U. S. GEOLOGICAL SURVBV 



MONOGRAPH 55 PLATE CXCII 



SKULL OF FEMALE BRONTOTHERIUM CURTUM 



One-fourth natural size. (See p. 576, also PI. CXC.) Referred skull (Am. Mus. lOOS), Big Badlands, S. Dak., Chadron 

 formation. The premolars and molars show the characters typical of Brontotherium, save that the poilero-intemal 

 cusps of the premolars are not well separated from the antero-internal cusps. The canines are slender. The 

 zygomata, though ^tout, are less expanded than in long-homed males 



