Carychiella marinae (FOSSIL) (Steklov, 1966) †
Melampus massauensis L. Pfeiffer, 1858
Marinula meridionalis J.W. Brazier, 1872
Blauneria merignacensis (FOSSIL) M.A. Peyrot, 1932 †
Sarnia mexicana (S.S. Berry, 1964)
Carychium mexicanum H.A. Pilsbry, 1891
Carychiopsis michaudi (FOSSIL) (De Boissy, 1848) †
Carychium michelini (FOSSIL) (De Boissy, 1848) †
Carychium minimum O.F. Müller, 1774
Carychium minusculum P.V. Gredler, 1887
Laemodonta minuta (O.F. von Möllendorff,1885)
Ellobium mioxi R.P. Lesson, 1831
Pedipes mirabilis (J.K. Megerle Von Mühlfeld,1816)
Carychium moenanum (FOSSIL) Wenz, 1917 †
Melampus monile (J.G. Bruguière, 1789)
Laemodonta monilifera (H. Adams & A. Adams,1854)
Melampus montrouzieri S.M. Souverbie, 1866
Melampus moreleti H.A. Pilsbry& J.C. Bequaert, 1927
Melampus morrisoni A.M. de F. Martins, 1996
Melampus mousleyi S.S. Berry, 1964
Cassidula mustelina (G.P. Deshayes, 1830)
Myosotella myosotis (J.P.R. Draparnaud, 1801)
Ovatella myotis (FOSSIL) (G.B. Brocchi, 1814 †)
Ovatella myotis pisolina G.P. Deshayes
Ellobium namnetica (FOSSIL) (Vasseur, 1881 †)
Allochroa nana A.M. de F. Martins, 1995
Pythia nana A.R.J.B. Bavay, 1908
Carychium nannodes W.F. Clapp, 1905
Pythiopsis neglecta (FOSSIL) (G.P. Deshayes, 1863 †)
Marinula nigra (R.A. Philippi, 1841)
Carychium nincki (FOSSIL) Cossmann, 1913 †
Carychium nipponense H.A. Pilsbry & Y. Hirase,1904
Pythiopsis nobilis (FOSSIL) (G.P. Deshayes, 1863 †)
Koreozospeum nodongense J.S. Lee, L.A. Prozorova& A. Jochum, 2015
Carychium noduliferum O.W.H. Reinhardt, 1877