Arvella manshurica P. Bartsch in O.A. Scarlato,1960
Bathymodiolus manusensis J. Hashimoto & Furuta,2007
Aulacomya maoriana T. Iredale, 1915
Mytella maracaibensis I. Beauperthuy, 1967
Lioberus marensis (FOSSIL) Weisbord 1964 †
Modiolus margaritaceus (S. Nomura & K.M. Hatai,1940)
Septifer margaritanus (FOSSIL) Nomland, 1917 †
Crenella marionensis E.A. Smith, 1885
Mytilaster marioni (É.A.A. Locard, 1889)
Bathymodiolus marisindicus J. Hashimoto, 2001
Brachidontes maritimus (H.A. Pilsbry, 1921)
Modiolus marquezensis (FOSSIL) Garvie, 2013 †
Modiolus martini M.M. Schepman, 1891
Jolya martorelli (J.G. Hidalgo, 1878)
Modiolus matchgarensis (FOSSIL) (J. Makiyama, 1934 †)
Crenomytilus mathewsoni (FOSSIL) (W.M. Gabb, 1869 †)
Modiolus matris H.A. Pilsbry, 1921
Bathymodiolus mauritanicus R. von Cosel, 2002
Crenella maylandensis (FOSSIL) H.D. Russell & Landes,1937 †
Promytilus mazzolenii (FOSSIL) Larghi, 2005 †
Septifer mediocris (FOSSIL) Devjatilova, 1981 †
Modiolus meganosensis (FOSSIL) Clark & Woodford, 1927 †
Solamen megas (W.H. Dall, 1902)
Perna meleagrinoides (FOSSIL) Hislop, 1859 †
Choromytilus meridionalis (C.F.F. von Krauss, 1848)
Arcoperna micans (FOSSIL) (A. Braun, 1851 †)
Modiolus micropteris (FOSSIL) †
Mytilus middendorffi (FOSSIL) Grewingk †
Septifer mifunensis (FOSSIL) Tamura, 1976 †
Dacrydium minimum T.A. Okutani & Izumidate,1992
Modiolus minimus (FOSSIL) Sowerby, 1818 †
Mytilaster minimus (G.S. Poli, 1795)
Crenella minuta K.H.J. Thiele& S.G.A. Jaeckel, 1931
Musculus minutus O.A. Scarlato, 1960
Mytilus miocenum (FOSSIL) L. Krishtofovich, 1964 †