Crassispira nana (FOSSIL) (G.P. Deshayes, 1834 †)
Crassispira nana clarae (FOSSIL) A.E.M. Cossmann& G. Pissarro, 1913 †
Naudedrillia nealyoungi R.N. Kilburn, 1988
Otitoma neocaledonica Morassi,Nappo & Bonfitto, 2017
Otitoma nereidum Morassi,Nappo & Bonfitto, 2017
Leucosyrinx nicoya (FOSSIL) A.A. Olsson, 1942 †
Crassispira nigerrima (G.B. I Sowerby, 1834)
Crassispira nigrescens (C.B. Adams, 1845)
Crassispira nina K.H.J. Thiele, 1925
Pilsbryspira nodata (C.B. Adams, 1850)
Inquisitor nodicostatus R.N. Kilburn, 1988
Crassispira nodulosa (FOSSIL) (J.B.P.A. Lamarck,1804 †)
Ptychobela nodulosa (J.F. Gmelin, 1791)
Inquisitor nudivaricosus J.T. Kuroda, T. Habe& K. Oyama, 1971
Pilsbryspira nymphia (H.A. Pilsbry & H.N. Lowe,1932)
Comitas oahuensis A.W.B. Powell, 1969
Pyrgospira obeliscus (L.A. Reeve, 1845)
Antiplanes obesus H. Ozaki, 1958
Crassispira obliquata (FOSSIL) A.E.M. Cossmann, 1889 †
Comitas obliquicosta (E.C. Von Martens, 1901)
Antiplanes obliquiplicata Y.I. Kantor & A.V. Sysoev,1991
Comitas obtusigemmata (M.M. Schepman, 1913)
Crassispira ochrobrunnea J.C. Melvill, 1923
Inquisitor odhneri F.E. Wells, 1994
Lioglyphostoma oenoa (P. Bartsch, 1934)
Crassispira oliva F. Fernandes, E. Rolán& J. Otero-Schmidt, 1995
Knefastia olivacea (G.B. I Sowerby, 1834)
Compsodrillia olssoni J.H. McLean & L.H. Poorman,1971
Crassiclava omia (K.H. Barnard, 1958)
Thelecytharella oneili (K.H. Barnard, 1958)
Comitas onokeana King, 1933
Comitas onokeana vivens R.K. Dell, 1956
Compsodrillia opaca J.H. McLean & L.H. Poorman,1971
Ptychobela opisthochetos R.N. Kilburn, 1989
Comitas opulenta (K.H.J. Thiele, 1925)