PLATE XII. 



Figs. 1-3. — Undetermined lamnids from Kiowa shales, Lower Cretaceous, en- 

 larged one-half. 



Fig. 4. — f Metiodon abrasus Cragin, enlarged one-half. 



Figs. 5, 6. — Lnmna, sp., from Kiowa shales, enlarged one-half. 



Figs. 7, 8. — Corax curvafus Willist., from without and within, enlarged nearly 

 two diameters. 



Figs. 9-11. — .' Ptychochis janewayii Cope, enlarged. 



Fig. 12. — LcDnna, sp., enlarged nearly two diameters. Kiowa shales. 



Fig. 14. — Ptychodu^ x>oly gyrus, from the side, natural size (the same tooth 

 figured on plate XI, fig. 9). 



Fig. 13. — Ptychodus occidentalis, enlarged nearly two diameters. 



