Investigations in South African Fossil Kept ilia and Amphibia.. 69 



The premaxilla carries teeth along its border, as does the maxilla. 



The quadrate is a triangular bone lying between the pterygoid and 

 the quadrato-jugal and squamosal. It appears mostly on the back 

 of the skull, the apex of the bone lying 32 mm. above and some 

 distance internal to the articular surface. This latter is weakly 

 concave, the concavity being directed backwards and outwards 

 from the anterior inner angle of the bone. 



Passing outwards and backwards from the posterior lateral curved 

 border of the parasphenoid is a small, thin, apparently plate-like 

 bone. This may be the stapes. 



FIG. 7. 



Sections across left ramus of lower jaw of RhinesucJius 

 a. 85 mm., behind point of jaw. 

 fi. 185 mm., behind point of jaw. 

 y. 220 mm., behind point of jaw. 



D, dentary; C, coronoid ; Sp, splenial ; A, angular; P. Art, Prearticular ; 

 S.A., surangular. 



The whole of the left side of the lower jaw is preserved, together 

 with the articular region of the right. The length of the jaw is 

 about 322 mm. 



The dentary carries a row of labyrinthodont teeth. It has a 

 narrow posterior elongation extending towards the articular surface 

 for some distance behind the last tooth. 



Lying along the inside of the dentary and extending almost from 

 the front of the jaw to the anterior border of the supra-Meckeliaii 

 fossa is the " coronoid," which throughout nearly the whole of 

 its length bears a large number of small teeth. In the jaws of 

 Trimerorachis and Eryops, as described by Broom and by Williston, 

 this "coronoid" consists of three elements the coronoid proper, 



