Austrofusus conoideus (FOSSIL) (C.A. von Zittel, 1865 †)
Buccinopsis conradi (FOSSIL) (J. Hill, 1888 †)
Neptunea constricta (W.H. Dall, 1907)
Clivipollia contracta (L.A. Reeve, 1846)
Nassicola contracta (FOSSIL) (Finlay, 1926 †)
Neptunea contraria (C. Linnaeus, 1771)
Antistreptus contrarius (K.H.J. Thiele, 1912)
Neptunea convexa V.N. Goryachev, 1978
Editharus copolygonus (FOSSIL) (Pezant, 1908 †)
Savatieria coppingeri (E.A. Smith, 1881)
Retimohnia corbis (W.H. Dall, 1913)
Colus cordatus (L.M.D. Bellardi, 1871)
Neptunea coreana E.K. Yoo, 1976
Manaria corindoni Fraussen & Stahlschmidt,2016
Engina corinnae M.E. Crovo, 1971
Gaillea coriolis (P. Bouchet & A. Warén,1986)
Euthria cornea (C. Linnaeus, 1758)
Euthria cornea curvirostris (FOSSIL) (J.P.S. Grateloup,1848 †)
Cantharus coromandelianus (J.B.P.A. Lamarck, 1822)
Buccinum coronatum A.N. Golikov, 1980
Manaria corporosis Fraussen & Stahlschmidt,2016
Hesperisternia corrugata (FOSSIL) (W.M. Gabb, 1873 †)
Neptunea costaria K. Fraussen & Y. Terryn,2007
Cominella costata (J.R.C. Quoy& J.P. Gaimard, 1833)
Engina costata W.H. Pease, 1860
Pisania costata K.H.J. Thiele, 1925
Buccinum costatum A.N. Golikov, 1980
Probuccinum costatum K.H.J. Thiele, 1912
Pseudoneptunea costellata (FOSSIL) (J.P.S. Grateloup,1847 †)
Lyrofusus costellatus (FOSSIL) (J.P.S. Grateloup,1845 †)
Eocantharus costellifer (FOSSIL) (G.P. Deshayes, 1834 †)
Coptochetus costousus (FOSSIL) G.P. Deshayes †
Clea costulata M.M. Schepman, 1885
Cantharus costulatus (FOSSIL) J.B.P.A. Lamarck, 1822 †
Siphonalia cotteri (FOSSIL) E.W. Vredenburg, 1923 †