Cancellaria abnormis J.E. Gray, 1847
Loxotaphrus abnormis (FOSSIL) (J.F. Bayan, 1870 †)
Cancellaria acalypta (FOSSIL) W.P. Woodring, 1970 †
Tritonoharpa aclinica (FOSSIL) (Tucker & R.B. Wilson,1932 †)
Caveola acuta (FOSSIL) (B. Wade, 1926 †)
Trigonostoma acutangulum (FOSSIL) (Faujas, 1817 †)
Trigonostoma acutangulum westziana (J.P.S. Grateloup, 1840)
Cancellaria adelae H.A. Pilsbry, 1940
Africotriton adelphum P. Bouchet & R.E. Petit,2002
Cancellicula aethiopica (K.H.J. Thiele, 1925)
Waipaoa affectata (FOSSIL) J. Marwick, 1931 †
Admetula affluens P. Bouchet & R.E. Petit,2008
Admetula afra R.E. Petit& M.G. Harasewych, 2000
Cancellaria africana R.E. Petit, 1970
Cancellaria agalma J.C. Melvill & R. Standen,1901
Agatrix agassizii (W.H. Dall, 1889)
Nipponaphera agastor P. Bouchet & R.E. Petit,2008
Agatrix agathe (FOSSIL) B.M. Landau, R.E. Petit& F. Da Silva, 2012 †
Narona agria (FOSSIL) W.C. Mansfield, 1930 †
Neadmete ahoi M.G. Harasewych& R.E. Petit, 2011
Euclia alacertata (FOSSIL) B.M. Landau & al., 2012 †
Tritonoharpa alanbeui (FOSSIL) B.M. Landau & al., 2013 †
Iphinopsis alba (P. Bouchet & A. Warén,1985)
Cancellaria albida R.B. Hinds, 1843
Cancellaria aldrichi (FOSSIL) J. Gardner, 1937 †
Scalptia aliguayensis A. Verhecken, 2008
Inglisella allophyla (FOSSIL) P.A. Maxwell, 1988 †
Cancellaria altavillae (FOSSIL) (I. Libassi, 1859 †)
Cancellaria alternata (FOSSIL) T.A. Conrad, 1834 †
Gerdiella alvesi S.F.B. de Lima, J.C.N. Barros& R.E. Petit, 2007
Trigonaphera amakusana R.E. Petit, 1974
Cancellaphera amasia T. Iredale, 1930
Cancellaria amoena (FOSSIL) A.A. Olsson & A. Harbison,1953 †
Inglisella ampla (FOSSIL) C.R. Laws, 1935 †
Cancellaria ampullacera R.P. Lesson, 1841