194 KANSAS UNIVERSITY QUARTERLY. 
the rays, which is probably one of the hyoids. The museum 
number of the specimen is 316. 
The maxillary is long and slender and of about equal depth from 
the superior condyle backward. The condyle is elevated, but how 
much can not be determined as the superior portion is not pre- 
served. Just beneath the condyle the bone thickens and the outer 
surface contracts inward. External to the condyle there is a broad 
shelf of bone which is very roughly striated. The premaxilary 
surface is not preserved. The alveolar border supports about 
forty-seven teeth as near as can be estimated. They are conical, 
directed slightly inward, and closely set. The crowns present a 
smooth enameled surface. The whole of the posterior portion of 
the bone is finely striated. Just above the alveolar border in the 
anterior half of the bone there are many small nutritious foramina 
leading inward. 
The mandible differs from that of P. /atimentum Cope in not 
having a tooth on the symphysis within the anterior one, and in 
having a greater depth at the coronoid with reference to its length. 
The dentary is short and strongly incurved at the symphysis. 
The symphysis is divided by a groove into an external and an internal 
portion. The external is small and tubercular in its nature. The 
internal is probably the only part that is in contact with its fellow 
on the opposite side and it has a well marked ridge extending 
backward which becomes more indistinct toward the posterior 
portion. This ridge causes the bone to be thickened just below 
the alveolar border. The lower portion of the dentary is thin and 
smooth externally, except on the lower border, where there are short 
and deep strie extending backward. The alveolar border sup- 
ports probably thirty-eight or forty teeth. These are closely set, 
non-striated and directed inward. The external alveolar wall rises 
considerably above the internal. 
The character of the cotyloid cavity can not be made out owing 
to the quadrate being firmly in place. The outer surface of the 
articular is covered with striae which become coarser toward the 
lower portion. 
The head of the quadrate seems to be broad and bifurcated as in 
P. leptognathus. Above the head the bone broadens anteriorly and 
has a strong ridge extending upward along the posterior border. 
The bone supposed to be one of the hyoids, has a broad flat bifur- 
cated extremity, which soon contracts and becomes rod like. The 
other extremity is not preserved. Between the jaws there are 
‘sevéral pieces. of ossified cartilag2 covered with minute denticles 
somewhat resembling shagreen, 
