Anadara kagoshimensis (S. Tokunaga, 1906)
Arca kannegieteri (FOSSIL) Icke, 1907 †
Arca kauaia (W.H. Dall, P. Bartsch& H.A. Rehder, 1938)
Xenophorarca kauaiensis (W.H. Dall, P. Bartsch& H.A. Rehder, 1938)
Barbatia kayalensis (FOSSIL) A. Dey, 1961 †
Arca kelirensis (FOSSIL) K. Martin, 1916 †
Barbatia kickapooensis (FOSSIL) Garvie, 2013 †
Anadara kiiensis (FOSSIL) A. Mizuno, 1952 †
Anadara kikaizimana S. Nomura & N. Zinbo,1934
Trisidos kiyonoi (J. Makiyama, 1931)
Arca koerti (FOSSIL) Bohm & Weisfermel, 1913 †
Anadara korfiensis (FOSSIL) V.N. Sinelnikova, 1987 †
Arca koumaci K.A. Lutaenko& P. Maestrati, 2007
Barbatia kraussi (C.F.F. von Krauss, 1848)
Barbatia krishtofovichae (FOSSIL) Devjatilova, 1981 †
Anadara kroensis (FOSSIL) Boettger, 1883 †
Samacar kurilensis G.M. Kamenev, 2007
Anadara kurosedaniensis (FOSSIL) K.M. Hatai & S. Nisiyama,1939 †
Bathyarca kyurokusimana (S. Nomura & K.M. Hatai,1940)
Arca labiata D.C. Solander, 1786
Anadara labiosa (G.B. I Sowerby, 1833)
Barbatia lacerata (C. Linnaeus, 1758)
Acar lamellosa (FOSSIL) G.P. Deshayes, 1858 †
Barbatia landesi (FOSSIL) (C.S. Weaver& K.V.W. Palmer, 1922 †)
Arca larkhanaensis (FOSSIL) d'Archaic, 1850 †
Arca lata (FOSSIL) Münster, 1841 †
Barbatia legayi (FOSSIL) Rigaux & H.É. Sauvage,1868 †
Barbatia legumen (É. Lamy, 1907)
Taeniarca leonensis (FOSSIL) (W.C. Mansfield, 1932 †)
Acar lepidoformis J. de A. Francisco, J.C.N. Barros& S.F.B. de Lima, 2012
Cunearca lesueuri (FOSSIL) (W.H. Dall, 1848 †)
Anadara lienosa (T. Say, 1832)
Barbatia lignitifera (FOSSIL) T.H. Aldrich, 1908 †
Barbatia lima T.A. Conrad, 1848
Barbatia limatella (FOSSIL) R. Tate, 1886 †