A NEW PHYTOSAUR FROM THE TRIAS OF ARIZONA 149 



The jugals form the 

 lower posterior border of 

 the antorbital vacuity, 

 the lower anterior border 

 of the lower temporal 

 vacuity, and enter 

 slightly in the boundary 

 of the orbit. Along the 

 lower border of the skull 

 their posterior extent is 

 such as to practically ex- 

 clude the quadratojugal 

 from that margin. 



Little or nothing can 

 be said of the squamosal 

 development. 



POSTERIOR VIEW OF THE 

 SKULL 



So much of the skull 

 as seen from the pos- 

 terior side is restored 

 that little of value can 

 be given in description. 

 The skull has been tele- 

 . scoped downward, but 

 it, is evident that it was 

 considerably wider than 

 high. In so many de- 

 tails is the skull like the 

 type of Machaeroproso- 

 pus validus that it is 

 assumed the similarity 

 extends to the posterior 

 side. Some of the dif- 

 ferences in the develop- 

 ment of the region about 

 the supratemporal open- 





'"icrt 



Fig. 3. — Machaeroprosopus andersonl, restored 

 palate surface, slightly over one-sixth natural size. 



