Zoological Society. 53 



species of Pteromys, having most of the general external characters 

 of the members of that group ; there are, however, some points of di- 

 stinction between the })resent animal and the large Flying Squirrels, 

 which are important ; of these the most conspicuous are the extra- 

 ordinary scales which cover the under side of the basal third of the 

 tail : these scales are of a pale horn-colour, sixteen in number in one 

 of two specimens before me, and fifteen in the other, and arranged 

 in two longitudinal series : each scale is narrow at the base and broad 

 at the opposite extremity, and in fact nearly of a triangular form ; 

 but as the scales on one side alternate with those of the other, no 

 interstices are left ; they not only cover the under surface of the tail, 

 but overlap the sides ; in this overlapping of the scale a ridge is 

 formed, the extremity of which is produced into an angle ; the 

 point of the angle is directed backwards. The portion of the tail 

 which is thus protected beneath is well clothed with fur above, but 

 the hairs are not long, and the apical portion (which is cylindri- 

 cal) is much less bushy than in the large Flying Squirrels consti- 

 tuting the genus Pteromys. The hinder feet have the heel clothed 

 with fur, but the outer margin beneath is naked, and not densely 

 clothed, as in Pteromys. The lateral flying membrane extends from 

 the wrist to the ankle, and is supported moreover by a long cartilage 

 in front, as in Pteromys; but this cartilage has its origin at the 

 elbow-joint, and not at the wrist, as in the genus just mentioned. 

 The interfemoral membrane extends to the heel, and is moreover at- 

 tached to the sides of the tail, and when expanded forms almost a 

 straight line. 



The ears are large, much longer than broad, and naked, excepting 

 at the base on the outer side, where they are covered with long fur, 

 like that on the body ; the naked portion has a slight flesh-like tint, 

 but is nearly white, as are also (Mr. Fraser's notes state) the naked 

 portions of the feet and the tip of the muzzle. The hairs of the 

 moustaches are very numerous, and although not very thick, are 

 unusually long. The fur is long and remarkably soft, and the hairs 

 of which it is composed are all of one kind ; that is, there are no 

 longer interspersed stronger hairs, such as we usually find in the 

 fur of the Rodents ; the fur on the upper parts is sooty black, but, 

 excepting on the membranes, most of the hairs are rather broadly- 

 tipped with yellowish rust- colour : on the upper surface of the head 

 the colour is replaced by grey ; on the under parts of the body the 

 fur is dirty Avhite ; the throat is blackish, and the under side of the 

 throat is tinted with sooty grey. The under side of the membranes 

 is sparingly clothed with hairs ; towards the margin the hairs are 

 more numerous, and of a blackish tint. 



In the structure of the skull Anomalurus diff'ers considerably from 

 the known species of Sciuricke. All the species of the family, the 

 skulls of which I have had an opportunity of examining (and they 

 are numerous, embracing all the known genera and subgenera), are 

 distinguishable by the possession of a distinct post-orbital process 

 to the cranium ; they have the palate broad, and terminating in a 

 line with the posterior molars, or behind that line ; the molars of 



