Ciliatocardium likharevi A.I. Kafanovin O.A. Scarlato, 1981
Bucardium lillei (FOSSIL) S. Freneix& J. Grant-Mackie, 1978 †
Fulvia lineonotata E. Vidal, 1994
Phlogocardia lingualeonis (FOSSIL) (R.J.L. Guppy, 1866 †)
Acrosterigma linguatigris (FOSSIL) C.J. Maury, 1917 †
Protocardia lingulata (FOSSIL) J. Lycett, 1863 †
Nemocardium linteum (FOSSIL) (T.A. Conrad, 1855 †)
Laevicardium lobulatum (G.P. Deshayes, 1855)
Vasticardium lomboke E. Vidal, 2003
Anechinocardium lorenzanum (FOSSIL) (R. Arnold, 1908 †)
Corculum lorenzi M. Huber, 2013
Granocardium lowei (FOSSIL) (L.W. Stephenson, 1952 †)
Cardium lucerna E. Forbes, 1846
Adacna lucida (I. Borcea, 1926)
Protocardia luggudensis (FOSSIL) Troedsson, 1951 †
Vasticardium luteomarginatum (R.P.A. Voskuil& W.J.H. Onverwagt, 1991)
Protocardia lycetti (FOSSIL) (Rollier †)
Lyrocardium lyratum (G.B. II Sowerby, 1840)
Agnocardia machaporiensis (FOSSIL) (C.J. Maury, 1925 †)
Acrosterigma maculosum (W. Wood, 1815)
Acrosterigma maculosum howense E. Vidal, 1999
Acrosterigma magna (C. Linnaeus, 1758)
Agnocardia mahgoobi (FOSSIL) Abbass, 1972 †
Laevicardium majanatschensis (FOSSIL) V.N. Sinelnikova, 1990 †
Ciliatocardium makiyamae (FOSSIL) (Kamada, 1962 †)
Trachycardium mamillatum (FOSSIL) (Furon 1948) †
Maoricardium mansitii (Y. Otuka, 1937)
Dallocardia manueli (A.C.G. Prado, 1993)
Lunulicardia marcellense (FOSSIL) (Vanuxem, 1842 †)
Vasticardium marerubrum (R.P.A. Voskuil& W.J.H. Onverwagt, 1991)
Acrosterigma marielae B.R. Wilson & A. Stevenson,1977
Pratulum marwicki (FOSSIL) (A.G. Beu & P.A. Maxwell,1990 †)
Titanocardium marwicki (FOSSIL) P.A. Maxwell, 1978 †
Ciliatocardium matchgarense (FOSSIL) (J. Makiyama, 1934 †)
Keenocardium matschiense (FOSSIL) A.I. Kafanov, 1984 †