PLATE VI. 



Fig. 1, la, lb. — Lamna sulcata Geinitz, after Leidy, natural size. 

 Figs. 2, 2a. — Scapanorhynchus 7'haphiodon (texana) Agassiz, natural size^ 

 after Leidy. 



Fig. .3. — Lepfosty7^ax bicusjndatus Willist., from the side, natural size. 

 Fig. 6. — ScyUiuni {Lamna ?) gracilis Willist., enlarged. 

 Figs. 7, 8. — Scyllium planidens Willist., enlarged. 

 Fig. 5. — Scyllium I'ugosicm Willist., enlarged. 

 Figs. 9, 10. — Fragments of undetermined teeth from Kiowa shales. 

 Fig. 11. — Ciclodus stanto7ii Willist., imperfect right spleuial dentition, natural 

 size. 



Fig. 12. — Crelodus hroivnii Cope, imperfect left splenial dentition, natural size. 

 Figs. 13, 13 «. — Amphibian atlas from Laramie Cretaceous. 



Fig. 11. — Undetermined shark tooth {Coixix?) from Benton of Colorado, en- 

 larged. 

 Figs. 15, 15a. — Leptostyrax hicuspidatus Willist., natural size. 

 Middle figure of plate — Selachian vertebra {Cor ax ?) from Niobrara Cretaceous. 



