144 KANSAS UNIVERSITY QUARTERLY. 
inasmuch as this part of the anatomy of these Miocene reptiles 
has hitherto been wholly unknown. It is provisionally referred for 
the present to Xerobates (Testudo) undata Cope, but its specific 
identity is more or less doubtful, inasmuch as the original de- 
scription of the species to which it is referred is very incomplete 
and imperfect. 
The skull is rounded in the premaxillary region, and is rather 
narrow and long. The outline of the base of the skull may be 
described as follows: The sides in front of the anterior margin 
of the infratemporal fosse make an angle of sixty degrees with 
each other; from this same margin to the quadrate an angle of 
twelve degrees. \Seen from the side, the skull thins posteriorly, 
the dorsal and ventral planes making an angle of eight degrees 
with each other. The dorsal plane lies upon the highest portion 
of the supraoccipital crest, and the upper, flattened surface of the 
skull between the orbits; the ventral or basal plane extending from 
the lower margin of the outer maxillary cutting edge through the 
quadrates. Between the two points touched by the dorsal plane 
there is a long, shallow concavity, which merges into the broad, 
shallow depression in the region of the fronto-parietal suture. 
The supraoccipital crest is small, and arches only a little above 
the otherwise gently downward sloping bone. 
The anterior nares are one-third wider than high; they are large 
and quadrilateral. From the highest portion of the cranium 
the face slopes downward and outward, with a smal] degree of 
convexity. The orbits are large and deep, round in outline, 
and look obliquely outward, forward and upward. The sutural 
union between the frontal and postfrontal occurs immediately 
above the middle of the orbit. The postorbital and infraorbital 
bars are thin and plate-like. The skull throughout, in fact, is 
characterized by its general lightness of bone. The supra- 
temporal fose are large, oval, with their long diameter making 
an angle of forty-five degrees with the sagittal plane. They look 
obliquely backward, upward and slightly outward. On the poste- 
rior border of these fosse there is a prominent, quadrilateral, short, 
stout process for muscular attachment. This process is concave 
on its upper and anterior surface, and its long axis stands obliquely 
inward and forward. It is formed by the squamosal and prootic. 
Below the temporal bar there is a broad, deep notch, the plane of 
which looks immediately outward, with only a slight upward and 
forward obliquity. The process from the maxilla extends promi- 
nently backward for about 12 mm. 
ee 
