Thyca neritaeformis T. Habe
Eulima newtoni Š. Brusina, 1893
Melanella nilae W. Engl, 2006
Curveulima nishimurai T. Habe, 1958
Eulitoma nishimurai (T. Habe, 1958)
Melanella nisonida (J.C. Melvill, 1906)
Eulitoma nitens C.F. Laseron, 1955
Parvioris nitens (J.W. Brazier, 1876)
Leiostraca nitida (A.E. Verrill, 1884)
Eulima nitidula G.P. Deshayes, 1850
Peasistilifer nitidula (W.H. Pease, 1860)
Ophioarachnicola nitidus (FOSSIL) (J.B.P.A. Lamarck,1804 †)
Melanella nivea (C.B. Adams, 1861)
Leiostraca nixa (A. Adams, 1861)
Eulima nobilis (FOSSIL) R.J.L. Guppy, 1896 †
Parvioris noumeae A. Warén, 1981
Melanella nutans (Mühlfeld, 1824)
Vitreobalcis nutans (J.K. Megerle Von Mühlfeld,1824)
Leiostraca oberon (A. Adams, 1861)
Peasistilifer obesula (C.B. Adams, 1854)
Eulima obliqua (FOSSIL) (F.W. Hutton, 1885 †)
Curveulima obliquistoma P. Bouchet & A. Warén,1986
Hypermastus obliquistomum A. Warén, 1991
Eulima oblonga O. Böttger, 1893
Eulima obtusa L. de Folin, 1870
Hemiaclis obtusa P. Bouchet & A. Warén,1986
Melanella obtusa (C.F. Laseron, 1955)
Bonellia obtusa (H.E. Anton, 1838)
Eulima obtusangula (FOSSIL) Boettger, 1869 †
Eulitoma obtusiuscula P. Bouchet & A. Warén,1986
Melanella obtusoapicata P. Bouchet & A. Warén,1986
Melanella ochsneri (P. Bartsch, 1917)
Melanella odontoidea (A. Adams, 1861)
Enteroxenos oestergreni K.E.H. Bonnevie, 1902
Melanella ogasawarana (H.A. Pilsbry, 1905)