NEW SUBORDER AND NEW SPECIES OF PHYTOSAURUS 535 



From Phytosaurus buceros it differs in the more rounded and 

 shorter posterior process of the squamosal. The lateral temporal 

 opening is larger and more quadrangular in outhne. The antorbital 

 opening was more rounded at the posterior end. The jugal passes 

 forward in a nearly straight line, not bending sharply upward, to 

 form a notch in the lower border of the temporal opening. 



Mehl in his account of the skull of Machaeroprosopus'- has 

 indicated his belief that the form described by him is congeneric 

 with Cope's Phytosaurus buceros; but because he agreed with 

 Jaekel that Cope's form is a distinct genus and because Jaekel's 

 name, Metarhinus, is preoccupied, he suggested the new name 

 Machaeroprosopus. It is far from certain that the European type 

 of Phytosaurus does not occur in North America; Huene has 

 rejected Jaekel's distinction between Phytosaurus buceros and the 

 European forms, and to the author it seems very doubtful on 

 present evidence that such a distinction is justified. For this 

 reason he prefers to refer the new species to the genus Phytosaurs 

 {Machaeroprosopus ?) with Cope's buceros and Mehl's validus and 

 gracilis. 



' Quart. Bull. Univ. Oklahoma, N.S., 103 (1916), p. 21. 



