Heptilian Lower Jaws, 



583 



llie well-known process on tlie underside of the jaw is formed 

 entirely by the aiio-ular, as Seeley thouglit. 



The articular is a rather la)'oe bone fittuig as a plug into 

 the cavity of the back of the jaw, and extending- rather far 

 iorward ; its outer face is largely covered by the surangulav 



Fi"'. 5. 



A. Left ramus of lower jaw of P(/mifso«//'Hs, inner aspect. B. Right 

 amus of the same jaw, outer aspect. Teeth omitted, x j. 



and angular, and its inner side by the prearticular. The 

 articular face has two cotyli for the condyles of the quadrate. 

 1 he {irearticular is a large bone covering the inner face 

 of the articular^ overlapping the angular, and being itself 

 covered by the splenial and coronoid in front. 



Tliere can be no doubt that the bones which in the pre- 

 ceding descriptions I have called by the same name are 



