U. S. GEOLOGICAL SURVEY 



MONOGRAPH 55 PLATE LXIX 



B2 



UPPER AND LOWER TEETH OF PROTITANOTHERIUM 



Progressive Stages. Natural size. (See pp. 379, 380.) A, Protitanotherium superhum, type (Am. Mus. 2501), 

 White River, Uinta Basin, Utah, level Uinta C (true Uinta formation), upper molars (m', m') found 

 associated with type lower jaw. Bi, P. superhum (Am. Mus. 2501), lower premolars of type; B2, the 

 same, inner side view. C, P. entargimatum, type (Princeton Mus. 11242), inner side view of lower premolars 



