Cardium concinnum (FOSSIL) Buch, 1844 †
Trachycardium consors (I, 1833) Panama, Chiriqui Bay
Protocardia contusa (FOSSIL) Healey 1908 †
Agnocardia convexa (FOSSIL) (G.P. Deshayes, 1858 †) France, Picardie9 mm
Ciliatocardium coosense (FOSSIL) (W.H. Dall, 1909 †) Oregon, Coos bay, Astoria formation
Trigoniocardia cordeliae (FOSSIL) C.J. Maury, 1924 † Brazil, Rio Pirabas
Vepricardium coronatum (J.S. Schröter, 1786) Malaysia37 mm
Parvicardium cosmetum (FOSSIL) A.E.M. Cossmann, 1886 † France, Paris Basin8 mm
Agnocardia cossmanni (FOSSIL) (Vincent, 1882 †)
Protocardia costaricensis (FOSSIL) A.A. Olsson, 1922 † Costa Rica, Limón, Talamanca
Cardium costatum C. Linnaeus, 1758 Senegal, Dakar106 mm
Pratulum cottaldinum (FOSSIL) (d'Orbigny 1844) †
Trachycardium cotteri (FOSSIL) Cox, 1931 † India, Rajasthan, Bikaner
Maoricardium coxi (FOSSIL) (J. Hector, 1886 †)
Laevicardium crassum (J.F. Gmelin, 1791) Bahamas53 mm
Chesacardium craticuloides (FOSSIL) (T.A. Conrad, 1845 †) Maryland
Dinocardium credelarum (FOSSIL) (L.R. Cox, 1941 †) Costa Rica60 mm
Onestia crespinae (FOSSIL) Day 1978 †
Papyridea crockeri (A.M. Strong& L.G. Hertlein, 1937) Panama25,1 mm
Acanthocardia ctenolium (FOSSIL) W.H. Dall, 1900 † Florida10 mm
Cardium cuculloides (FOSSIL) R. Tate, 1886 †
Lophocardium cumingii (W.J. Broderip, 1834) Panama38 mm
Acrosterigma cygnorum (G.P. Deshayes, 1855) South Australia48,6 mm
Nemocardium cyprium (FOSSIL) (G.B. Brocchi, 1814 †) Italy, Liguria29 mm
Cardium dalli (FOSSIL) R.E. Dickerson, 1913 †
Cardium dalli (FOSSIL) A. Heilprin, 1887 † Florida145 mm
Cardium dariesi (FOSSIL) A. Dey, 1961 † India, Kerala, Kollam
Trigoniocardia deadenense (FOSSIL) (Mansfield 1932) †
Laevicardium decorticatum (FOSSIL) Wood, 1840 † Belgium78 mm
Afrocardium defrancii (FOSSIL) (G.P. Deshayes, 1858 †) Germany, Rheinland-Pfalz10 mm
Cardium degrangei (FOSSIL) A.E.M. Cossmann, 1895 † France, Aquitaine11 mm
Acrosterigma delectabile (FOSSIL) (P.A. Maxwell, 1978 †)
Trachycardium delicatum (E.A. Smith, 1915) Argentina67,7 mm
Rudicardium denticostulatum (FOSSIL) (Beets 1941) †
Austrocardium denticulatum (FOSSIL) (Baily 1855) †