OF THE WHITE RIVER BEDS OF MONTANA. 



Measurements. 



Specimen 48. 



It. 



I )epth of jaw at angle of chin 0155 



Greatest width of symphyseal suture 0083 



Distance "between mental foramina 004 



Thickness of ramus behind symphysis 000 



Length of premola r. series 0175 



Length of P T 0042 



Width of P T ooa7 



Length of P* 005 



Width of P-. r ° 032 



Height of crown of 1', 0020 



Length of Pj 0052 



Width of P ¥ ° 031 



Height of P , ° 037 



Specimen GO. 



i (istance between mental foramina 005 



Length of last three premolars •• 014 



Length of Pj ° 042 



Width of P, ' ° 02 



Length ofP. T 005 



Width of P s ° 039 



Length of P t 005 



Width of Pj ° 037 



Length of M T • • 005 



Width of M T anterior (030 



Width of M T posterior 0042 



Height of crown of M , 0024 



259 



lAm.nenetes, gen. nov. 



The skull (No. 49) which I take as the type of this genus was found on a side hill 

 about three miles northwest of Three Forks. It was near vertebrae of a small Titano- 

 therium. The skull most nearly resembles Oreodon gracilis in size, yet it differs more or 

 less from that species in most respects. The most striking characteristics are the following : 



Skull low ; frontal plane nearly flat ; orbits open behind and as high as possible with- 

 out arching of the frontal plane; a separate interparietal ; tympanic bulla} large and 

 longitudinally elliptical; basioccipital sharply angulate ; zygomatic arches nearly parallel ; 

 sagittal crest low. 



This skull belonged to an old animal and the teeth are so worn that their structure 

 cannot be made out. There are other skull fragments with good teeth which were found 

 in the same beds a couple of miles away. There are some differences, but I provisionally 

 refer them to the same genus and describe part of them under the name of P. anceps. 



