Mastonia clemens (R.B. Hinds, 1843)
Triphora clio C. Hedley, 1899
Coriophora cnodax (F.P. Jousseaume, 1884)
Triphora coelebs R.B. Hinds, 1843
Triphora coetiviensis J.C. Melvill, 1909
Triphora collaris R.B. Hinds, 1843
Inella colon (W.H. Dall, 1881)
Euthymella colzumensis (F.P. Jousseaume, 1898)
Strobiligera compsa (W.H. Dall, 1927)
Triphora concatenata J.C. Melvill, 1904
Triphora concinna R.B. Hinds, 1843
Euthymella concors (R.B. Hinds, 1843)
Latitriphora conferta (C.F. Laseron, 1958)
Bouchetriphora confusa (S. Kosuge, 1963)
Viriola connata (R.P. Montrouzier, 1862)
Bouchetriphora conspersa (E.A. Smith, 1885)
Notosinister constrictus C.F. Laseron, 1958
Coriophora continens (C.F. Laseron, 1958)
Triphora contrerasi F. Baker, 1926
Metaxia convexa (Carpenter, 1856)
Triphora convexa E.A. Smith, 1904
Triphora cookeana F. Baker & V.D.P. Spicer,1935
Opimaphora coralina C.F. Laseron, 1958
Triphora cornuta R.P.J. Hervier, 1898
Viriola corrugata (R.B. Hinds, 1843)
Eutriphora costai Fernandes & A. Pimenta,2015
Triphora costata W.H. Pease, 1871
Triphora crassigranulata (FOSSIL) (J.P.J. Ravn, 1933 †)
Mastonia crassula (E.C. Von Martens, 1880)
Euthymella crenulata (G.P. Deshayes, 1863)
Triphora cretacea (FOSSIL) (J.P.J. Ravn, 1933 †)
Metaxia crosseana (N. Tiberi, 1863)
Coriophora cybaea (S. Kosuge, 1963)
Triphora cylindrellus (W.H. Dall, 1881)
Triphora cylindrica W.H. Pease, 1871