Retimohnia clarki (W.H. Dall, 1907)
Bathybuccinum clarki Y.I. Kantor& M.G. Harasewych, 1998
Pisania clathrata P. Dautzenberg & H. Fischer,1906
Meteuthria clathratula (K.H.J. Thiele, 1925)
Austrofusus claviculus (FOSSIL) L. C. King, 1933 †
Cominella clelandi (FOSSIL) R. Tate, 1888 †
Limatofusus clementinus (W.H. Dall, 1919)
Aeneator cleryanus (FOSSIL) (A.V.M.D. D'Orbigny,1842 †)
Penion clifdenensis (FOSSIL) (Finlay, 1930 †)
Austrofusus cliftonensis (J. Marwick, 1926 )
Buccinum cnismatopleura (W.H. Dall, 1919)
Buccinum cnismatum W.H. Dall, 1907
Buccinum cnismatum chibanum J.T. Kuroda, 1964
Solenosteira cochlearis (FOSSIL) (R.J.L. Guppy, 1873 †)
Austrofusus coerulescens (FOSSIL) (Finlay, 1930 †)
Aulacofusus coerulescens J.T. Kuroda& T. Habe in T. Habe, 1961
Buccinulum colensoi (H.H. Suter, 1908)
Eocantharus colombiana (FOSSIL) Clark & J.W. Durham,1946 †
Janiopsis colridusensis (FOSSIL) (J.M. Pacaud & Leroy,2015 †)
Neptunea columbiana A.G. Smith, 1958
Fax cominelloides (FOSSIL) (R. Tate, 1888 †)
Siphonalia commoda A. Adams, 1863
Neptunea communis (A.T. von Middendorff,1848)
Neptunea communis clarki (F.B. Meek, 1923)
Cominella compacta (FOSSIL) J. Marwick, 1926 †
Nassicola compacta (FOSSIL) (H.H. Suter, 1917 †)
Buccinulum compactum (FOSSIL) (H.H. Suter, 1917 †)
Aeneator comptus (H.J. Finlay, 1924)
Siphonalia concinna A. Adams, 1863
Caducifer concinnus (L.A. Reeve, 1844)
Aeneator conformatus (FOSSIL) (J. Marwick, 1931 †)
Prosipho congenitus E.A. Smith, 1915
Cominella conica (FOSSIL) Bell A. †
Parvisipho conjunctispira (FOSSIL) A.E.M. Cossmann †
Buccinum conoideum G.O. Sars, 1878