Peterson: The Osteology of Promerycochcerus. 203 



No. 1230 



(Tvpe; 



Mm. 



Skull, greatest transverse diameter 225 



Skull, transverse diameter of occipital condyles 53 



Skull, transverse diameter of occiput at mastoid plate 130 



Skull, vertical diameter of tympanic bulla 33 



Skull, antero-posterior diameter of tympanic bulla 30 



Skull, transverse diameter of tympanic bulla 24 



Skull, greatest transverse diameter of brain cavity 93 



Skull, transverse diameter of the frontals over the orbits 100 



Skull, transverse diameter of muzzle at anterior nares 45 



Skull, greatest transverse diameter of muzzle at base of the canines. 91 



Skull, transverse diameter of palate at the base of incisors 46 



Skull, transverse diameter of palate at p- 60 



Skull, transverse diameter of palate at m- 51 



Skull, transverse diameter of palate at m- 54 



Skull, transverse diameter at base of postglenoid processes 134 



Skull, transverse diameter of postglenoid process at base 24 



Skull, antero-posterior diameter of postglenoid processes at base. ... 13 



Skull, antero-posterior diameter of orbit 36 



Skull, vertical diameter of orbit 34 



Skull, greatest vertical diameter of zygomatic arch 95 



Skull, vertical diameter of jugal below middle of orbit 30 



Lower jaw, length from incisors to base of third molar 167 



Lower jaw, vertical diameter of jaw at m,, approximately •. 55 



Lower jaw, vertical diameter of jaw at canine 58 



THE SUPERIOR DENTITION. 

 (PL.A.TE XL, Fig. 2). 



The crowns of the incisors are very little wider than their bases, so 

 that after comparatively little wear they are peg-like, and resemble 

 those of P. carrikeri in being each separated by diastemata. The 

 crown of the canine is shorter (due to individual variation), and 

 relatively more delicate than in the latter species. In the type, No. 

 1230, which is perhaps the skeleton of a male, the canine is heavier 

 than in any other individual of this species at hand; it has received 

 considerable wear on the posterior face, but was originally much stouter, 

 though somewhat shorter than in Nos. 1232 and 1232c. 



In the type P- is separated from the canine by a short diastema and 

 is also followed by a second very short diastema on the left, while on 

 the right side it is close to Pg-. In Nos. 1232 and 1232a the molars 

 and premolars form a closed series. P- is placed in an oblique position 

 in the alveolar border; a character which seems to be constant in all 



