Alcithoe marlburiana (FOSSIL) L. C. King, 1934 †
Cymbium marmoratum J.H.F. Link, 1807
Metamelon marshalli (FOSSIL) J. Marwick, 1926 †
Scaphella martinshugari (FOSSIL) E.J. Petuch, 1994 †
Volutifusus marylandicus (FOSSIL) E.J. Petuch, 1988 †
Fulgoraria masudae (FOSSIL) I. Hayasaka †
Scaphella matchetti E.J. Petuch & D.M. Sargent,2011
Scaphella maureenae (FOSSIL) E.J. Petuch, 1994 †
Notopeplum mccoyi (FOSSIL) (J.E. Tenison-Woods,1877 †)
Volutoconus mcmichaeli T. Habe & S. Kosuge, 1966
Volutifusus meganucleus (FOSSIL) E.J. Petuch, 1988 †
Nipponomelon megaspira (G.B. I Sowerby, 1844)
Nipponomelon megaspira magna (J.T. Kuroda & T. Habe,1950)
Nipponomelon megaspira prevostiana (J.C.H. Crosse, 1878)
Nipponomelon megaspira prevostiana sagamiensis (T. Shikama, 1980)
Nipponomelon megaspira prevostiana salebrosa T. Shikama, 1967
Volutospina mekranica (FOSSIL) E.W. Vredenburg, 1925 †
Melo melo (J. Lightfoot, 1786)
Melo melo tesselata (J.B.P.A. Lamarck, 1811)
Fulgoraria mentiens (H.C. Fulton, 1940)
Livonia mervcooperi P. Bail & A. Limpus, 2010
Lyria michardi (P. Bail, 2009)
Lyria mikoi (S. Kosuge, 1985)
Melo miltonis (J.E. Gray in E. Griffith& E. Pidgeon, 1833)
Saotomea minima I.P. Bondarev, 1994
Metamelon minima (FOSSIL) J. Marwick, 1926 †
Athleta minutus (FOSSIL) Perrilliat & al., 2006 †
Spinomelon mira (FOSSIL) J. Marwick, 1926 †
Calliotectum mirabile (W.J. Clench & C.G. Aguayo,1941)
Iredalina mirabilis (H.J. Finlay, 1926)
Iredalina mirabilis aurantia (A.W.B. Powell, 1954)
Lyria mississippiensis (FOSSIL) T.A. Conrad, 1848 †
Mitraelyria mitraeformis (J.B.P.A. Lamarck, 1811)
Mitraelyria mitraeformis crassicostata (FOSSIL) (T.A. Darragh, 1988 †)
Mitraelyria mitraeformis grangeri (FOSSIL) (G.B. III Sowerby,1900 †)