Drymaeus membielinus J.C.H. Crosse, 1867 Colombia
Drymaeus membranaceus (L.A. Reeve, 1849) South America
Bulimulus mendozanus P. von Ströbel, 1874 Argentina
Mesembrinus meridanus (L. Pfeiffer, 1846) Venezuela35,9 mm
Bostryx metagyra H.A. Pilsbry& A.A. Olsson, 1949 Peru7,1 mm
Lissoacme metamorphus (H.A. Pilsbry, 1896) Chile
Drymaeus mexicanus (J.B.P.A. Lamarck, 1822) Peru, Cajamarca19 mm
Drymaeus mexicanus primularis (L.A. Reeve, 1849) Peru32 mm
Drymaeus miliaris R.A. Philippi, 1867 Peru
Neopetraeus millegranus E.C. Von Martens, 1885 Peru41 mm
Naesiotus milleri (L. Hoffman, 1987) Mexico, Sonora
Drymaeus miltochrous J.A. Albers, 1854 Colombia
Naesiotus minutissimus J.J. Parodíz, 1962 Bolivia
Scutalus minutus A.S.H. Breure, 1978 Peru
Bostryx modestus (W.J. Broderip, 1832) Peru, Lima26 mm
Bostryx modestus angelmaldonadoi W.K. Weyrauch, 1960 Peru, Lima12 mm
Bulimulus moei J.J. Parodíz, 1962 Argentina
Bulimulus mollicellus L.A. Reeve, 1849 South America17,2 mm
Bulimulus monachus (L. Pfeiffer, 1857) Peru23 mm
Bostryx moniezi P. Dautzenberg, 1896 Bolivia12,4 mm
Mesembrinus monilifer (L.A. Reeve, 1848) South America26,3 mm
Drymaeus montagnei (A.V.M.D. D'Orbigny,1836) Bolivia, Santa Cruz23,3 mm
Naesiotus montezuma W.H. Dall, 1893 California
Bostryx monticola A. Doering, 1879 Argentina13 mm
Rabdotus monticola W.H. Dall, 1893 South America
Naesiotus montivagus (A.V.M.D. D'Orbigny,1835) Bolivia20,5 mm
Naesiotus montivagus chacoensis C.M.F. Ancey, 1897 Bolivia20,9 mm
Bostryx mordani A.S.H. Breure, 1978 Peru, Lima22,5 mm
Drymaeus morenoi H.B. Preston, 1907 Argentina
Mesembrinus moricandi (L. Pfeiffer, 1847) Guatemala23,6 mm
Mesembrinus moritinctus (E.C. Von Martens, 1893) Mexico, Acapulco25,2 mm
Mesembrinus mossi (E.A. Smith, 1896) Trinidad21,8 mm
Mesembrinus moussoni (L. Pfeiffer, 1853) Haiti26 mm
Drymaeus muelleggeri S.G.A. Jaeckel, 1927 Brazil
Mesembrinus muliebris (L.A. Reeve, 1849) Colombia29,9 mm