Coralliophila aberrans (C.B. Adams, 1850)
Trophonopsis aberrans (R. Houart, 1991)
Ponderia abessensis P. Lozouet, 1998
Ponderia abies R. Houart, 1986
Dicathais abjecta (FOSSIL) (R. Tate, 1888 †)
Coralliophila abnormis (E.A. Smith, 1878)
Favartia absona (FOSSIL) (G.J. De Cristofori& G. Jan, 1832 †)
Trialatella abyssicola (J.C.H. Crosse, 1865)
Pagodula abyssorum (A.E. Verrill, 1885)
Coronium acanthodes (R.B. Watson, 1882)
Ocenebra acanthophora (A. Adams, 1863)
Pterochelus acanthopterus (J.B.P.A. Lamarck, 1816)
Pterochelus acanthopterus saibaiensis (J.C. Melvill & R. Standen,1899)
Typhis acanthopterus (FOSSIL) R. Tate, 1888 †
Murex acanthostephes R.B. Watson, 1883
Litozamia acares R. Houart, 2013
Pagodula acceptans (K.H. Barnard, 1959)
Leptotrophon acerapex (R. Houart, 1986)
Ocinebrina aciculata (J.B.P.A. Lamarck, 1822)
Poirieria actinophora (W.H. Dall, 1889)
Xanthochorus aculeata (FOSSIL) (R. Tate, 1888 †)
Pagodula aculeata (R.B. Watson, 1882)
Thalessa aculeata (G.P. Deshayes, 1844)
Triplex aculeatus (J.B.P.A. Lamarck, 1822)
Typhis aculeatus (FOSSIL) P. Vella, 1961 †
Coralliofusus acus (J.T. Kuroda, 1953)
Typhis acuticosta (FOSSIL) T.A. Conrad, 1830 †
Aspella acuticostata (W.H. Turton, 1932)
Poirieria acuticostata (FOSSIL) Staadt in A.E.M. Cossmann,1913 †
Laevityphis acuticostata (FOSSIL) (T.A. Conrad, 1830 †)
Coralliophila adansoni S. Kosuge & C. Fernández,1989
Chicoreus adelaidensis (FOSSIL) R. Tate, 1888 †
Siratus adelosus (FOSSIL) E.H. Vokes, 1989 †
Favartia adenensis (R. Houart & W. Wranik,1989)
Orania adiastolos R. Houart, 1995