234 RODENTIA. 



terminal ; the banding is so regular that the tail has a ringed appearance, except at 

 the base and tip, where the banding is interrupted. In two fully adult animals 

 there are only five, alternate, yellow and black bands, but the apical yellow band is 

 so broad that the tail is rich orange, while the hairs at the tip are almost entirely 

 yellow, or nearly white. I have examined a very large series of individuals of this 

 type, aU from a limited area, and the characters as just described are wonderfully 

 persistent, but they lead directly into the black backs by the not unfrequent occur- 

 rence of squirrels of this type with commencing indications of a. black back which in 

 others is still more defined until individuals of this fulvous phase are found which 

 have intensely black backs. The fulvous squirrels without black backs have gene- 

 rally white whiskers, but in a set of three selected without reference to the colour 

 of the whiskers, one — the young example with the ringed tail just described — has the 

 whiskers whoUy black, with the exception of three, short, white hairs on each side. 



In the generality of squirrels with black backs, the prevailing colour of the upper 

 fur is less fulvous than in the phase just described ; the chestnut of the under parts 

 is darker, and extends, in some, on to the under surface of the neck, while in others 

 that part is concolorous with the sides of the body, and the colour passes backwards 

 for a short way as a mesial Kne on to the chest, while in others it forms a mesial line 

 along the abdomen, and is punctulated like the sides. The colour of the head is 

 variable, in some rusty red, in others concolorous with the trunk. The tails also are 

 very variable, in some the hairs being broadly tipped with orange- yellow or pale 

 yellow, while in others, with the exception of the base, it is wholly black and unannu- 

 lated. In specimens with a cold grey-yellow, punctulated fur, the tail is yeUowish- 

 grey and black, interruptedly banded. In these squirrels the head is yellowish, and 

 the under surface of the trunk and the inside of the hmbs are deep, rich chestnut, 

 with a grizzled line over the chest. The S. hyperythrus, Blyth, is a phase near this, 

 but with no black on the back, and with the paler bands of the tail dark, rich 

 orange, instead of yellowish- grey, and the whiskers are wholly black. 



There can be no doubt whatever of the specific identity of these very differently 

 coloured squirrels, and that the two leading phases which I have described correspond 

 to the two phases manifested by >S'. caniceps, but their causation is quite unknown. 

 Of a series of eight specimens before me, four belong to animals in which no black 

 is developed on the back, and two of these are males and two females ; and, moreover, 

 two are fully adult. Another four belong to squirrels in which the black of the 

 back is strongly developed, and two are females, while one is a male and the sex of 

 the other is undetermined ; and these squirrels also are of different ages, as is evinced 

 by the condition of their skeletons which accompany their skins. One of the latter 

 series is younger than any of the four in which no black had developed on the back, 

 so that it would appear that age is not the determining cause of the presence or 

 absence of black in this species, and if so, it is also probable that it does not 

 influence the occurrence or absence of golden red on the back of S. caniceps. 

 Eurther, these eight squirrels tend to prove that the differences of coloration are 

 not sexual. 



