186 



MONOGRAPHS OF NORTH AMERICAN RODENTIA. 



magnis, paululum velle.re exstantibus; supra fulvo-badius, intime nigro permix- 

 tus, infra e griseo-brunneo albescens. 



Haritat. — Oregon and Washington Territories (Columbia River, July 

 21, lS,'5. r ), Toicnsend; the type. Puget Sound and Shoalwater Bay, Cooper 

 and Suckley. Cascade Mountains, Newberry). 



One of the larger meadow mice, 5 or 6 inches long, head l£, tail 2£, 

 hind fool 1, fore foot nearly h, ears nearly f high and as much or more wide, 

 projecting a little from the fur; color above blended yellowish-browu and 

 black ; below whitish, shaded with grayish-brown. 



* Measurements copied from Suckley, op. tit. ; specimen not seen. 



tThis specimen (since skinned out of alcohol) is about the longest-tailed American Arvicola we ever saw and has 

 given us some anxiety. It is small for lowmendii, with feet at a minimum and lacking a peculiar robustness those of town- 

 sendii generally show ; the ear likewise is remarkably small. But we can make no other disposition of the specimen. 



NOTE.— As will be seen from the figures, tuo Columbia River series, some of which, at least, appear full grown, are 

 not larger than ordinary riparius, and it is mainly on account of the great comparative length of the tail that we assign them 

 here. Tbey offer a gentle transition into ordinary riparius. No. 1275, as elsewhere noted, is still more doubtful ; it has the 

 tail as short as is usual in riparius, but tho feet beyond the maximum of ordinary riparius— exactly the reverse conditions of 

 the Columbia River series. 



Description (of No. tWs). — In form, this animal does not differ from 

 other species of this section of the genus; nearly the usual relative propor- 

 tions of head, body, tail, and feet being exhibited. The tail, however, will 

 certainly average longer than in riparius; for in specimens no larger than the 

 latter, the tail averages at or beyond a maximum of riparius. This length 



