bartsch, 1915)
Chuniscala agulhasensis (K.H.J. Thiele, 1925)
Opalia ahiparana (A.W.B. Powell, 1930)
Epitonium aizyense (FOSSIL) G.P. Deshayes, 1861 †
Epitonium alabiforme R.N. Kilburn, 1985
Epitonium alaquaense (FOSSIL) W.C. Mansfield, 1935 †
Epitonium alata (G.B. II Sowerby, 1844)
Opalia alba (M.E.A. de Boury, 1911)
Scalaria albae (FOSSIL) Tate †
Epitonium albidum (A.V.M.D. D'Orbigny,1842)
Epitonium albolineatum (G.B. II Sowerby, 1844)
Cycloscala aldeynzeri E.F. Garcia, 2001
Epitonium algerianum (H.C. Weinkauff, 1866)
Epitonium alidotum (FOSSIL) W.P. Woodring, 1928 †