Euthyrhachis blatchleyi (FOSSIL) (Kindle, 1900 †)
Lotzia blodgetti (FOSSIL) Heidelberger & Koch,2005 †
Platyostoma boggsi (FOSSIL) Rohr & al., 1981 †
Ploconema bohemicum (FOSSIL) J. Perner, 1903 †
Cyclonema boreale (FOSSIL) C.M. Poulsen, 1974 †
Platyostoma brownsportense (FOSSIL) Foerste, 1903 †
Platyceras bucculentum (FOSSIL) J.W. Hall, 1862 †
Brokenriveria caelatus (FOSSIL) (G.A. Goldfuss, 1844 †)
Brokenriveria caleata (FOSSIL) (G.A. Goldfuss, 1844 †)
Platyceras callossum (FOSSIL) J.W. Hall, 1859 †
Platyceras canalicatum (FOSSIL) Angelin & Lindström,1880 †
Cyclonema canaliculata (FOSSIL) Angelin & Lindström,1880 †
Strophostylus cancellata (FOSSIL) (J.W. Hall, 1847 †)
Strophostylus cancellata (FOSSIL) Angelin & Lindström,1880 †
Cyclonema cancellatum (FOSSIL) Angelin & Lindström,1880 †
Platyceras carinatum (FOSSIL) J.W. Hall, 1862 †
Keeneia carnarvonensis (FOSSIL) Dickins, 1957 †
Nonorios carnicus (FOSSIL) (Vinassa de Regny,1914 †)
Platyceras chapmani (FOSSIL) Williams & M. Breger,1916 †
Praenatica cheloti (FOSSIL) (Oehlert, 1887 †)
Strophostylus chesterensis (FOSSIL) Thein & Nitecki, 1974 †
Platyschisma cirroides (FOSSIL) F. McCoy, 1844 †
Cyclonema cives (FOSSIL) J. Perner, 1903 †
Platyostoma cliftonensis (FOSSIL) Foerste, 1909 †
Platyceras colonus (FOSSIL) Holzapfel, 1895 †
Platyceras columbinus (FOSSIL) (Whidborne, 1889 †)
Cyclonema compar (FOSSIL) J. Perner, 1903 †
Cyclonema composita (FOSSIL) J. Perner, 1903 †
Platyceras compressum (FOSSIL) Jhaveri, 1969 †
Platyceras compressum (FOSSIL) A.H. Clarke & Swartz,1913 †
Platyceras compressum (FOSSIL) Nettleroth †
Platyceras compressus (FOSSIL) T.A. Conrad 1840 †
Platyceras compressus (FOSSIL) (G.A. Goldfuss, 1832 †)
Platyceras conicum (FOSSIL) (J.W. Hall, 1862 †)
Cyclonema consepultum (FOSSIL) J. Perner, 1903 †