274 U. 8. P. R. R. EXP. AND SURVEYS—ZOOLOGY—GENERAL REPORT. 
of this line is tinged with rusty. There isa light ring around the eye, and the sides of the 
nose are of a pale rusty. 
The hairs of the tail are long and coarse, scarcely distichous. At the extremity of the tail 
they are glossy black throughout, or with a slight base of chestnut; on the rest of the tail 
above they are dark plumbeous at the base, then dark chestnut to beyond the middle; then 
glossy black to near the tip, which is pale rusty, the latter increasing in extent towards the 
base of the tail. Beneath, the hairs are several times annulated with black and pale rusty for 
more than half their length; then glossy black to near the tip. 
According to Dr. Bachman it would appear that S. richardsonii is about the size of the striped 
squirrel, (Zamias striatus,) has less of reddish brown than in S. hudsonius, being even rusty 
gray. These specimens, on the contrary, are larger than S. hudsonius, and the upper parts are 
deeper reddish brown than in this species. They agree in the colors of the under parts and 
the dark line on the sides, as well as in the peculiar color of the tail. The feet appear smaller 
too. The description of the ‘‘small brown squirrel’’ of Lewis and Clark, referred to as belonging 
to this species, suits better S. douglassii, especially in respect to the ferruginous belly.+ 
This squirrel appears to be confined to the region between the main chain of the Rocky Moun- 
tains and the Cascade range. Its northern and southern limits are not ascertained. 
The Sciwrus lanuginosus of Bachman, as far as I can judge from examining. the original 
specimen brought by Townsend, is a partly albino and boreal variety of Sciwrus richardsonii. 
It is of the same size, and the tail presents the same peculiarly cylindrical tail. The fur is 
very soft and full, the sole, from heel to bases of toes, densely hairy. The muzzle, sides of face, 
and under parts are white; the sides mottled silver gray; the back with a wash of rufous. 
There is no distinct annulation on the tail, though the hairs generally are light gray at the 
roots, then broadly pale rufous, then dark brown, and finally tipped with lighter brown or gray. 
There is nothing in the color to militate against the supposition that this is the same with S. 
richardsonii, and the white head and lighter colors generally furnish strong confirmation of the 
idea that the color has been influenced by temperature, latitude, or other causes. Asis well 
known, North America has no species in which a head lighter than the body is a permanent 
characteristic. The peculiarly cylindrical tail is a strong point in the resemblance. It is 
barely possible that it may more properly be referrible to S. douglassii. 
The specimen is described by Bachman as coming from Sitka; it is, however, labelled 
‘* Columbia river, November 13, 1834,’’ most probably erroneously. 
List of specimens. : 
Cataloy’e Correspond’ g Locality. When Whence obtained. | Original Collected by— 
number. | No. of skull. collected. number. 
| 
——}- + SEE — 
214? | 1185 St. Mary’s Mis’n, R. Mts.| Oct. 1,1853 | Goy. I. I. Stevens - 3 Dr. G. Suckley -- 
7 Sn es 2 Deak cee (NR eae C eee ee eee Posse -ncees}s-5c.)- “2 |-sdos- sp iceeees do: 3-4-5 -- 
213 1184 Rocky Mountains ..----|--<-.---2--- se CLG Se 5 a NER Pa al | a a MO... aa tes 
I a os a dos--.-sia0+se2e|3 ee ene Beer Gore. coo) I ee eee do--—-<4== 
217 Fer as eoeoK | Spokane Plain, W. T-.--| Oct.30, 1853 |..__-- GGves pase = 10 Dr. J. G. Cooper. 
. | 
! Since writing this description I have examined the original specimen collected by Townsend and described by Dr. Bachman, 
now in the collection of the Philadelphia Academy. It is undoubtedly a quite immature animal, of the same species with the 
subject of the present article, 
2 Length, 9.00; tail, vertebre, 6.00; hairs, 8.00; ear, 0.50; hind foot, 1.83. 
