580 



Mr. D. M. S. Watson 



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

 side of tiie dentary and having a relatively large symphysis. 



The coronoid is a large thin film of bone tightly pressed 

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

 aiigular and prearticular at the back. It is remarkably 

 simihu- to the corresponding bone in Sc/jnmosuchus. 



Tiie surangiilar is a narrow slieet of bone whose outer 

 surface is largely covered by the angular and dentary ; its 



Fitr. 4. 





A. Left ramus of lower jaw of Cynofinathvs crateronotus, inner aspect. 

 il liigbt ramus of the same jaw, outer aspect. Teeth omitted. 

 X h 



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

 is the suture between the two bones visible. 



The 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- 

 served in Cynognathus, but very well shown in iJiadeinodon. 



The articular is a small bone almost completely surrounded 



