Ciliatocardium likharevi A.I. Kafanov in O.A. Scarlato, 1981 Russia, Sakhalin31,2 mm
Bucardium lillei (FOSSIL) S. Freneix& J. Grant-Mackie, 1978 † New Zealand, Kaikoura Peninsula
Fulvia lineonotata E. Vidal, 1994 Philippines, Sulu Sea13 mm
Phlogocardia lingualeonis (FOSSIL) (R.J.L. Guppy, 1866 †) Dominican Republic65 mm
Acrosterigma linguatigris (FOSSIL) C.J. Maury, 1917 † Dominican Republic
Protocardia lingulata (FOSSIL) J. Lycett, 1863 † France, Picardie, Aisne
Nemocardium linteum (FOSSIL) (T.A. Conrad, 1855 †) Mexico, Baja California Sur, Mulegé
Laevicardium lobulatum (G.P. Deshayes, 1855) Philippines, Leyte30,6 mm
Vasticardium lomboke E. Vidal, 2003 Indonesia, Lombok Island
Anechinocardium lorenzanum (FOSSIL) (R. Arnold, 1908 †) United States, Alaska, Aleutians East
Corculum lorenzi M. Huber, 2013 Philippines, Bohol50,8 mm
Granocardium lowei (FOSSIL) (L.W. Stephenson, 1952 †) Missouri
Cardium lucerna E. Forbes, 1846
Adacna lucida (I. Borcea, 1926)
Protocardia luggudensis (FOSSIL) Troedsson, 1951 † Mexico, Sonora, Caborca
Vasticardium luteomarginatum (R.P.A. Voskuil& W.J.H. Onverwagt, 1991) Thailand, Phuket81,5 mm
Protocardia lycetti (FOSSIL) (Rollier †) China, Qinghai
Lyrocardium lyratum (G.B. II Sowerby, 1840) Zanzibar Island32 mm
Agnocardia machaporiensis (FOSSIL) (C.J. Maury, 1925 †)
Acrosterigma maculosum (W. Wood, 1815) Philippines, Balicasag Island30 mm
Acrosterigma maculosum howense E. Vidal, 1999 New Caledonia37 mm
Acrosterigma magna (C. Linnaeus, 1758) Bahamas46,9 mm
Agnocardia mahgoobi (FOSSIL) Abbass, 1972 †
Laevicardium majanatschensis (FOSSIL) V.N. Sinelnikova, 1990 † Western Kamchatka
Ciliatocardium makiyamae (FOSSIL) (Kamada, 1962 †) Russia, Sakhalin
Trachycardium mamillatum (FOSSIL) (Furon 1948) †
Maoricardium mansitii (Y. Otuka, 1937) Vietnam, Nah Trang57 mm
Dallocardia manueli (A.C.G. Prado, 1993) Argentina, Chubut Province67 mm
Lunulicardia marcellense (FOSSIL) (Vanuxem, 1842 †) United States, New York, Herkimer
Vasticardium marerubrum (R.P.A. Voskuil& W.J.H. Onverwagt, 1991) Kenya, Mombasa70 mm
Acrosterigma marielae B.R. Wilson& A. Stevenson, 1977 West Australia, Abrolhos Island
Pratulum marwicki (FOSSIL) (A.G. Beu& P.A. Maxwell, 1990 †) New Zealand
Titanocardium marwicki (FOSSIL) P.A. Maxwell, 1978 † New Zealand
Ciliatocardium matchgarense (FOSSIL) (J. Makiyama, 1934 †) Russia, Sakhalin
Keenocardium matschiense (FOSSIL) A.I. Kafanov, 1984 † Western Kamchatka