580 



Mr. D. M. S. Watson on some 



The splenial is a narrow strip of bone lying on the inner 

 side of tlie dentary and having a relatively large symphysis. 



The coronoid is a large thin film of bone tightly ])ressed 

 onto the inner side of the dentary and overlapping the snr- 

 angular and prearticiilar at the back. It is remarkably 

 siniihir to the corresponding bone in Sci/mnosuchiis. 



The snraiigular is a narrow sheet of bone whose outer 

 surface is largely covered by the angular and dentary ; its 



1' i"-. 4, 



Left ramus of lower jaw of Cinwjiyinthvs c7-ateronottis, iiiuer aspect, 

 K liiglit ramus of the same jaw, outer aspect. Teeth omitted. 



X i 



inner face must be applied to the articular, but in no specimen 

 is the suture between the two bones visible. 



Tlie angular is a plate of bone thickened below and covering 

 a large part, of the outer face of the surangular ; its lower 

 border has the usual notch placed very far forward and pro^ 

 vided with a vestigial reflected lamina, not completely pre-t 

 served in Cynognathus, but very well shown in iJiademodon. 



The articular is a small bone almost completely surrounded 



