U. S. GEOLOGICAL SURVEY 



MONOGRAPH 55 PLATE CLXIX 



A, 



SKULL REFERRED TO BRONTOTHERIUM HATCHERI 



:e p. 563.) Am. Mxis. 1070, Hat Creek Badlands, Nebr., Chadron formation. A<, Upper dentition. 

 One-third natural size. The generic characters are well shown; incisors large, canines swollen, 

 premolars wide and submolariform -w^ith large circular internal cusps, external cingula absent, 

 internal cingula thick and -wrinkled, molars wide, with large proto^yles and hypocones, cingula 

 veitigial. The molars of the right side have been elongated by crushing. A^, Front view of skull. 

 OnC'fourth natural size. . The horns are short and thick, with lowr connetfting cre^. The infra- 

 orbital canal, as in other brontotheres, is subcircular. The dimensions of the ja-w belonging with 

 this skull (PI. CLXVIII) do not differ greatly from those of the type jaw of Brontoth^ium gigas 

 Mirsh 



