SOUTH AFRICAN THEROCEPHALIAN REPTILES. 



349 



teeth. In many skulls wlieii no molars are found we suspect 

 that they may have been lost, but here this can hardly be the 

 case. Both maxillae are well preserved and the dentary as well, 

 yet in none of the three bones is there any trace of molars. 

 Further, the alveolar mai-gin is narrow and sharp, and would be 

 much too slender for the accommodiition of molars large enough 

 to be serviceable to an animal of the si/e. 



The lacrimal is fairly large, and forms a considerable part of 

 the facial surface, which is very smooth. 



The prefrontal forms the anterior a.nd upper quarter of the 

 orbital margin. It meets the frontal, nasal, maxilla, and 

 lacrimal bones. 



The frontals are relatively small, and the two form most of the 



Upper surface of skull of Alopecopsis atavus Broom. 



slio-htlv concave interorbital surface. In front each has a short 

 articulation with the nasal and a nmch longer oblique articulation 

 with the prefrontal, and as the prefrontal nearly extends back- 

 wards to the poster bital. the frontal only forms a very small part 

 of the orbital margin. Posteriorly the frontal has a long articu- 

 lation with the postorbital, and a short interdigitating suture 

 with the parietal mainly hidden by the postorbital. 



There is no postfrontal. 



The postorbital is a peculiarly twisted bone. Its inner end 

 lies against the narrow parietal crest, and from this, passing 



