THE CRETACEOUS PERIOD. 



177 



Fig. 410. — Skeleton of Triceratops prorsus, Marsh. (T T . S. Nat'l Museum.) 



Fig. 410a. — Triceratops prorsus Marsh, from the Laramie Cretaceous. From a paint- 

 ing by C. R. Knight in the U. S. National Museum. 



