Musculus niger Gray, 1824
Modiolatus nigeriensis (M. Nicklés, 1955)
Lithophaga nigra d'Orbigny, 1845
Dacrydium nipponicum T.A. Okutani, 1975
Musculus nipponicus T.A. Okutani,2005 ex Kuroda MS
Modiolus nipponicus (K. Oyama, 1950)
Mytilus nitens E. Forbes, 1846
Modiolatus nitidus (L.A. Reeve, 1857)
Modiolus nothorine (FOSSIL) A.E.M. Cossmann, 1904 †
Crenella noyamiana (FOSSIL) Kogan, 1964 †
Gregariella nubilis (T. Iredale, 1937)
Lithophaga nuda (FOSSIL) W.H. Dall, 1898 †
Arcomytilus nudus (FOSSIL) Repin, 2013 †
Gregariella obermulleri (E. Fischer-Piette& M. Nicklés, 1946)
Lithophaga obesa (R.A. Philippi, 1847)
Rhomboidella obesa K.W. Ockelmann, 1983
Perna obliqua (FOSSIL) Walton ex MS Lycett †
Perna oblonga (FOSSIL) Seeley †
Dacrydium occidentale E.A. Smith, 1885
Mytilus ochotensis (FOSSIL) Slodkewitsch, 1936 †
Dacrydium ockelmanni Mattson & A. Warén, 1977
Modiolus ocrophaius (FOSSIL) A.E.M. Cossmann, 1887 †
Idas olympicus (FOSSIL) Kiel & Goedert 2007 †
Modiolus omanensis (FOSSIL) Hudson & Jefferies,1961 †
Volsellina ornatissima (FOSSIL) (Johnston, 1887 †)
Brachidontes ornatissimus (FOSSIL) A.V.M.D. A.V.M.D. D'Orbigny, 1844 †
Modiolus ornatus (FOSSIL) W.M. Gabb, 1864 †
Adipicola osseocola R.K. Dell, 1987
Perna oxoniensis (FOSSIL) Paris, 1911 †
Modiolatus oyamai (T. Habe, 1981)
Adipicola pacifica (W.H. Dall, P. Bartsch& H.A. Rehder, 1938)
Dacrydium pacificum W.H. Dall, 1916
Modiolatus pacificus (A.A. Olsson, 1961)
Septifer palanensis (FOSSIL) V.N. Sinelnikova, 1991 †
Mauricia palencae (FOSSIL) Freneix 1957 †