Spinicharybdis boucoti (FOSSIL) Rohr & al., 2008 † USA, Alaska, Prince of Wales-Outer Ketchi
Straparollus brevis (FOSSIL) E.K. Yoo, 1994 † Australia, Gunnedah
Euomphalus brooksensis (FOSSIL) E.L. Yochelson & Dutro,1960 † United States, Alaska, North Slope
Amphiscapha browni (FOSSIL) (A. Thomas, 1930 †) Peru, Piura, Talara
Euomphalus bundtzeni (FOSSIL) Blodgett, 1992 † Alaska, Livengood Quadrangle
Nummocalcar bussoni (FOSSIL) Cox, 1969 † Tunisia, Tataouine, Tataouine Nord
Philoxene caementarius (FOSSIL) Blodgett & Johnson,1992 † USA, Nevada, Eureka
Amphiscapha calix (FOSSIL) W.J. Gordon& E.L. Yochelson, 1975 † USA, Wyoming, Johnson
Schizostoma calyx (FOSSIL) (B. Phillips, 1836 †) Ireland, Dublin
Spinicharybdis canteriata (FOSSIL) Rohr & A. Packard, 1982 †
Euomphalus carbonarius (FOSSIL) Sowerby, 1844 † United Kingdom, Scotland, South Lanarkshire
Euomphalus catilliformis (FOSSIL) de Koninck, 1881 † Poland, Jazwica
Amphiscapha catilloides (FOSSIL) (T.A. Conrad, 1842 †) United States, Maryland, Garrett
Euomphalus catillus (FOSSIL) (Martin, 1793 †) China, Guizhou, Bijie
Euomphalus cera (FOSSIL) R. Etheridge jr., 1917 †
Goldfussoceras circinalis (FOSSIL) (G.A. Goldfuss, 1844 †)
Euomphalopterus cirrhosa (FOSSIL) (Lindström, 1884 †) Sweden, Gotland
Schizostoma cirridioides (FOSSIL) E.A.L. Kittl, 1894 † Italy, Veneto, Belluno
Straparollus clymenioides (FOSSIL) J.W. Hall, 1860 † USA, Colorado, Montezuma
Straparollus complanans (FOSSIL) (J. Perner, 1903 †) Czech Republic, Prague
Poleumita conferta (FOSSIL) Lamont † UK, Scotland
Pleuronotus confusus (FOSSIL) J. Perner, 1903 † Czech Republic, Beroun
Euomphalus conradi (FOSSIL) J.W. Hall, 1861 †
Rhabdotocochlis conveximarginatus (FOSSIL) Zhu, 1995 † China, Germu County
Nevadaspira cooperi (FOSSIL) E.L. Yochelson, 1971 † USA, Nevada, Nye
Euomphalus cornudanus (FOSSIL) Shumard, 1859 † USA, Arizona, Cochise
Euomphalus coroniferus (FOSSIL) de Koninck, 1881 † China, Nei Mongol, Ulaan Chab
Schizostoma costata (FOSSIL) Münster, 1841 † Italy, Trentino-Alto Adige, Bolzano
Euomphalus costellatus (FOSSIL) (McCoy) † UK, England, Northumberland
Straparollus cottrelli (FOSSIL) P.D. Montfort 1810 †
Euomphalus crateriformis (FOSSIL) Koninck †
Poleumita crenulata (FOSSIL) (J.J.F. Whiteaves,1884 †) Canada, Ontario, Grey
Straparollus crenulata (FOSSIL) P.D. Montfort 1810 †
Alaionema crenulatum (FOSSIL) (F.B. Meek, 1871 †) United States, New York, Onondaga
Phanerotinus cristatus (FOSSIL) (B. Phillips, 1836 †) Ireland, Longford