with Descriptions of Neiv Species. 



235 



The palatal vault is wide and up-arched, with the dental 

 parapet projecting well below. The concavity in P. 

 macrostegus and in P. clielydra is greater. The width of 

 the palate at the hypocone of M^ is 64 mm. ; at P^, 55 mm. 

 The metastyle of ]\P is very robust and the tooth as a 

 whole is more like that of P. superhus than of P. macros- 

 tegus. The triturating surface of M^ is completely 

 obliterated, although this has been brought about in a 

 somewhat different manner than in Merycoclwrus. The 

 muzzle is compressed, being 81 mm. in depth at P^ The 

 posterior nares are very large and the basicranial axis 

 is steep. 



Fig. 3. 



Fig. I 

 Y. P. M 



-P romerycoclwerus inflatus, "sp. uov, 

 Eight lateral view of skull. X "/i- 



Cat. No. 10233, 



Pr ornery coclioents inflatus, sp. nov. 



(Fig. 3.) 



Holotype, Cat. No. 10233, Y. P. M. Upper Oligocene (upper John Day), 

 Bridge Creek, John Day Kiver, Oregon. 



Specifi^c characters. — Skull very robust and massive ; 

 incisive foramina large, close together, and approach near 

 to incisive alveolar border: bulled robust and rotund, 

 extending slightly below postglenoid process; internal 

 cingula on molar teeth; squamous portion of zygomatic 

 arch very light proportionally, its posterior ascending 

 section rising not above the middle of the orbit, but the 

 malar section is wide and very robust, originating 

 above the anterior part of JVP, and continuing forward 

 as a convexity which occupies nearly the whole side 

 of the face ; lacrymal fossae very shallow ; cranium 

 very wide and low; frontals very mde and flat; 

 orbits look somewhat upward and forward, but chiefly 

 outward; sagittal crest long and thin; palate wide; 



