Mr. D. M. S. Watson on the Cynodontia. 515 



long, slender, quadrate ramus running backward in contact 

 with the lower edge of the quadrate ramus of tlie epipterygoid 

 to the region of the anterior end of the process from the front 

 face of the pro-otic. This structure is shown clearly in 



Fig. 6. 



5r. X. 



Qu. Qui 



Thriyiaxodon liorhinus, Seeley. Palate from the type-specimen, the 

 secondary palate in advance of the hinder margin being con- 

 cealed in the known specimens. X 1. 



Reference-letters as before, with : — E.Pt,, epipterygoid ; Ec.Pt., ecto- 

 pterygoid ; Pal., palatine ; Px., pterygoid ; St., stapes ; Yo., 

 vomer ; X., foramen for vagus. 



R. 511 and R. 37Ij1. Anteriorly the pterygoid extends £;>r 

 forward on the pahite, forming the side-walls of the great 

 median groove wiiich h'orm.s the roof of the naso-pharyngeul 



