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DR. R. BROOM ON SOME NEW 



outwards, it forms tlie back wa.ll of tlie frontal region and the 

 anterior border of the temporal fossa. From the point where it 

 meets the frontal at the orbital margin it passes almost directly 

 backwards, forming most of the posterior half of the upper 

 orbital margin. It then passes downwards behind the jugal to 

 nearly the level of the lower side of the orbit. 



The jugal is a large bone. It forms almost the whole of the 

 suborbital arch and about half of the postorbital. Posteriorly it 

 passes back below the squamosal to near tlie quadrate region. 



The parietals are narrow, and form a median crest which in 

 front is overlapped by the postorbitals. The pineal foramen is 

 rudimentary. 



The back of the skull is not well preserved, the bones being 

 very rotten, but so far as can be seen the structure does not difler 

 from that of typical Therocephalians. 



Text-figufe C. 



Section through skull of Alopecopsis atavus Hi'Dom, immediately behind 

 postorbital arch, 



A section through the skull immediately behind the post- 

 orbital arch shows the relations of the parietals and postorbitals 

 above and the pterygoid below, Avith between them a thin 

 anterior process of the basisphenoid, and above them the feebly 

 developed element which I believe to be the true vomer, but 

 which most others call the paiasphenoid. 



The right mandible is fairly complete and the dentary almost 

 perfect. In front there are three incisors which together measure 

 9 mm., and these are closely followed by a long procumbent canine 

 which has antero-posterior diameter of 8'5 mm. and a height of 

 something over 20 mm. IMiere appear to be no serrations on either 

 the incisors or the canine. Tliough the alveolar margin of the 

 dentary is perfectly preserved, there is no trace to be seen of any 



