

45 



major ; and the downward and inward arching of the alveolar 

 border is not marked to the same extent as in that species. 

 The lower border is nearly straight, and has but one slight 

 emargination just -behind the symphysis. The ascending 

 portion of the ramus rises near the last molar quite abruptly, 

 and makes an angle of nearly 90 with the horizontal portion. 

 The masseteric fossa is shallow and obscure, and the anterior 

 bounding ridge is almost obsolete. This part of the jaw is 

 very different from any of the species of Palceosyops. The 

 symphysis is quite long, and extends back as far as the second 

 premolar ; the chin is probably rounded. The dental foramen 

 is situated high up in the ascending portion of the ramus ; 

 the mental foramen is placed below the second premolar ; it 

 is large and single. 



Cranial Measurements, 



M. 



Breadth of frontal at postorbital process 045 



Breadth of frontal in front of postorbital -030 



Breadth of nasal just in front of orbit -032 



Length from angle of nares to end of premaxillary 1235 



Length of premaxillary -056 



Length of maxillary 230 



Breadth of palatine process at canine 026 



Breadth of palatine process at second premolar -029 



Vertical height of maxillary at angle of nares -064 



Breadth of maxillary across floor of orbit -058 



Fore-and-aft diameter of orbit -054 



Length of malar along maxillary -094 



Vertical diameter of malar behind maxillary -029 



Transverse diameter of malar behind maxillary -033 



Fore-and-aft diameter of glenoid cavity (about) -029 



Vertical diameter of squamosal at end of malar articulation -032 



Transverse diameter of squamosal at end of malar articulation -0325 



Length of ramus mandibuli from symphysis to ascending portion -177 



Depth of jaw at last molar -068 



Depth of jaw at second premolar -061 



DENTITION. 



UPPER JAW. The incisors, three in number, are placed 

 close together in a nearly straight line, which does not make 

 so great an angle with the line of molars as in Palceosyops. 

 They increase regularly in size from the first to the third, 

 which is very large. They all have stout rounded fangs, 



