Hemicythara octangulata (R.W. Dunker, 1860)
Bela odhneri (FOSSIL) Harmer †
Liracraea odhneri A.W.B. Powell, 1942
Liracraea odhneri benthicola R.K. Dell, 1956
Mangelia odovychenae (FOSSIL) Scarponi & al., 2016 †
Oenopota ogasawarana T.A. Okutani, K. Fujikura& T. Sasaki, 1993
Oenopota okudai T. Habe, 1958
Obesotoma okutanii I.P. Bogdanov & K. Itô,1992
Mangelia oldroydi R. Arnold, 1903
Mangelia olivieriana J.C. Melvill, 1917
Leiocithara opalina (E.A. Smith, 1882)
Liracraea opimacosta (FOSSIL) Richardson, 1997 †
Mangelia ordinaria (E.A. Smith, 1882)
Bela orientalis K.H.J. Thiele, 1925
Eucithara oriza (R.B. Hinds, 1843)
Guraleus ornatus (G.B. III Sowerby, 1896)
Mangelia orophoma J.C. Melvill & R. Standen,1896
Neoguraleus oruaensis A.W.B. Powell, 1942
Mangelia ossea (F. Nordsieck, 1968)
Antiguraleus otagoensis A.W.B. Powell, 1942
Liracraea otakauica A.W.B. Powell, 1942
Oenopota ovalis (H.B.S. Friele, 1877)
Obesotoma oyashio T. Shikama, 1962
Ithycythara oyuana (M. Yokoyama, 1922)
Mangelia paciniana (P. Calcara, 1839)
Granoturris padolina W.G. Fargo, 1953
Bela paesleri H. Strebel, 1905
Mangelia paessleri (H. Strebel, 1905)
Kurtziella pagella (FOSSIL) W.P. Woodring, 1970 †
Eucithara pagoda (W.L. May, 1911)
Toxicochlespira pagoda A.V. Sysoev & Y.I. Kantor,1990
Mangelia painei R. Arnold, 1903
Mangelia pallaryi (F. Nordsieck, 1977)
Kyllinia parentalis (FOSSIL) Garilli & Galletti,2007 †
Ithycythara parkeri R.T. Abbott, 1958