240 M. R. Thorpe — John Bay Promerycochoeri, 



zygoma extends but slightly above squamous suture; 

 malar below orbit very wide and heavy, with its inferior 

 edge strongly convex downward; nasals extend nearly 

 to incisive alveoli; lacrymal fossa well marked, moder- 

 ately deep; orbit triangular, with apex downward and 

 forward; very deep lateral fossse above condyles; no 

 internal cingulum on molars ; bullae large and extending 

 below postgienoid processes ; infra-orbital foramen above 



This peculiar specimen consists of a skull, somewhat 

 laterally compressed, but Avell preserved except for the 

 portion anterior to P^, which is broken away. The left 

 mandible is complete except for the canine and incisors, 

 which are missing. The right ramus has P2, P3, P4, M^, 

 and parts of Mo and M3. The upper contour of the skull 

 is nearly straight, the anterior portion of the nasals being 

 nearly as high as the sagittal crest. The squamous 

 portion of the zygoma is neither heavy nor rugose as in 

 P. macrostegus, and its upper part curves strongly back- 

 ward. The side of the face is divided by the convexity 

 from the anterior zygomatic pedicle, with concavities 

 above and below. The canine convexity is prominent. 



Measurements of Holotype. 



nun. 



Total leng-'th of skull 340* 



Bipostgienoid diameter 104 



Bizygomatic diameter 154 



Length of superior molar series 81.7 



Length of superior premolar series 68 



Depth of malar below middle of orbit 49 



Max. width of cranium 55 



Diameter of postorbital constriction ^ 38 



Max. heig-ht of zygoma above glenoid surface 55* 



Width of f rontals above middle of orbits 95 



Height of skull above parapet of M'^ 106 



Width of face at infra-orbital foramina 67 



Leng:th of nasal bones 145 



Length of inferior molar series 82 



Length of inferior premolar series 73 



Depth of ramus from condyle to angle 137.5 



Length of ramus 255* 



* Approximate. 



