Pisidium magellanicum (W.H. Dall, 1908) Argentina, Santa Cruz
Sphaerium major (FOSSIL) J. de C. Sowerby † UK, England, Wiltshire
Sphaerium mamillanum C.A. Westerlund, 1871 Russia
Sphaerium marisminus Y.I. Starobogatov& A. Korniushin, 1986 Russia
Sphaerium martensi H.A. Pilsbry, 1899 Mexico
Pisidium mausseneti (FOSSIL) Laubriere, 1886 † France, Paris Basin
Pisidium medlicottianum (FOSSIL) Hislop, 1859 †
Pisidium meierbrooki J.G.J. Kuiper & W. Hinz,1983 Bolivia, Lake Titicaca
Eupera meridionalis (T. Prime, 1861) Panama
Sphaerium mexicanum (W.H. Dall, 1905)
Pisidium milium F. Held, 1836 Italy, Albenga
Pisidium minutum (Kozhov, 1936) Russia
Musculium miocaenicum (FOSSIL) T.A. Neubauer& M. Harzhauser, 2014 † Austria
Pisidium mionicense (FOSSIL) T.A. Neubauer, M. Harzhauser& O. Mandic, 2017 † Serbia
Pisidium mitchelli B. Prashad, 1925 Kashmir
Sphaerium miyadii A. Mori, 1933 Hokkaido
Eupera modioliforme (H.E. Anton, 1837) Venezuela
Pisidium moitessierianum A. Paladilhe, 1866 Denmark
Pisidium mongolica (Z.V. Slugina& Y.I. Starobogatov, 2001) Mongolia
Sphaerium montanum C.M. Tapparone-Canefri,1889 Myanmar
Pisidium montigenum J.G.J. Kuiper, 1966 Kenya
Pisidium nevillianum W. Theobald, 1876 Bangladesh
Pisidium nipponense J.T. Kuroda, 1928 Ajiro, Ehime, Japan
Pisidium nitidum L. Jenyns, 1832 England, Norfolk3,5 mm
Sphaerium nitidum S. Clessin, 1976 England, Norfolk3 mm
Sphaerium novaezelandiae (G.P. Deshayes, 1853) New Zealand, Chatham Islands9 mm
Cyclocalyx novaezelandiae (T. Prime, 1862) New Zealand
Pisidium novobritanniae J.G.J. Kuiper, 1967 New Ireland, Bismarck Archipelago
Sphaerium nucleus (S.E. Studer, 1820) UK, England
Sphaerium nyanzae (E.A. Smith, 1892) Lake Victoria
Pisidium observationis (H.A. Pilsbry, 1911) Argentina, Santa Cruz
Pisidium obtusale (J.B.P.A. Lamarck, 1818) Latvia, Vidzerne2 mm
Sphaerium occidentale (J. Lewis, 1856) Alabama
Pisidium ocloya C.F. Ituarte, 2005 Argentina, Jujuy
Pisidium omaguaca C.F. Ituarte, 2005 Argentina, Jujuy