188 



Annals of the South African Museum. 



the brain-case figured by Watson in Diademodon ; but it differs 

 in being obviously marked off by suture from the pterygoid. 

 Broom figures the same bone as the alisphenoid. 



The transpalatine articulates anteriorly with the palatine and 

 maxilla and medially with the pterygoid. In the suture between 

 the pterygoid and transpalatine there is a very small pit which 

 may be looked upon as the relic of the suborbital vacuity of the 

 Therocephalia. 



WHAITSIA PLATYCEPS Htn. 



FIG. 50a. Transverse section just behind "transverse bar" of 

 type. 



FIG 50b. Section across distorted snout of co-type. 



FIG. 50c. Section of prevomer just in front of "transverse bar ' 

 in type. 



The palatine articulates \\ith the maxilla laterally, with the 

 pterygoid medially, and anteriorly it meets the prevomer. The 

 larger portion of the bone is vertical. Laterally it has a narrow 

 horizontal portion lying alongside the maxilla and approximating 

 to the bone on the other side to foreshadow the formation of a 

 secondary palate. Then it bends abruptly at right angles, especially 

 in its anterior half, and is again bent to form with the pterygoid 

 and prevomer a plate considerably higher than the level of the 

 edge of the maxilla. 



The palatal portion of the maxilla broadens rapidly behind 

 the canine and passes back to form part of the anterior border 

 of the pterygoid vacuity. Its outer process lies under the jugal, 

 which bone is completely shut out from articulation with the 

 pterygoid by the maxilla and the transpalatine. 



