U. S. GEOLOGICAL SURVEY 



MONOGRAPH 55 PLATE XCV 



SKULL OF BRONTOPS ROBUSTUS? 



One-fourth natural size. (See p. 497.) Princeton Mus. 10061, Chadron formation. The specific reference is somewhat doubtful; the skull 

 resembles that of the type of B. rohu^us in the forward pitch of the short horns, in the short nasals, and in the form of the incisors 

 and c 



