Platyceras sinuatum (FOSSIL) J.W. Hall, 1859 †
Platyostoma speciosum (FOSSIL) (Sedgwick & Murchison,1840 †)
Spinyplatyceras spinosa (FOSSIL) (G.A. Goldfuss, 1844 †)
Platyceras spirale (FOSSIL) J.W. Hall, 1859 †
Platyostoma spirata (FOSSIL) (de Sowerby & Murchison,1839 †)
Platyceras squamosus (FOSSIL) Trenkner, 1868 †
Cyclonema statshiunaica (FOSSIL) Saladzius, 1966 †
Platyceras steinmanni (FOSSIL) A.H. Clarke, 1899 †
Turbonellina striata (FOSSIL) C. Gemmellaro, 1889 †
Platyostoma strophius (FOSSIL) J.W. Hall, 1862 †
Naticellina suavis (FOSSIL) (J. Perner, 1907 †)
Rhineoderma subcarbonaria (FOSSIL) Keyes, 1894 †
Platyceras subcirculare (FOSSIL) Kindle †
Platyceras subelegans (FOSSIL) Girty, 1910 †
Platyostoma subglobosa (FOSSIL) Stauffer, 1909 †
Cyclonema sublaeve (FOSSIL) Ulrich & Scofield, 1897 †
Platyceras subrotundum (FOSSIL) Snider, 1915 †
Platyceras subumbonatum (FOSSIL) Northrop, 1939 †
Cyclonema subundata (FOSSIL) Northrop, 1939 †
Cyclonema sulcifera (FOSSIL) d'Eichwald, 1856 †
Cyclonema sulphuriferum (FOSSIL) J. Perner, 1903 †
Cyclonema supralirata (FOSSIL) Rohr & Smith, 1978 †
Platyceras symmetricum (FOSSIL) J.W. Hall, 1862 †
Strophostylus tantillus (FOSSIL) W.J. Gordon& E.L. Yochelson, 1983 †
Visitator tennesseensis (FOSSIL) (Dunbar, 1920 †)
Cyclonema tenuissimum (FOSSIL) Lindström, 1884 †
Platyceras terminalis (FOSSIL) (Whidborne, 1889 †)
Cyclonema textilis (FOSSIL) (Miller, 1897 †)
Cyclonema thalia (FOSSIL) Billings, 1857 †
Platyceras thetis (FOSSIL) J.W. Hall, 1862 †
Cyclonema timidum (FOSSIL) J. Perner, 1903 †
Cyclonema transversum (FOSSIL) Ulrich & Scofield, 1897 †
Strophostylus transversus (FOSSIL) J.W. Hall, 1859 †
Cyclonema trepidans (FOSSIL) J. Perner, 1903 †
Platyostoma triangularis (FOSSIL) Talent & Philip, 1956 †