SCIURIDiE— SCIURUS EUUSONIUS VAR. FREMONTI. 681 



respectively from Forts Steilacoom and Vancouver, which unquestionably rep- 

 resent var. douglassi. No. 4665 (from Fort Crook) is less fulvous than Nos. 

 3316 and 4664, while in No. 3847 this tint is barely traceable, thus forming 

 the passage to Nos. 3 848 and 3846, which are wholly white below. In No. 

 3847, the dorsal surface is quite strongly red, especially mesially, this tint 

 being continued into the tail ; but the lower parts show no trace of fulvous. 

 Other specimens have the middle of the back faintly rufous. In these speci- 

 mens, the pelage is fine and soft, and the gray of the upper surface is gener- 

 ally less fulvous than in Colorado specimens. 



Specimens from the Wind River Mountain region of Northwestern Wy- 

 oming present a peculiar combination of the characters of the three varieties 

 {fremonti, hudsonius, and richardsoni) whose habitats there meet, very few 

 of the specimens typically representing either variety, while not a few of 

 them are almost as well referable to one variety as to the other. As already 

 noticed, in the region of the Black Hills var. hudsonius loses much of its 

 redness; the dorsal band becomes less distinct; the middle of the tail is 

 paler; and the edging of the tail is yellowish-gray, instead of bright fulvous, 

 or yellowish-red, as is the case in eastern specimens. In specimens from 

 the sources of the Yellowstone River, particularly in those from the head of 

 the Gros Ventres Fork, the Geyser region of the Yellowstone, etc., we have 

 generally a strong approach to var. richardsoni, combined with some of the 

 features of hudsonius, as the indistinct darkening of the middle of the dorsal 

 region, the increase of black in the tail, and a deepening of the rufous of the 

 base of the tail-hairs to dull reddish-chestnut. In other specimens, the dor- 

 sal surface is like the dorsal surface in var. fremonti, with the tail presenting 

 a combination of the characters of vars. richardsoni and hudsonius. No. 9823, 

 from Yellowstone Lake, has the dorsal surface as in Black Hills specimens 

 of var. hudsonius, and also as in very fulvous specimens of var. fremonti, while 

 the rufous of the tail is that of var. richardsoni, but accompanied with much 

 less black than is seen in typical examples of the latter. Other specimens 

 have the color of the dorsal surface exactly as in average specimens of var. 

 fremonti, with the characters of the tail variously intermediate between vars. 

 hudsonius and richardsoni, perhaps on the whole more resembling hudsonius. 

 Wind River Valley specimens are much more reddish above, with a tendency 

 to a well defined dorsal band, while in some there is scarcely more black in 

 the tail than in average examples of var. hudsonius, the rufous of which, how- 



