94 Annals of the SoutJi African Museum. 



the supraoccipital forming only a minute portion of its upper border, 

 and the squamosal its outer border only. The condyle is tripartite. 



The squamosal is a very large bone. The skull is peculiar in that 

 the width between the outer edges of the descending processes of the 

 squamosal is its greatest width. 



Lying in the hollowed portion of the exoccipital just outside the 

 condyle is a small rounded foramen for the exit of the 9th, 10th, llth, 

 and 12th nerves. 



No sutures are distinguishable between the basisphenoid, exocci- 

 pital, and quadrate, and no separate quadrato-jugai can be seen. 



The basioccipital forms the lower part of the tripartite condyle, 

 narrows somewhat in front and then widens, forming on either side 

 a large process with an outer concave articular surface, each pierced 

 by the fenestra ovalis. The stapes is absent. The basisphenoid lies 

 in front of the basioccipital and forms part of the anterior surface of 

 the basioccipital process. The centre of the bone is hollowed out, 

 and on the inner sides of the ridges bounding this hollow are the 

 earotid foramina. Laterally and anteriorly the basisphenoid articu- 

 lates with the pterygoid. 



The pterygoid is a long narrow bone passing from the maxilla to 

 the quadrate. It lies on the outer side of the palatine. For a short 

 distance in front of the basisphenoid the two pterygoids unite in the 

 median line. In front of this median pterygoidal plate, between 

 it and the forked posterior end of the vomer is a large pterygoidal 

 foramen. There is the usual posterior lateral process passing to the 

 front of the quadrate. The sphenoidal portion of the pterygoid is 

 very small. 



The lower part of the columella cranii is seen, closely affixed 

 to the outer side of the pterygoid and basisphenoid. 



The posterior nares are large. The outer border is formed almost 

 wholly by the palatine, which passes along the inside of the pterygoid 

 and meets the "vomer" posteriorly. Anteriorly the palatine lies 

 above the pterygoid and has a rugose surface which meets the 

 prernaxilla. The "vomer" is a thin median bone forming the 

 median septum between the posterior nares. Posteriorly it forks, 

 and curves on each side outwards to meet the palatine, passing 

 behind that bone and forming most of the hinder wall of the 

 posterior nares. According to Broom, this bone in the Anomodonts 

 is formed of fused prevomers and is not homologous with the 

 mammalian vomer. 



In front of this median bone there is a pronounced median ridge 

 on the premaxilla which extends forward half the length of the bone. 



