SKELETON IN THE FLYING LEMURS. 145 



causing the superior mandibular arch in front to be likewise broadly 

 curved. (Plate II, figure 3.) In some skulls a smooth, low, longitudinal 

 elevation bounds the nasals upon either side, all to a few millimeters 

 in front (1, 3), but this character is not invaiiably present (3), while 

 in other skulls, the sockets of the canines, and to a lesser degree, the first 

 one or two molars, are indicated on the sides of the maxillaries by 

 smooth, vertical elevations (3), absent in others. 



Posteriorly we find the smooth character of the facial portion carried 

 backward to include the frontal region between the orbits, and the narrow 

 parietal space as far back as the occipital crest. This median parietal 

 space lies between the temporal ridges (the latter are always strongly 

 marked), and is broadest where it passes into the frontal area, gradually 

 contracting as we pass backward, to expand slightly again as it arrives 

 at the occipital crest. Its area is determined by the temporal ridge 

 bounding the temporal fossa upon either side. (Plate II, figure 3.) 



Anteriorly we see the floors of the orbits, and upon either side, the 

 arch of the zygoma, while i^osteriorly the broad, concaved piers of the 

 zygomatic arches look directly upward. Between these is the rather 

 ample, semiglobular cranium or brain-case, either side of which, within 

 the temporal fossa, may exhibit considerable muscular rugosity (1), or 

 it may be comparatively smooth (3, 3). Among the few distinctive 

 characters upon this aspect of the skull are the very prominent post- 

 orbital processes of the frontals. They are more or less raised above the 

 interorbital frontal area and jut out from it upon either side. As the 

 periphery of an orbit is nearly circular in outline each contributes to 

 this circularity at its supero-posterior arc. In some skulls the decurved 

 free extremity of the process is produced backward and downward farther 

 than it is in others, thus more nearly completing the bony circlet of the 

 orljit, especially where the postorbital process of the malar is similarly 

 produced, as it is in some skulls (3). 



The opening for the supraorbital nerve may be either a "notch" or a 

 foramen and, in any case, occurs far forward upon the orbital rim. It 

 is more in evidence in some skulls (1) than in others, and in one of the 

 specimens here being examined it is a notch on the left side and a foramen 

 on the right (1), while in the other two slmlls it is a less conspicuous 

 foramen on both sides. The infraorbital foramen is usually veiy minute 

 in all skulls and can be distinctly seen only upon lateral view. (Plate 

 I, figure 2.) 



Upon regarding the skull from in front there is to be obsen^ed the 

 rather large, circular opening of the anterior nares, through which may 

 be seen the vomer and the scrolled ethmoturbinals, two in number, on 

 either side, with the smaller one beneath. The periphery of the anterior 

 narial orifice may (1), or may not (2, 3), be completed in bone. Owen, 

 in his figures of the skull of Cynoceplialus, has it so completed by the 



