SCIURUS. 221 



the fur is of this colour, it is long and coarse, and the under parts are less brilliant. 

 These phases are probably seasonal and connected with the breeding period. Certain 

 skins obtained by me at Teng-yue-chow in Yunnan belonged to the black, glossy 

 kind, with rather bright, yeUow under surfaces. 



A race found in Arracan, Pegu, and Tenasserim, has generally the dorsal region, 

 from behind the shoulders to the sacral region, and the sides, pale brown or yellowish- 

 brown, nearly as pale as in S. bicolor var. sondaica, Horsfd., the rest of the upper 

 parts being dark or blackish-brown, and the tail almost black, but sometimes washed 

 with yellowish. In some, the pale colour even extends to the upper siu-face of the 

 head and neck. These squirrels have all the characters of being transitional between 

 ^S*. bicolor var. sondaica and S. giganteus, M'Olelland. They are, however, larger 

 than the former, and they are connected with the latter by their skulls and the size of 

 their teeth, but their nasals are most variable, and they appear to be generally longer 

 and narrower than in typical S. giganteus. Some examples, however, have the 

 short and broad nasals of that species, so that it is impossible to separate them 

 specifically, although they appear to be a well-marked race of the giant squirrels, 

 more nearly afiined to S. giganteus than to ^S*. bicolor, though perhaps in its 

 peripheral characters this race more resembles the latter than the former. 



The skull of S. giganteus is about the same size as the skull of S. maximiis. 

 Its most distiuctive feature, iu specimens from Sikkim and Assam, is the broad 

 character of the inferior end of the nasals, their upper ends being but little 

 expanded. This confers great breadth on the muzzle, wMch is markedly different 

 from the muzzle of skulls corresponding to S. bicolor var. sondaica, Horsfd., S. hypo- 

 leucus, Horsfd., S. auriventer, Geoff., and S. ephippium, M. & S., than all of which 

 the skull of S. giganteus is much larger. Specimens from Tenasserim, Pegu, and 

 Arracan with pale backs, have their skuUs distinguished by much less dUated nasals, 

 as a rule, but examples occur in wliich these bones resemble the dilated nasals of 

 typical S. giganteus, and the occurrence of such skulls serves to connect the more 

 aberrant forms with the type. Not only the nasals of these skuUs vary, but also 

 the length of their molar line. The skulls and teeth, however, conform in size to 

 S. giganteus and not to S. bicolor. It is important to note that these Tenasserim, 

 Pegu, and Arracan specimens which show a tendency to resemble the skulls of 

 squirrels referable to >S'. bicolor var. sondaica, S. liypoleucus, S. auriventer, and 

 ^S*. ephippium also manifest a disposition to resemble them in the colour of their fur ; 

 but the animals in the aggregate of their external characters are more alHed to 

 S. giganteus than to *S'. bicolor. Some examples of S. giganteus from Upper Burma, 

 otherwise inseparable from the type, show an intermixture of pale-brownish hairs 

 on the back, and thus a tendency to conform to the features of these Tenasserim, 

 Pegu, and Arracan squirrels, which on their part manifest a tendency to pass into 

 ^S*. bicolor, var. sondaica, &c. ; and had it not been that the skulls of squirrels from 

 these latter localities conformed more to the type of B. giganteus than to S. bicolor, I 

 would have been inclined to regard them as a variety of that species. As it is, they 

 seem to me to link the two forms together. At first, and before I had observed a 



