U. S. GEOLOGICAL SURVEY MONOGRAPH 55 PLATE XCIV 



SKULLS OF BRONTOPS DISPAR 



Plate prepared vinder the direa:ion of Professor Marsh. One-sixth natural size. 

 (See pp. 489, 491, also Pis. XCI, XCII, and XCin.) A, Nat. Mus. 4941, skull 

 D, type, reconilrudled from the crushed original; only the front parts of the 

 zygomata are shown. B, Nat. Mus. 4290, skuU K, type of B. validus. The 

 skull is crushed down-ward, thus lessening the height of the narial opening. 

 The horns are rounded in mid-se(5tion, ^vith slender tips, the nasals ^out and 

 broad diftaUy, the buccal s^vellings heavy. The inner incisors are small or 

 absent. C, Nat. Mus. 4245 (erroneously lettered P). A more slender skull 

 Tvhich some-what resembles Allops marshi. (See PI. CXIV) 



