Arvella casta (A. Adams, 1862)
Lioberus castaneus (T. Say, 1822)
Crenella caudiva A.A. Olsson, 1961
Modiolus cecillii (R.A. Philippi, 1847)
Mytella charruana (A.V.M.D. D'Orbigny,1842)
Tumidimytilus chejsleveemensis (FOSSIL) (Slodkewitsch, 1938 †)
Gregariella chenui (C.A. Récluz, 1842)
Adipicola chikubetsuensis (FOSSIL) (Amano 1984) †
Bathymodiolus childressi D.L. Gustafson, 1999
Choromytilus chorus (Molina, 1782)
Botula cinnamomeus (J.B.P.A. Lamarck, 1819)
Mytilus cleopatrae (FOSSIL) P. Oppenheim, 1903 †
Gregariella coarctata (Carpenter, 1857)
Musculus coenobitus (L.L. Vaillant, 1865)
Solamen columbiana (W.H. Dall, 1897)
Lithophaga comdigera D'Orbigny, 1847
Modiolus comptus (G.B. III Sowerby, 1915)
Urumella concava I. Hayami & T. Kase, 1993
Lithophaga conchafodentis (FOSSIL) Gardner, 1916 †
Musculus concinnus (R.W. Dunker, 1857)
Mytilus conradianus (FOSSIL) W.C. Mansfield, 1932 †
Mytilus conradinus (FOSSIL) d'Orbigny, 1852 †
Lithophaga consobrina (FOSSIL) K.E.I. von Eichwald,1861 †
Modiolus consobrina (FOSSIL) S.V. Wood †
Idas coppingeri (E.A. Smith, 1885)
Gregariella coralliophaga (J.F. Gmelin, 1791)
Gregariella coralliophaga opifex (T. Say, 1825)
Lithophaga cordata (FOSSIL) J.B.P.A. Lamarck, 1807 †
Musculus corioensis (FOSSIL) R. Tate, 1886 †
Arvella cornea (A. Adams, 1862)
Lithophaga corrugata (R.A. Philippi, 1846)
Mytilus coruscus A.A. Gould, 1861
Gigantidas coseli (FOSSIL) Saether,C. Little & al., 2010 †
Musculus costulatus (A. Risso, 1826)
Modiolus cowlitzensis (FOSSIL) (C.S. Weaver& K.V.W. Palmer, 1922 †)