South African Fossil Reptiles and Amphibia. 



165 



large and circular, and looks forwards, upwards and outwards. The 

 postorbital bar is feeble. The temporal fossae are fairly long, and, on 

 ; account of the breadth of the parietal region, look mainly outwards. 



The premaxilla is very feeble, and apparently provided with a short 

 internasal process. 



The nasal forms most of the upper and half of the posterior borders 

 of the nostril. It passes back along the top of the snout to meet the 

 frontal in a long suture, and its lower edge articulates with the pre- 

 frontal, lachrymal, and maxilla. There is no septomaxilla visible. 



The maxilla forms most of the small cheek. It passes back under 

 the jugal not quite to the postorbital bar. The lower edge of the bone 



FIG. 41. Myosaitrus gracilis, Htn. Type. No. 3526. Natural size. 



is very thin in the anterior half and the cauiniform process extremely 

 feeble almost non-existent. 



The lachrymal and prefrontal are both fairly small triangular bones 

 whose bases form portions of the antorbital boi'der. 



The frontal is fairly broad and extends back to the level of the 

 parietal foramen, i. e. half way along the parietal bar, forming there a 

 wedge dividing the anterior part of the parietal into two portions. 

 The orbital borders are not raised, and there are no supraorbital' 

 bosses. 



I can find no evidence of a postfrontal. The frontal overlaps the 

 postorbital from the orbital border back to the parietal. 



The postorbital forms the whole of the upper and anterior borders 

 of the temporal fossa. Its downward pi'olongation is weak, but it 

 expands slightly at its articulation with the jugal. 



The preparietal is a narrow rhomboidal bone extending from the 

 parietal foramen to just in front of the plane of the postorbital arch. 



