S. GEOLOGICAL SURVEY 



MONOGRAPH 65 PLATE CLXXXII 



SKULL OF BRONTOTHERIUM PLATYCaERAS 

 Photograph furnished by the Field Museum through the courtesy of Mr. E. S. Riggs. One-fifth natural size. (See p. 581, also PI. CLXXXI.) 

 Referred skull (Field Mus. 12161), Phinney Spring, S. Dak., Chadron formation, upper beds. The top view shows well the very elongate 

 ftraight-sided skull top and the widely divergent, very flattened horns with their high connediing creft. The zygomatic width and 

 expansion are foreshortened in the photograph 



