Dacrydium knudseni J.A. Allen, 1998
Septifer koeni S. Nomura
Modiolus koneckii (FOSSIL) Dickins, 1963 †
Musculus koreanus K.W. Ockelmann, 1983
Brachidontes kovatschensis (FOSSIL) Krishtofovich, 1981 †
Mytilus krishtofovichae (FOSSIL) Devjatilova, 1981 †
Musculus krishtofovitchi (FOSSIL) Krishtofovitch, 1964 †
Leiosolenus kuehnelti (K.H. Kleemann, 1977)
Modiolus kurilensis F.R. Bernard, 1983
Exosiperna kuroharai T. Habe, 1961
Musculus lacustre H.P.C. Møller
Leiosolenus laevigata (J.R.C. Quoy& J.P. Gaimard, 1835)
Musculus laevigatus (J.E. Gray, 1824)
Promytilus laevis (FOSSIL) Li & Ding, 1982 †
Arcomytilus laitmairensis (FOSSIL) de Loriol, 1883 †
Perna lamarcki (FOSSIL) G.P. Deshayes †
Idas lamellosus (A.E. Verrill, 1882)
Mytilus lamellosus (FOSSIL) Terquem, 1855 †
Modiolus latecaudatus (FOSSIL) G.B. Pritchard, 1903 †
Musculus lateralis (T. Say, 1822)
Perna latoconvexa (FOSSIL) R.B. Newton, 1895 †
Solamen leanum (W.H. Dall, 1897)
Modiolus leckenbyi (FOSSIL) Morris & Lycett †
Lithophaga lepteces Z.R. Wang, 1997
Lithophaga lessepsiana (L.L. Vaillant, 1865)
Adipicola leticiae Signorelli & Crespo, 2017
Jolya letourneuxi J.R. Bourguignat, 1877
Dacrydium leucoguttatum J. van der Linden& R.G. Moolenbeek, 2004
Arcuatula leucosticta (E.C. Von Martens, 1897)
Brachidontes levesquei (FOSSIL) G.P. Deshayes, 1858 †
Mytilus levesquei (FOSSIL) G.P. Deshayes, 1906 †
Modiolus ligeriensis (FOSSIL) d'Orbigny, 1844 †
Lioberus ligneus (L.A. Reeve, 1858)
Benthomodiolus lignocola R.K. Dell, 1987
Inoperna lilliputensis (FOSSIL) Hodges 2000 †