178 Annals of the Carnegie Museum. 



terior portion beneath is convex from the glenoid surface to the outer 

 border. The glenoid surface is convex both antero-posteriorly and 

 transversely. The post-glenoid process is broad transversely but not 

 very thick. 



The external auditory meatus is enlarged into a pyriform or wedge- 

 shaped mass of bone with the apex pointing downward. Where this 

 meatus is joined to the auditory bulla this process does not extend 

 downward so far. The tympanic bullae are large but not symmetric- 

 ally rounded as in several of the Oreodonts. They differ on opposite 

 sides of the same skull, and one is larger than the other. One is ap- 

 proximately a quarter of a four-sided pyramid, with the apex pointing 

 downward. The other approaches nearer to a cube. Posteriorly the 

 broad spout-shaped paroccipital processes clasp the bullae closely, as 

 if accommodating themselves to the forms of the bullae. The paroc- 

 cipital processes are rather thin antero-posteriorly, are concave in 

 front and convex — nearly angulate — behind, but are much expanded 

 laterally, as in Merycoc/nvn/s laticeps. The basi -occipital has a median 

 ridge between the tympanic bullae which widens as it approaches the 

 occipital condyles. These condyles are small. Above the foramen 

 magnum is a very convex median ridge bounded laterally below by 

 two deep concavities. 



The two anterior incisors, judging by the remains of the alveoli, 

 were small, the third much larger. The canine was of medium size. 

 Premolar four and the molars have extremely narrow valleys, but the 

 teeth are much worn. The molars are narrow with no ridges on the 

 outer median surfaces of the outer crescents. On the third molar the 

 anterior and median pillars are prominent but there is no large acces- 

 sory lobe at the postero-exterior angle, though there is a small one. 



Measurements. 



Mm. 



Length of^skull along palate, etc 225 



Length of face from posterior margin of orbit 122 



Width of skull at glenoid surface 152 



Width of skull at orbits 155 



Breadth of palate at same place, including molars 74 



Length of upper molar-preniolar series 96 



Length of upper premolar series 5° 



Length of upper molar series 46 



Width of M.2 18 



