Euspira clementensis (FOSSIL) G.D. Hanna, 1927 †
Magnatica clifdenensis (FOSSIL) Finlay, 1926 †
Natica cliftonensis (FOSSIL) Clark, 1895 †
Benthobulbus coani (L.N. Marincovich, 1975)
Polinices coensis (FOSSIL) (W.H. Dall, 1903 †)
Polinices coensis (FOSSIL) W.C. Mansfield, 1930 †
Natica colima A.M. Strong & L.G. Hertlein,1937
Natica collaris J.H.F. Link, 1804
Naticarius colliei (C.A. Récluz, 1844)
Euspira compressa (FOSSIL) Waring, 1917 †
Natica concavoperculata J.Y. Liu, 1977
Sinum concavum J.B.P.A. Lamarck, 1822
Naticarius concinnus R.W. Dunker, 1859
Conuber conicum (J.B.P.A. Lamarck, 1822)
Natica conradiana (FOSSIL) W.M. Gabb, 1864 †
Tectonatica consimilis (FOSSIL) E. Robba, Pedriali& E. Quaggiotto, 2016 †
Polinices consimilis (FOSSIL) H.F.A. von Ihering,1907 †
Euspira consobrina (FOSSIL) G.P. Deshayes, 1864 †
Tanea consortis (FOSSIL) (Finlay, 1924 †)
Polinices constanti Huelsken & R. Hollmann,2012
Euspira constricta W.H. Dall, 1908
Polinices cora (A.V.M.D. D'Orbigny,1840)
Natica corallina (FOSSIL) Damon, 1860 †
Natica couteaudi A. de Rochebrune& J.F. Mabille, 1885
Natica coxi (FOSSIL) Mukerjee, 1939 †
Cochlis craccoi (FOSSIL) E. Robba, Pedriali& E. Quaggiotto, 2016 †
Euspira cragini (FOSSIL) Stanton, 1947 †
Natica crassa (FOSSIL) P. Nyst, 1843 †
Payraudeautia crassicorda (FOSSIL) E. Robba, Pedriali& E. Quaggiotto, 2016 †
Globisinum crassiliratum (FOSSIL) Finlay, 1926 †
Natica crassiuscula (FOSSIL) J.P.S. Grateloup, 1847 †
Natica crassoperculata H.X. Liu, 1977
Euspira crawfordiana (W.H. Dall, 1908)
Polinella creper (FOSSIL) (J. Marwick, 1965 †)
Sinum cryptostomoides (FOSSIL) (F. Sacco, 1890 †)