498 Savage and Wyman, External Characters, 
maxillary fissure, its depth remaining uniform to its termination ; 
but in the Engé-ena this canal becomes gradually less deep from 
before backwards, and at the fissure is scarcely obvious.’ 
The second character is derived from the internal walls of the 
orbits, which recede from each other in descending towards the 
floor, thus leaving a large pyramidal space for the lodgment of 
the os ethmoides, and serving to increase the capacity of the 
maxillary sinuses. 
The foramen lacerum of the orbit, which serves to trans- 
mit the IIT, IV, part of the V, and the VI nerves, and which 
in the human cranium has an elongated form, is in the Engé-ena 
very nearly round, having a diameter of only two or three 
lines. The spheno-maxillary fissure is much more narrow and 
contracted, forming only a linear opening between the orbit 
and the zygomatic fossa. á 
The ossa nasi are firmly co-ossified with each other and with 
the surrounding bones, but their outline is sufficiently distinct. 
They have a more triangular form than in the Chimpanzee, 
the apex being much more acute, and on the median line pre 
sentsa ptominent ridge. In four skulls of Chimpanzées the 
nasal orifice is of a triangular form, the angles more oF less 
rounded, and the apex directed upwards; in three of the 
skulls of the Engé-enait is nearly square, and in the fourth ap- 
proaches the triangular form, but the apex is directed down- 
wards. The form of the posterior nares also in the two spe 
cies is materially different; in the Chimpanzée the transverse 
diameter of the orifice exceeds that of the vertical, but n the 
Engé-ena the vertical is twice that of the transverse, a condition 
which results from the elongation downwards of the superior 
maxillary bones; the posterior edge of the palatine bones in 
the new species is emarginated on the median line 9$ e 
S. satyrus, while in the Chimpanzée it is either destitute ' 
an emargination or extended into a spine ; the lower edge of the 
ae = 
^ 
* In an adult cranium of the Chimpanzée belonging to Dr. J. C. Warren, this 
canal posteriorly is completely closed over, as in t 
