EXPLANATION OF PLATE 11. 



Fig. 1. Occipital region of skull, Camptosaurus dispar Marsh. Cat. No. 5473, 

 U.S.N.M. A uat. size. I'o.sterior view. From a photograph. 

 2. Explanatory figure of same, bs, basisphenoid ; exo, exoccipital; /, fora- 

 men magnum; oc, occipital condyle; p, parietal; pf, postfrontal ; pttc, 

 paraoccipital process or opisthotic ; p. pt., process which meets ptery- 

 goid; so, supraoccipital. 



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