Fig. 8o. Atlas, axis, and ribs: A, Trinacromerum (Plesiosauria); B, Platecarpus (Mosasauria); 

 C, Baptanodon (Ichthyosauria), after Gilmore; C', Cymbospondylus (Ichthyosauria), after 

 Merriam; D, 6'/)/^f«oa'o« (Rhynchocephalia); E. Nyctosaurus (Pterosauria); ¥ ,Champsosaurus 

 (Choristodera), after Brown; G, Gavialis (Crocodilia); H, Enaliosuchus (Crocodilia), after 

 Jaekel; I, J, Biplodocus (Dinosauria), after Marsh; K, Camptosanriis (Dinosauria), after Gil- 

 more; L, Iguanodon (Dinosauria), after Dollo; M, Chrysemys (Chelonia); N, Iguana (Lacer- 

 tiha); O, Trinacromerum (Plesiosauria); V, Apatosaurus (Dinosauria), after Riggs. 



