CLASSIFICATION OF THE SCIURID.E. 243 



ture. There is a well-developed crest on its left side, passing 

 from the apex down to the inferior tooth which is the termination 

 of the crest. Bat although the baculum is long and extends 

 throughout the length of the glans, it shows no trace of crests or 

 processes behind the termination of the crest inferiorly. This 

 baculum differs from that of Eoglaitconys in its length, its simple 

 apex, and the lateral inferior crest. (Text-fig. 28, 0, D.) 



Of this baculum I have seen two specimens, one taken from 

 the spirit-preserved example from the Himalayas in the Zoological 

 Society's collection, the other from an example from Mishmi in 

 the British Museum. 



The baculum of a specimen of Hylopetes phayrei from Burma, 

 in the British Museum, measures 11 mm., and agrees very closely 

 with that of H. alhoniger, but is less markedly upcurled distally 

 and is provided with a larger crest. (Text-fig. 28, E.) 



Ilylopetes, it may be recalled, was regarded by Thomas as a 

 subgenus of Sciuropterus. Since the baculum of Sc. ntssicus does 

 not appear to have been described, it is impossible to give an 

 opinion as to the precise status of Hylopetes. But if, as appears 

 to me probable, the baculum of Sciuropterus russicus resembles 

 that of GlauGomys volans, full generic value should, I think, be 

 given to Hylopetes. 



The baculum of an example of Petinomys fuscocapillus fi'om 

 Ceylon, in the British Museum, is a tolerably stout bone with a 

 sinistral curvature like that of Hylopetes^ the right side being 

 convex, the left side concave, but it has no very marked upward 

 curvatui-e, the upper edge being slightly sinuous and the apex 

 a little raised, almost as in Hylopetes fhayrei. The apex, how- 

 ever, is broader than in Hylopetes and somewhat spatulate, the 

 left margin of the shallow apical hollow being raised into an 

 angular tooth behind. On the lower side of the bone there is a 

 strong crest divided by a notch, about in the middle of the bone, 

 into a short proximal and a long distal portion. The latter, 

 which is angled behind, forms a sinuous curve towards the left, 

 but does not ascend on to the left-hand side of the bone distally, 

 as in Hylopetes, but terminates on the lower side of the expanded 

 spatulate apex. The baculum measures 1 1 mm, (Text-fig. 28, 

 F-H.) 



In view of the affiliation b}^ Thomas of Petinomys with Hylo- 

 petes as subgenera of Sciurojyterus, it is interesting to note the 

 broad general resemblance, associated with marked differences, 

 between their bacula. 



The baculum of Glaucomys volans, judging from two specimens 

 in the British Museum, one of which is ticketed Virginia, is 

 exceedingly long and slender, slightly sinuous in its proximal 

 third, and inclined slightly upwards distally. The extreme apex 

 is bifid, the lower process being rounded, the upper more pointed. 

 On the left side there is a long crest running fi-om the summit of 

 the upper terminal process and ending abruptly behind the left 

 side about one-third of the distance from the proximal end of 



