114 



COMPARATIVE ANATOMY 



orbital septum is present. The frontals and parietals are paired, 

 and there is a parietal foramen. Three bony arcades are seen in 

 the temporal region a superior, an inferior, and a posterior. The 

 quadrate is large, and is firmly fixed to the skull by means of the 



Pmx 



Pmx 



FIG. 81. SKULL OF HATTERIA. A, dorsal ; B, ventral ; and C, lateral view. x-f. 

 (From Gadow, Cambridge Natural History.) 



col, columella auris ; Cond, occipital condyle ; E.P, transpalatine or ectopterygoid ; 

 F, frontal ; Jug, jugal ; Max, maxilla ; Na, nasal ; No, external nostrils ; 

 Pal, palatine ; Par, parietal ; Pmx, premaxilla ; Prf, prefrontal ; Pt.f, post- 

 frontal and postorbital ; Pty, pterygoid or endopterygoid ; Q, quadrate 

 and quadrate- jugal ; Sq, paraquadrate (squamosal) ; Vo, vomer. 



quadratojugal, pterygoid, paraquadrate (" squamosal "), and ex- 

 occipital. The vomers, palatines, and pterygoids are broadened 

 out and form a bony roof to the mouth. An epipterygoid is 

 present. The premaxillse are separated by a suture. Teeth are 

 borne on the maxilla and palatine, as well as on the premaxilla 



