492 Mr. J. L. Bonhotc 07i the Squirrels 



second name, but the third name will be that by which it is 

 known whether as species or subspecies. 



My attention having been called to this group while working 

 on some specimens from Siam, I have gone carefully through 

 the large series in the British Museum, with the following 

 results. 



These squirrels may be readily divided into four distinct 

 species and several subspecies or geographical races. The 

 true habitat of all these forms is clearly defined, though from 

 lack of material the exact limits of their range in one or two 

 cases is still doubtful. 



The species are as follows : — 



(1) Batufa * gigantea. — Ranging from the Himalayas, Nepal, 



and Sikkim to Siam and the Malay Peninsula. 



(2) liatufa hicolor, — From Java, Sumatra, the Malay Penin- 



sula, and probably Borneo. 



(3) Ratiifa ojjinis. — Inhabiting the southern portion of the 



Malay Peninsula. 



(4) Ratufa ephipjnum. — From Borneo and the Natunas. 



The study of the group has been much confused by a great 

 mass of names, a large proportion of which belong to one 

 species, viz. R. hicolor^ which varies so much, owing to a 

 total or partial bleaching of its hairs, as to present considerable 

 differences. It is worthy of note that this so-called bleaching f 

 process does not take place in all the species ; in R. gigaatea, 

 for instance, it is absent, although it occurs in R. hicolor^ 

 which overlaps the range of its larger congener in Malacca. 

 In R. hicolor the bleaching is chiefly confined to the body, 

 rarely extending to the limbs, although hardly any two indi- 

 viduals are exactly alike ; in R. affinis, aureiventer, hunguraa- 

 ensiSf and nanogigas it is complete, covering all the upper 

 parts of the body, while in R. ephippium it is almost entirely 

 absent, or, if taking place at all, is confined to the tail. 



* For use of the generic name Ratufa see Thos., P. Z. S. 1897, p. 933. 



t I bave called this ])roce5s "bleachinof," as that Avas the term used by 

 Mr. Oldfield Thomas (Zool. 1890, p. 401) wlien describiij<^ a similar pro- 

 cess in our British squirrel. In default of further knowledge it is perhaps 

 a convenient term to use ; but by employing it I do not necessarily imply 

 that the hair is worn or faded, but merely that it changes in colour to a 

 light yellowish brown. The causes of this change are not known, but 

 Mr. Thomas points out that it is not due to the special action of the 

 summer sun. 



[I certainly meant (and still think) that the change was a true bleaching 

 or fading, due to the action of light. In the case 1 was discussing, the 

 bleaching was already produced by the light of winter and spring, 

 without waiting for the action of the summer sun. — 0. T.] 



