PLATE V 



A. Skull of CHASMOSAURUS KAISENI, type, No. 5401 A.M.N.H., 1/8 



natural size. 



B. Skull of PENTACERATOPS STERNBERGII type, No. 6325 A.M.N.H., 



1/14 natural size. 

 Courtesy of the American Museum of Natural History. 



146 



