1884. 555 (Cope. 
V-shaped, and is in line with the posterior edge of the maxillary bone. The 
latter projects beyond the last molar tooth as far as the anteroposterior 
diameter of the latter. It has no projection in the 0. siémus. There is no 
notch between the maxillary bone and the processes pyramidalis of the 
palatine. The palate is of nearly equal width from the last molar to the 
third premolar ; its roof is gently concave posteriorly ; nearly flat anteri- 
orly. 
The premaxillary bone is a narrow strip which rises nearly vertical- 
ly from its short alveolar border, and is curved outwards above in 
agreement with the expansion of the anterior edge of the maxillary, to 
which it is united by simple suture. The nasal bones are of remarkable 
form. ‘Together they enter the anterior part of the frontals in a V-shape, 
and extend forwards in a narrow shaft. Opposite the anterior borders of 
the orbits the shaft begins to widen gradually, and the surface to flatten, 
until they reach the posterior angle of the ascending part of the maxillary. 
Each one then expands outwards, terminating in a semi-disc which fits 
the concavity of the superior edge of the maxillary above mentioned. 
The entire shape of the nasal bones is that of a spade with a triangular apex 
to the handle, and the short blade at the opposite (anterior) extremity. 
The frontal bone is V-shaped, the angle posteriorly directed, and engaged 
between the pariétal bones, and each branch terminating above each orbit. 
Narrow prolongations extend anterior and posterior to the orbit, joining the 
lachrymal and malar bones respectively. Its median suture is, like that of 
the nasal bones, well defined. The alisphenoid and pariétal have extensive 
connection. The pariétosquamosal suture is horizontal in front ; it then 
gradually rises. It is not associated with a ridge as in some other species. 
The occipital forms the posterior five millimeters of the sagittal crest. 
The nasal opening is subtriangular, with the base above, and is directed 
anteriorly. The facial vacuities are enormous, and excavate the frontals 
to a point which make the anterior third of the orbit’s diameter. They are 
only separated on the median line by the very narrow isthmus of the 
nasal bones. The infraorbital foramen is above the anterior part of the 
fourth surperior true molar. The frontal foramina are small, and are not 
symmetrical. That of the left side is half-way between the median suture 
and the superciliary border; the other is nearer the superciliary border. 
No supraglenoid foramen. Postsquamosal present; that part of the 
cranial walls is injured. The anteroposterior diameter of the orbit ex- 
ceeds the vertical. The auricular meatus is the largest known in the 
family, and it has a prominent border and regularly oval outline. Its 
long diameter rises posteriorly from the horizontal. It is more lateral- 
ly and less posteriorly directed than on the typical and only skull of 
0. simus. The foramen magnum has an openly angulate superior bor- 
der. Jugular, condyloid, and carotid foramina not obvious, owing to the 
close contact of the otic bulla with surrounding bones. oramen ovale 
larger than the 7. lacerum anterius, and external to it in position. 2 ro- 
tundum still larger, inferior in position, bounded on the external side by a 
a 
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