THE SKULL OF PALEORHINUS 
A WYOMING PHYTOSAUR 
J. H. LEES 
The University of Chicago 
The University of Chicago paleontological expedition to Wyoming 
during the summer of 1904, under the direction of Dr. S. W. Williston, 
secured several phytosaurian skulls in excellent preservation. ‘These 
skulls together with other fossil remains were collected from the Popo 
Agie beds of the Upper Trias of the Wind River region. One of 
these, made the type of a new genus by Dr. Williston and given its 
specific name in honor of its finder, Dr. E. B. Branson, has been 
studied by the writer during the past winter and the results of the 
work are here published. A preliminary announcement of the char- 
acters of this specimen, together with notes regarding the other speci- 
mens found at the same time, was issued some time ago by Dr. Wil- 
liston (this JOURNAL, Vol. XII, 1904, p. 696). 
General characters.—Skull greatly elongated, triangular; snout 
long, slender, depressed. External nares elevated, situated at pos- 
terior extremity of snout, entirely in front of antorbital vacuities, 
separated by downward extensions of nasals. Antorbital vacuities 
large; supratemporal vacuities small, completely enclosed; otic 
foramina present and completely enclosed. Quadrate foramina 
present, small. Squamosal extending but slightly beyond posterior 
margin of quadrate. Median notch of skull nearly in shape of isos- 
celes triangle; notch above quadrate moderately deep. Plane of 
orbits directed obliquely upward. 
Internal nares situated posterior to external, separated by vomers. 
Palatines separated by pterygoids. Vomers long and slender, separ- 
ating pterygoids throughout, extending back to presphenoidal open- 
ing. Pterygoids long, entering into posterior margin of nares between 
palatines and vomers, extending postero-laterally in broad vertical 
plates for union with quadrates. Basipterygoid processes moderate 
in size, enlarged distally. 
