SCIURIDA—SPERMOPHILUS RICHARDSONI. 855 
GEOGRAPHICAL DISTRIBUTION.—The exact limits of the range of S. rich- 
ardsoni still remain unknown. Richardson gives its range as not extending 
beyond latitude 55°,* and as being a common inhabitant of the plains between 
the north and south branches of the Saskatchewan River. Along the forty- 
ninth parallel, it occurs, according to Dr. Coues, abundantly as far eastward as 
the Pembina Mountains,t and is common thence westward to the Rocky 
Mountains. It occurs southward along the James River to its sources, and 
probably throughout the more northern portions of the Territories to the 
westward.{ There are numerous specimens in the National Museum from 
various localities in Western Montana, Western Wyoming, Northern Utah, 
and Eastern Oregon. It is also reported by Richardson from the western 
slope of the Rocky Mountains north of the forty-ninth parallel. The most 
southern localities represented are the Laramie Plains and the Medicine Bow 
Mountains. 
Var. richardsoni is quite typically represented for some distancé south of 
the forty-ninth parallel, in Dakota and Montana; but more to the southward 
and westward, including Southern Montana, Western Wyoming, and thence 
westward, it gives place to var. townsendi. 
examples, an apparent objection to referring these names to any form of-S. richardsoni; but I find in 
many of the specimens of var. richardsoni that the ear is so shrivelled and rolled down as to appear to be 
merely a thickened rim rather than a distinct auricle; yet, in other respects, the specimens are not dif- 
ferent from those in which the ear is prominent. The specimens having the ears closely rolled would be 
naturally described as having the ear obsolete. 
* His reference in Franklin’s Journey (p. 662) to its occurrence on the “shores of the Arctic Sea” 
he afterward states to be incorrect.—(Twuna Bor.-Amer. vol. i, p. 165.) 
t Professor Baird refers to a “ very imperfect skin of a Spermophile” obtained “on an island in 
the Sault Ste. Marie, Michigan”, which he says “approaches Very closely to this species”, but adds that 
the specimen is not in a condition to admit of asatisfactory description. Its claws are referred to as being 
more Sciurine in character than those of S. richardsoni. An examination of this very poorly preserved 
and imperfect specimen satisfies me that it is referable to Sciurus hudsonius. It presents, however, 
an abnormal condition of pelage. 
di } Referring to the distribution of this species near the forty-ninth parallel, Dr. Coues observes :— 
“Speaking generally, they extend from the Red River of the North westward to the Rocky Mountains. 
Baird [see preceding foot-note] speaks of their occurrence in Michigan; but I have never seen any in 
Minnesota, nor indeed in the immediate valley of the Red River, even on the Dakota side. There the 
genus is represented by Spermophilus franklini and S. tridecemlineatus. But they appear in abundance just 
as soon as, in passing westward, we cross the low range of the Pembina Mountains, and strike perfect 
prairie, characterized by the presence of such birds as Sprague’s Lark and Baird’s and the Chestnut- 
collared Buntings. From this point they stretch clear away to the Rocky Mountains, subsiding only 
among the foot-hills of the main range, where the Pocket Gophers (species of Thomomys) begin to claim 
the soil: but a day’s march, indeed, from the rocky haunts of the Little Chief Hare (Lagomys princeps). 
The region of the Milk River and its tributaries, most of which, as well as the river itself, cross 49°, is 
their centre of abundance.”—( Amer. Nat. vol. ix, 1875, pp. 149, 150.) 
