

U. S. GEOLOGICAL SUEVET 



MONOGRAPH 65 PLATE LXXXIV 



SKULL OF BRONTOPS BRACHYCEPHALUS 



Plate prepared under the direftion of Professor Marsh. One-fourth natural size. (See p. 487. also Pis. LXXXV and LXXXVI.) Nat 

 Mus. 4258, skull F, female, referred to B. hrachycephalus. (According to the records in the U. S. National Museum this xs skull 

 F of the 1886 coUecSion. not skuU F of Hatcher's diary of 1887.) Big Badlands. S. Dak., Chadron formation (Tttanotftermm zone), 

 level middle B (Hatcher). This immature skull is vertically crushed, so that the nasals and horns are tilted upward and bacK- 

 ward, and the apparent breadth of the skuU is increased. The sutures show the participation of both nasals aond frontals in the 

 horns. The lacrLal is represented as entering the outer ridge of the horn. The skull is larger than that of the type and comes 

 from a higher level. The dental measurements are much smaller than in any skull referred to B. dispar 



