Laevichlamys allorenti (H.H. Dijkstra, 1988)
Pecten alpha (FOSSIL) W.H. Dall, 1898 †
Chlamys alta (L.A. Reeve, 1853)
Delectopecten alternilineatus (FOSSIL) (Clark, 1918 †)
Chlamys alumensis (FOSSIL) J. Gardner, 1926 †
Antillipecten alumensis (FOSSIL) (W.H. Dall, 1898 †)
Chlamys amandi L.G. Hertlein, 1935
Argopecten ameleus (FOSSIL) W.P. Woodring, 1925 †
Decatopecten amiculum R.A. Philippi, 1851
Semipallium amicum (E.A. Smith, 1885)
Indopecten amusiiformis (FOSSIL) Hudson & Jefferies,1961 †
Euvola amusoides (O. Macsotay & B. Campos,2001)
Nanaochlamys anapleus (FOSSIL) W.P. Woodring, 1946 †
Anatipopecten anatipes (FOSSIL) (Morton, 1833 †)
Laevichlamys andamanica (H.B. Preston, 1908)
Aequipecten andersoni (FOSSIL) R. Arnold, 1906 †
Aequipecten andersoni clemonensis (FOSSIL) Etherington †
Leptopecten andersoni (FOSSIL) (Loel & Corey) †
Austrochlamys anderssoni (Hennig, 1911)
Capedopecten anellus (FOSSIL) Dijkstra & Janssen 1988 †
Mimachlamys angelonii (FOSSIL) (C. De Stefani& D. Pantanelli, 1880 †)
Eopecten anglica (FOSSIL) Arkell, 1931 †
Chlamys angsanana (FOSSIL) Martin, 1922 †
Antillipecten anguillensis (FOSSIL) (R.J.L. Guppy, 1867 †)
Serratovola angusticostata H.H. Dijkstra, 2008
Camptonectes annulatus (FOSSIL) (Sowerby, 1826 †)
Argopecten anteamplicostata (FOSSIL) W.C. Mansfield, 1936 †
Chlamys antiaustralis (FOSSIL) R. Tate, 1886 †
Pecten antiguensis (FOSSIL) J. Brown, 1913 †
Delectopecten antillarum (FOSSIL) P.O. Jung, 1971 †
Antillipecten antillarum (C.A. Récluz, 1853)
Argopecten antonitaensis (FOSSIL) J.W. Durham, 1950 †
Delectopecten arachnoideus (FOSSIL) Sokolov & Bodylevsky 1931 †,
Chlamys arakawai (FOSSIL) S. Nomura, 1935 †
Talochlamys araroaensis (FOSSIL) (A.G. Beu, 1970 †)