Natica caseyi (FOSSIL) McNeil, 1984 †
Natica castrenoides (FOSSIL) W.P. Woodring, 1928 †
Natica castrensis W.H. Dall, 1889
Euspira catena (E.M. Da Costa, 1778)
Euspira catena hemiclausa (FOSSIL) (Sowerby, 1824 †)
Euspira catena protracta (FOSSIL) (K.E.I. von Eichwald,1830 †)
Euspira catenoides (FOSSIL) (Wood, 1842 †)
Polinices catenoides W.L. May, 1919
Natica catulli (FOSSIL) Klipstein, 1843 †
Stigmaulax cayennensis (C.A. Récluz, 1850)
Cepatia cepacea (FOSSIL) (J.B.P.A. Lamarck,1804 †)
Notocochlis cernica (F.P. Jousseaume, 1874)
Polinices cerovaensis (FOSSIL) M. Harzhauser & al.,2011 †
Polinices chattonensis (FOSSIL) (J. Marwick, 1924 †)
Sigaretotrema checchii (FOSSIL) E. Robba, Pedriali& E. Quaggiotto, 2016 †
Notocochlis chemnitzii (L. Pfeiffer, 1840)
Sinum chesapeakensis (FOSSIL) G.B. Campbell, 1993 †
Natica chiloensis (FOSSIL) R.A. Philippi, 1887 †
Neverita chipolana (FOSSIL) W.H. Dall, 1892 †
Sinum chipolanum (FOSSIL) W.H. Dall, 1892 †
Euspira chulucana (FOSSIL) A.A. Olsson, 1931 †
Pliconacca cicatricella (FOSSIL) (J. Marwick, 1965 †)
Pliconacca cicatrix (FOSSIL) (J. Marwick, 1931 †)
Natica cincta C.A. Récluz, 1850
Euspira cirriformis (FOSSIL) (J. de C. Sowerby,1824 †)
Polinices citrinus (R.A. Philippi, 1851)
Sigatica clarkeana (FOSSIL) T.H. Aldrich, 1887 †
Sigaticus clarkensis (FOSSIL) T.H. Aldrich, 1911 †
Natica clarki (FOSSIL) Etherington, 1931 †
Sinum clathratum (FOSSIL) (J.F. Gmelin, 1790 †)
Sinum clathratum deshayesi (FOSSIL) (O.G. Michelotti, 1847 †)
Sinum clathratum levesqui (FOSSIL) G.P. Deshayes, 1864 †
Sigatica claudiae (FOSSIL) E. Robba, Pedriali& E. Quaggiotto, 2016 †
Darwinices claudiae (FOSSIL) Griffin & G. Pastorino,2013 †
Polinices cleistopsila K.H. Barnard, 1963