SCIQRID^;— SPERMOrniLUS 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,! 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. J 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 distance 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. townseridi. 



examples, an apparent objection to referring these names to any form of <S. richardsoni ; but 1 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 arc 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. C621 to its occurrence on the " shores of the Arctic Sea" 

 be afterward states to be incorrect. — (Fauna Bor.-Amer. vol. i, p. 1C5.) 



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 a satisfactory 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 Hjciurtis hudsonius. It presents, however, 

 an abnormal condition of pelage. 



t Referring to the distribution of this species near tho forty-ninth parallel, Dr. Cones 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 tho immediate valley of tho Red River, even on tho Dakota side. There the 

 genus is represented by Spermojphilus franklini and S. Iridcccmlineatus. 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 tho 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 Thomovujs) begin to claim 

 the soil : but a day's march, indeed, from the rocky haunts of the Little Chief Hare (Lagomys princepa). 

 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. Aa(. vol. ix, 1875, pp. 149, 150.) 



