Rothifruticicola nicosiana maasseni R.A. Bank, 1991
Leptaxis niphas L. Pfeiffer, 1857
Xerosecta nisslei (P.M. Pallary, 1904)
Actinella nitidiuscula (G.B. I Sowerby, 1824)
Leptaxis nivosa (G.B. I Sowerby, 1824)
Leptaxis nivosa calensis R.A. Bank, K. Groh& T.E.J. Ripken, 2002
Lindholmomneme nordenskioldi (C.A. Westerlund, 1876)
Monacha nordsiecki B. Hausdorf, 2000
Lindholmomneme notophila (T.D.A. Cockerell, 1924)
Metafruticicola noverca (L. Pfeiffer, 1853)
Diodontella nubigena W.A. Lindholm, 1929
Helicella nubigena (De Saulcy, 1852)
Xerotricha nubivaga (J.F. Mabille, 1882)
Angiomphalia nucula A.A. Schileyko& T.S. Rymzhanov, 2010
Monacha nummus (C.G. Ehrenberg, 1831)
Amandana nyeli (H. Mittre, 1844)
Amandana nyeli ponsi (J.G. Hidalgo, 1878)
Pyrenaearia oberthuri (C.M.F. Ancey, 1884)
Moreletina obruta (P.M.A. Morelet, 1860)
Actinella obserata R.T. Lowe, 1852
Monacha obstructa (L. Pfeiffer, 1842)
Spirorbula obtecta (R.T. Lowe, 1831)
Helicella obvia (K.T. Menke, 1828)
Helicella obvia pappi H. Schütt, 1962
Harmozica occidentalis B. Hausdorf, 2004
Elbasania occidentalis (P. Subai, 1999)
Trichia occidentalis J. Castillejo, 1986
Monacha ocellata (J.R. Roth, 1839)
Ponentina octoglandulosa D.T. Holyoak & G.A. Holyoak,2012
Hygromia odeca (J.R. Bourguignat, 1882)
Monacha oecali B. Hausdorf& B. Páll-Gergely, 2009
Metafruticicola oerstani B. Hausdorf, B.A. Gümüs& M.Z. Yildirim, 2004
Helicella oertzeni (H. von Maltzan, 1887)
Ciliellopsis oglasae F.L. Giusti & G. Manganelli,1990
Candidula olisippensis (G. Servain, 1880)