On some Goryonopsis Skulls. 



513 



ligure of Scylacognathus /Hirrus. Here however, this median plate 

 seems to be an anterior prolongation of the vertical plates of the 

 pterygoids fused together. In section (.' the median hone seems 

 continuous with the two side walls of the pterygoids which are here 

 supported by the palatines. 



In the same section the pterygoids are seen to continue forward 

 between the palatines and the prevomers; although on the palatal 



PT 



Fig. 8. 



Un-named form (S. A. M. Cat. No. 3:53(1). 



a. Median longitudinal section of skull. 



b. Cross section at A A. 

 Cross-section at BB. 



c. 



d. Cross-section at CC. 



surface they disappear some distance behind the posterior border of 

 the internal nares. There is no median plate of bone on the palate. 

 Moreover the parasphenoid prolongation of the basisphenoid seems 

 to end just above the plane of the pterygoid flanges, where it is 



