348 MR. R. OWEN ON THE OSTEOLOGY OF 
by the lateral boundaries of the orbits and the zygomatic arches!. The orbits’ are 
situated higher in the Chimpanzee than in the Orang, and are larger in proportion to 
the entire skull, but their plane is more perpendicular, and they are wider apart. In 
neither the Chimpanzee nor the Orang are the orbits so deep in proportion as in the 
human subject. The supraorbital nerves and vessels leave a slight depression, and do 
not pass through a foramen. The lachrymal bones are entirely confined to the orbit, as 
in the higher Quadrumana. 
A character by which the Chimpanzee approximates more closely than the Orang to 
the human subject is presented by the nasal bone, which projects in a slightly arched 
form beyond the inter-orbital plane, while a trace of its original separation into two la- 
teral elements remains at the lower margin of the now consolidated and single bone: its 
upper expanded extremity was anchylosed with the frontal bone in the adult specimen 
here described. 
The malar bones are largely developed, as in Man and the Quadrumana generally. 
Two or three small foramina are observable on the exterior of the orbital process ; corre- 
sponding foramina, but of much larger size, are constantly met with in the Orang. The 
infraorbital canal is continued unclosed to within 2 lines of the rim of the orbit : it opens 
upon the face by a single foramen. In one young Chimpanzee I have observed a second 
small foramen. In the Orang there are usually three or more infraorbital foramina, as 
in many of the inferior Simie. 
The ascending or nasal portion of the superior maxillary bone, which is of greater pro- 
portionate size than in the human subject, does not mount vertically to the orbits, as in 
Man and some of the lower Quadrumana, (those, for instance, of the genera Cebus and 
Callithriz), but slopes backwards as in the Cynocephali and in the Carnivorous Mammalia, 
but in a less degree. The contour of the upper jaw, from the nasal aperture to the in- 
cisor teeth, is almost straight, while in the Orang it is rendered concave by the greater 
development of the intermaxillary bones’in the anterior direction. These bones are an- 
chylosed to the maxillary bones in the adults of both the Chimpanzee and Orang. In 
Simia Satyrus the obliteration of the suture is incomplete until the full development of the 
huge laniarii, but in the Chimpanzee the anchylosis takes place at a much earlier period ; 
although in the young animal, when the first dentition is completed, traces of the original 
separation of the intermaxillary bones from the maxillaries are still visible at the sides of 
the nasal aperture and on the palate external to the foramina incisiva. The situation of 
these foramina is always indicative of the original extent of the palatal process of the in- 
termaxillary or incisive bones, and in no Quadrumana are they so close to the incisive 
teeth as in Man. One of the admeasurements in the subjoined Table shows the relative 
extent of the bony palate anterior to the foramina incisiva in the young and adult 
Orang and Chimpanzee, and proves that the latter species makes a nearer approach to 
Man in this particular. In the human subject, in the foetus of which the existence of 
‘ Compare figg. 1 & 2, Plate LVI. 
