Alvania aartseni A. Verduin, 1986
Crisilla aartseni (A. Verduin, 1984)
Rissoa aartseni A. Verduin, 1985
Rissoa abbreviata (FOSSIL) A.A. Baudon, 1853 †
Setia abjecta (R.B. Watson, 1873)
Alvania abrupta (R.K. Dell, 1956)
Alvania abstersa J. van der Linden& J.J. Van Aartsen, 1994
Ihungia acantha (FOSSIL) J. Marwick, 1965 †
Rissoa acicula (A. Risso, 1826)
Onoba aculeus (Gould, 1841)
Rissoa acuticosta (FOSSIL) A. von Koenen, 1892 †
Turboella acuticosta (FOSSIL) F. Sacco, 1895 †
Benthonellania acuticostata (W.H. Dall, 1889)
Ovirissoa adarensis (E.A. Smith, 1902)
Rissoa adela (FOSSIL) d'Orbigny, 1852 †
Alvania adiaphoros P. Bouchet & A. Warén,1993
Alvania adinogramma P. Bouchet & A. Warén,1993
Attenuata admiranda (FOSSIL) Richardson, 1997 †
Onoba aedicula (FOSSIL) (C.R. Laws, 1940 †)
Onoba aedonis (R.B. Watson, 1886)
Alvania aeoliae S. Palazzi, 1988
Cingula aequa (E.A. Smith, 1890)
Ihungia aequalis (FOSSIL) C.R. Laws, 1941 †
Alvania aequisculpta (J. Keep, 1887)
Attenuata affinis (A.W.B. Powell, 1940)
Alvania africana S. Gofas, 1999
Haurakia africana (K.H.J. Thiele, 1925)
Cingula agapeta (E.A. Smith, 1890)
Benthonellania agastachys P. Bouchet & A. Warén,1993
Alvania aglaja (FOSSIL) C. De Stefani& D. Pantanelli, 1888 †
Onoba agnewi (J.E. Tenison-Woods,1877)
Cingula agulhasensis K.H.J. Thiele, 1925
Onoba ainsworthi C. Hedley, 1916
Alvania akibai (M. Yokoyama, 1926)
Setia alaskana (P. Bartsch, 1912)