Lymnaea minor W.H. Benson
Radix minutissima (FOSSIL) (Greppin, 1855 †)
Galba modicella (T. Say, 1825)
Lymnaea mongolica (T.C. Yen, 1939)
Lymnaea monnardi (J.D.W. Hartmann, 1841)
Lymnaea montana J.R. Bourguignat, 1888
Walterigalba montanensis (F.C. Baker, 1913)
Stagnicola montenegrinus P. Glöer & V.M. Pešic,2009
Lymnaea mucronata (F. Held, 1836)
Radix namucuoensis Z.X. Qian,J. Yang & J. He, 2012
Lymnaea napasica N.D. Kruglov& Y.I. Starobogatov, 1983
Lymnaea narzykulovi Z.I. Izzatullaev, N.D. Kruglov& Y.I. Starobogatov, 1983
Radix natalensis (C.F.F. von Krauss, 1848)
Zagrabica naticina (FOSSIL) Š. Brusina, 1884 †
Radix navarroi (FOSSIL) (Royo Gómez, 1922 †)
Stagnicola neopalustris F.C. Baker, 1911
Galba neotropica (M.D. Bargues, P. Artigas, Mera y Sierra& al., 2007)
Erinna newcombi H. Adams & A. Adams, 1855
Velutinopsis nobilis (FOSSIL) (A.E. Reuss, 1868 †)
Lymnaea nogoonica N.D. Kruglov& Y.I. Starobogatov, 1983
Lymnaea nogradensis (FOSSIL) (Csepreghy-Meznerics,1954 †)
Lymnaea novikovi N.D. Kruglov& Y.I. Starobogatov, 1983
Radix novorossica (FOSSIL) (Sinzov, 1877 †)
Lymnaea nuttaliana I. Lea, 1841
Fisherola nuttalli (S.S. Haldeman, 1841)
Lymnaea oahuensis L.F.A. Souleyet, 1852
Lymnaea obensis N.D. Kruglov& Y.I. Starobogatov, 1984
Radix obliquata (E.C. Von Martens, 1864)
Lymnaea oblonga (E. Puton, 1847)
Fossaria obrussa (T. Say, 1825)
Valenciennius obsoletus (FOSSIL) (V.V. Bogachev, 1931 †)
Radix obtusissima (FOSSIL) (G.P. Deshayes, 1838 †)
Myxas ollulus A.A. Gould, 1859
Radix onychia (C.A. Westerlund, 1887)
Valenciennius orientalis (FOSSIL) (V.V. Bogachev, 1931 †)