578 



Mr. D. M. S. Watson on some 



the nmer side of the surangular and angnhir until it passQS 

 inside tlie splenial nearly to its symphysis. The enormous 

 development of this bone occurs in all Anomodonts, and is 

 no doubt correlated with the great massiveuess of the whole 

 jaw. 



Therocephalia. 



Scymnosiichus whaitsi. Broom, is taken as the type of the 

 Therocephalia, of which it is a fairly primitive member. 

 The material on which the description is founded consists of 

 the two rami of the same lower jaw, the right of which has 

 the bones naturally arranged and exposed from the outer side, 

 whilst tiie left has the bones somewhat displaced, the back of 

 the jaw being separated from the front; this jaw is free from 

 'matrix on all sides. 



Fio'. 3. 



A. Left ramus of lower jaw of Scymtiomchus whaitsi, iurier aspect. 

 li. Right ramus of the same jaw, outer aspect. Teeth omitted. 

 X i . 



The denlary is long and narrow, thick at tiie symphysis, 

 where it is loosely articulated with its fellow, and thinning 

 otF posteriorly to an oblique feather-edge, which overlaps the 

 surangular and angular. There is a large coronoid process 

 which projects freely above the surangular. 



The splenial is a thin strip of bone lying on the inner side 

 of the dentary, and meeting the corresponding bone of the 



