TUPAIIDiE. Ill 



Inches. 



Depth of premaxillary surface to anterior extremity of nasals -12 



„ „ posterior „ „ -23 



Depth through posterior margin of palate .......... '37 



„ „ highest point of parietal ... * p 



Anterior extremity of symphysis to extremity of angular process of lower jaw . . . '87 



„ „ ,, „ condyle -90 



„ „ „ „ coroupid process '89 



Length of alveolar surface -37 



Depth through coronoid process "35 



„ from hase of corono-condyloid notch .......... "20 



Kahitat. — Camboja. 



But to return to the genus Tupaia. As I have had the opportunity, owing to 

 the rich materials in the Indian Museum, Calcutta, to examine the osteological 

 features of this group in detail, I shall here record the result of my observations. 



The skull of Tupaia is moderately elongated, and neither truncated before nor 

 behind, and is most tapered in the facial portion. The parietals are rather full and 

 round, but they do not project much beyond the base of the zygoma, which arches 

 outwardly at right angles as a thin plate of bone which has the glenoid articular 

 surface on its under aspect. The zygoma then bends forward to join the malar, 

 but the temporal fossa defined by it is not large. The orbit is large, circular, and 

 directed outwards and wholly surrounded by bone, and the malar has a large hole or 

 longitudinally extended imperfection of ossification, anterior to its junction with the 

 orbital process of the frontal and the zygoma. The malar is about twice as high as 

 the zygoma, and, before the perforation, is scooped out, as it were, externally. The 

 post-orbital process closing in the orbit behind is flattened from before backwards, 

 so that its external margin is a thin plate of bone, the margins being directed 

 outwards and inwards, and the surfaces looking backwards and forwards. The 

 anterior, inferior angle of the orbit is marked by a triangular process overhanging 

 the lachrymal notch. There is no ridge before the orbit, immediately in front of 

 which the maxillae are convex as far as the first premolar, from which to the second 

 incisor the face is concave on either side, and tapers to the premaxillse, the sides of 

 which are rounded. Over the nasals, the facial portion is convex from side to side. 

 The nasals are long narrow bones of nearly equal width throughout, uniting with each 

 other and with the frontals after the permanent dentition. The premaxillaries 

 reach backwards only about half-way between the anterior extremity of the nasals 

 and the frontals, and the greater part of their maxillary suture disappears with age. 

 Erom the post-orbital process of the temporal, a ridge passes backwards and inwards 

 to the posterior extremity of the parietals to join its fellow of the opposite side, 

 defining a triangular space, and where the two become merged in a short sagittal crest 

 which terminates posteriorly with the lambdoidal sutm^e. The frontals are convex, 

 and the skull is shghtly contracted between the orbits, the constriction culminating 

 at the supra-orbital foramen. The greatest breadth of the skull occurs at the root 

 of the zygomatic arch. The occipital region is directed downwards and backwards, 



