116 M. R. Thorpe — Neiv Forms of Agrioclioerus. 



M- (in adult this wonld probably be farther back) ; 

 basicranial axis shallow; iDaroccipitals plate-like and 

 standing at an angle of about 45^ to the sagittal plane; 

 postgienoid robust; basisphenoid nearly fiat between 

 bull^: infero-anterior termination of occipital condyles 

 extends forward below basisphenoid in the shape of a 

 shelf; bulla has a flat, nearly vertical surface facing- 

 inward and backward, joining the paroccipital process ; 

 antero-externally a ridge runs forward and inward 



r2424 , TYPE 

 Y. P. M. 



Fig. 4. — Agrioclioerus tuUatus, sp. nov. Holotype. Left half, palatal 

 view. X 3/5. 



beyond the middle of the glenoid articular surface ; infer- 

 ior surface of bulla keeled, the keel running transversely 

 from the postgienoid tubercle, mth which it is in contact, 

 to the lower border of the internal plane face ; long axis 

 of bulla lies at about a 35-degree angle from the sagittal 

 plane, the anterior portion approaching the pterygoid 

 process, a form of bulla which does not occur in any other 

 species of this genus. 



Measurements. 



mm. 



Skull, total length, occip. condyles to C, inc 175* 



Bizygomatic diameter 102 



Diameter of postorbital constriction 39 



Dentition, P- to M-, inc., length 57 



M- + I\P, length 29 



Brain-case, max. diameter 58 



* Approximate. 



Syxopsis of Species. 



1. Infraorbital foramen above interval between P^ and P^. 

 Size about that of Oreodon culhertsonii; bull« small; pal- 

 ate very steeply uparched; palatonarial border oppo- 



