Platyceras contortum (FOSSIL) Barrois, 1889 †
Platyceras contortus (FOSSIL) (A. Römer, 1843 †)
Cyclonema convergens (FOSSIL) J. Perner, 1903 †
Platyceras cordatus (FOSSIL) Whidborne, 1889 †
Rhabdocantha cornucapella (FOSSIL) (R. Etheridge jr.,1898 †)
Platyostoma cornutum (FOSSIL) (Hisinger, 1837 †)
Dyeria costatus (FOSSIL) (M.J. James, 1872 †)
Platyceras crassum (FOSSIL) J.W. Hall, 1862 †
Cyclonema crebristria (FOSSIL) (F. McCoy, 1851 †)
Cyclonema crebristria rugata (FOSSIL) Pitcher †
Tubomphalus crenistria (FOSSIL) J. Perner, 1903 †
Cyclonema cushingi (FOSSIL) Ruedemann, 1912 †
Strophostylus cyclostomus (FOSSIL) J.W. Hall, 1864 †
Visitator cylindricum (FOSSIL) Talent & Philip, 1956 †
Platyceras cymbium (FOSSIL) J.W. Hall, 1862 †
Platyceras daschi (FOSSIL) Rohr & Smith, 1978 †
Platyostoma daytonense (FOSSIL) Foerste, 1923 †
Cyclonema daytonensis (FOSSIL) Foerste, 1899 †
Cyclonema decora (FOSSIL) Billings, 1866 †
Platyceras decorum (FOSSIL) Talent & Philip, 1956 †
Platyostoma deforme (FOSSIL) (Sedgwick & Murchison,1840 †)
Platyostoma delicata (FOSSIL) (Talent & Philip, 1956 †)
Cyclonema delicatula (FOSSIL) Lindström, 1884 †
Platyschisma depressa (FOSSIL) Weller, 1900 †
Platyschisma depressum (FOSSIL) J.B.M. Dana, 1847 †
Cyclonema derelictum (FOSSIL) J. Perner, 1903 †
Platyostoma desmatum (FOSSIL) A.H. Clarke, 1904 †
Spiranodus devonica (FOSSIL) (Whidborne, 1889 †)
Spironemella dignitas (FOSSIL) (C.O. Waterhouse, 1963 †)
Platyceras dilatans (FOSSIL) J. Perner, 1911 †
Platyceras dilatatum (FOSSIL) J.W. Hall, 1859 †
Rhineoderma dinglensis (FOSSIL) Girty, 1927 †
Platyceras disciforme (FOSSIL) Lindström, 1884 †
Platyceras dormitans (FOSSIL) Maurer, 1885 †
Cyclonema dowlingii (FOSSIL) (J.J.F. Whiteaves,1906 †)