Vol. XI, pp. 67-68 ' April 21, 1897 



PROCEEDINGS 



OF THK 



BIOLOGICAL SOCIETY OF WASHINGTON 



DESCRIPTION OF A NEW VOLE FROM OREGON. 

 BY GERRIT S. MILLER, Jr. 



A small species of Microtus of tlie luiaas group, representetl by 

 twelve specimens from tlie Willamette Valley, Oregon,* may l)e 

 named and descriljed as follows : 



Microtus canicaudus ^p. iiov. 



Ti/pe from McCoy, Oregon. Adult J*, No. 75841, U. S. National Museum, 

 Biological Survey collection. Collected December 1, 1895, by B. J. Breth- 

 erton. Original No. 2119. 



General diameters. — Size and proportions a])Out as in Microtus nanus 

 (Merriam), but color yellower and less grizzled, and tail usually nearly 

 uniform grayisb above and below; skull broader tlian in M. nanus, witb 

 rounder audital buUte and differently sbaped bony palate. 



Odor. — Head, back, and sides umber-bi'own tbickly sprinkled with 

 blackish hairs, the ground color darker on head and paler on sides, where 

 it shades rather abruptly into color of belly ; ventral surface grayish 

 white, faintly marked with yellowish ; fur everywhere deep plumbeous 

 at base, this color showing through irregularly on belly and throat; tail 

 whitish gray, sliglitly paler below and darker at tip. 



The exact shade of brown varies, but it is always yellower than in 

 M. nanus, and seldom shows any approach to the peculiar grizzled ap- 

 pearance characteristic of the latter. The tail occasionally has a toler- 

 ably well-defined dark dorsal stripe, but in the great majority of speci- 

 mens (taken in March, April, October, November, and December) it is 

 scarcely visible. 



*Two from Beaverton (Nos. 371 and 372, IMiller collection), and ten 

 from McCoy (Nos. 75834-75842 and 75844, U. S. National Museum, Bio- 

 logical Survey collection), the latter kindly placed at my disposal by Dr. 

 C. Hart Merriam. 



U— Biol. Soc. Wash.. Voi,. XI, 1897 (67) 



