200 Annals of the South African Muxtuui 



The jugal is incomplete, but does not seem to have an inferior 

 process. 



The parietal region is narrow and crested. The pineal foramen 

 is small. 



The squamosal is crushed, but appears to approximate fairly 

 closely to that of Diademodon. It has the groove on the posterior 

 surface connected with the external auditory meatus, which does 

 not, however, pass over on to the top of the skull. There is a process 

 directed inwards separating the end of the paroccipital process 

 from that of the pterygoid ; this plate bears one deep notch below, 

 instead of two as in Diademodon. The quadrate is not preserved. 



The basicranial axis has been cleared on its ventral surface, 

 and the side-walls of the brain-case are visible ; and both bear a 

 striking resemblance to the corresponding parts in Diademodon. 

 Anterior to the pterygoid flanges the palate has not been wholly 

 cleared, but posterior to them nearly all the details of structure 

 can be seen. 



The median ridge of the pterygoids is shorter than in Diademodon. 

 Posteriorly it splits into two which form the lateral borders of the 

 triangular area bounded behind by the occipital surface. 



The occipital condyle is imperfect ; but there is no doubt that 

 it was double the left half is wholly preserved and formed by 

 the basioccipital. At the side of it, facing laterally, is a small 

 foramen for the exit of the Xllth nerve. The suture between 

 the basioccipital and the basisphenoid is seen to pass across the 

 basicranium between the two fenestrae ovales. Laterally the 

 basioccipital articulates with the massive paroccipital process 

 but the suture between the two is not visible. The front face of 

 this process is excavated at its inner end to form the posterior 

 border of the fenestra ovalis. Laterally to this the front face is 

 pierced by the pterygo-paroccipital foramen, whose anterior border 

 is formed by the posterior ramus of the " pterygoid.'' 



Behind and medial to the fenestra ovalis is the foramen jugulare 

 which is a deep pit looking entirely downwards. Piercing the 

 anterior wall of this pit is a small foiamen, corresponding to one 

 of those seen in Cynognathus. 



The under surface of the basisphenoid is slightly concave with 

 a low median ridge and two lateral ridges which die out before 

 reaching the fenestrae ovales. There are no distinct basisphenoidal 

 tubera. On either side of the median ridge just behind the suture 

 with the basioccipital are two small pits in the latter bone which 



