174 Vmversity of California PublicaHoiis in Zoology [Vol. 24 



species as Microtus admiraltiae, of Admiralty Island, does to M. drum- 

 mondi of the adjacent mainland. The two Microtus, however, are less 

 widely separated than the Evotomys have become. Further, it may 

 be assumed that Evotomys phaeus, of the Alaskan mainland south of 

 the habitat of wrangeli, is of a different line of descent, it differs so 

 markedly from both dawsoni and wrangeli in its combination of large 

 size, pale coloration, and long tail. Much remains to be learned regard- 

 ing the distribution and relationships of the red-backed mice of the 

 northwest. 



TABLE I 



Measurements in millimeters (average, minimum and maximum) of adult Evotomys 



wrangeli from Wrangeli, Alaska; measurements taken 



by Ernest P. Walker 



Total length Tail vertebrae Hind foot Ear 



10 adult males 141 (130-159) 35.7 (31-42) 18.2 (18-19) 11.8 (10-13) 



10 adult females 131.4 (127-152) 32.4 (28-40) 17.9 (17-18) 11.9 (10-13) 



Microtus drummondi (Audubon and Bachman). 

 Drummond Meadow Mouse 



Fifty -five specimens taken (nos. 30755-30809), from the following 

 points: Sawmill Lake, near Telegraph Creek, 16; Glenora, 20; Doch- 

 da-on Creek, 18 ; Sergief Island, 1. 



Around Telegraph Creek we found this species at but one place, in 

 the immediate vicinity of Sawmill Lake. Some parts of the lake shore 

 were grown with tall grass, partly flooded, and strewn with logs and 

 other drift. Here the Drummond meadow mice had their homes ; their 

 runways traversed the moss-grown logs, and, in the intervals between, 

 they evidently traveled through very deep water when necessary. 



