Fissurella limbata Sowerby, 1835
Diodora lincolnensis B.C. Cotton, 1930
Emarginula lindonensis (FOSSIL) Hudleston †
Diodora lineata Sowerby, 1835
Diodora listeri d'Orbigny, 1842
Zeidora lodderae (R. Tate & W.L. May,1900)
Puncturella longifissa W.H. Dall, 1914
Fissurella longifissa G.B. II Sowerby, 1862
Emarginula macclurgi R.N. Kilburn, 1978
Fissurella macrotrema G.B. I Sowerby, 1835
Emarginula maculata A. Adams, 1863
Macroschisma madreporaria C. Hedley, 1907
Cranopsis major (W.H. Dall, 1891)
Fissurellidea malleata (FOSSIL) R. Tate, 1882 †
Fissurisepta manawatawhia (A.W.B. Powell, 1937)
Zeidora maoria A.W.B. Powell, 1937
Emarginula mareana (FOSSIL) N.E. Weisbord, 1962 †
Rimula mariei (J.B.P.A. Lamarck, 1816)
Diodora marshallensis (FOSSIL) H.S. Ladd, 1966 †
Emarginula marylandica (FOSSIL) Martin, 1904 †
Fissuridea marylandica (FOSSIL) T.A. Conrad, 1841 †
Cosmetalepas massieri G.T. Poppe, S.P. Tagaro& J. Sarino, 2011
Lucapina maullina J. Ramírez-Böhme, 1974
Parmaphorella mawsoni A.W.B. Powell, 1958
Fissurella maxima Sowerby, 1835
Macroschisma maximum A. Adams, 1851
Fissurella mcleani (FOSSIL) DeVries, 2008 †
Fissurellidea megatrema (A.V.M.D. D'Orbigny,1839)
Macroschisma megatrema A. Adams, 1851
Parmaphorella melvilli (K.H.J. Thiele, 1912)
Medusafissurella melvilli (G.B. III Sowerby, 1882)
Tauschia meneghiniana (FOSSIL) (Canavari, 1879 †)
Diodora menkeana (R.W. Dunker, 1846)
Fissurella mesoatlantica L.R.L. Simone, 2008
Diodora meta H.F.A. von Ihering, 1927