Bela anna K.H.J. Thiele, 1925
Pyrgocythara annaclaireleeae (E.F. Garcia, 2008)
Bela annemariae P. Lozouet, 2015
Macteola anomala (G.F. Angas, 1877)
Cythara anthera (FOSSIL) J. Gardner, 1937 †
Mangelia anthetika (FOSSIL) J. Gardner, 1937 †
Eucithara antillarum (L.A. Reeve, 1846)
Kurtziella antiochroa (H.A. Pilsbry & H.N. Lowe,1932)
Kurtziella antipyrgus (H.A. Pilsbry & H.N. Lowe,1932)
Benthomangelia antonia (W.H. Dall, 1881)
Bela antwerpiensis (FOSSIL) R. Marquet, 1997 †
Ithycythara apicodenticulata E. Robba, S.I. Di Geronimo, N. Chaimanee& al., 2007
Agathotoma apocrypha (E.F. Garcia, 2008)
Leiocithara apollinea (J.C. Melvill, 1904)
Cryoturris aptera (FOSSIL) W.P. Woodring, 1928 †
Propebela arctica (A. Adams, 1855)
Sorgenfreispira ardovinii (P. Mariottini& M. Oliverio, 2008)
Eucithara arenivaga C. Hedley, 1922
Propebela areta (P. Bartsch, 1941)
Kurtzia arteaga (W.H. Dall & P. Bartsch,1910)
Eucithara articulata (G.B. III Sowerby, 1894)
Bactrocythara asarca (W.H. Dall & C.T. Simpson,1901)
Bactrocythara ascara (FOSSIL) (W.H. Dall& C.T. Simpson, 1900 †)
Guraleus asper C.F. Laseron, 1954
Propebela assimilis (Sars, 1878)
Mangelia asteria (FOSSIL) J. Gardner, 1937 †
Agathotoma asthenika E. Rolán, R. Fernández-Garcés& C. Redfern, 2012
Pyrgocythara astricta (L.A. Reeve, 1846)
Anticlinura atlantica E.F. Garcia, 2005
Bela atlantidea (J. Knudsen, 1952)
Mangelia atonia (W.H. Dall, 1881)
Kurtziella atrostyla (G.W. Tryon, 1884)
Mangelia attenuata (G. Montagu, 1803)
Ithycythara auberiana (A.V.M.D. D'Orbigny,1847)
Euryentmena australiana T. Shuto, 1983