MICROTUS. 185 



fi.—canescens. [.Vicrotits), Baikj-, Proc. Biol. Soc. Wash., 1898, 

 p. 87. 



Type locality. ConconuUy, Washington. 



Geogr. Distr. Northern Washington and southern British Co- 

 lumbia. 



God. Char. Similar to -1/. nanus, but paler. Skull: mastoid 

 breadth greater; audital bulla; larger; molar pattern as in J/, nanus; 

 hip glands conspicuous in adult males. 



Color. Above dark grayish; sides lighter gray; beneath white; 

 feet dark gray; tail above blackish; grayish beneath. 



.\fcasuri-nien/s. Total length, 149; tail vertebrae, 42; hind foot, 

 20. Skull: occipital condyles to anterior base of molars, 17.4; zygo- 

 matic breadth, 15: mastoid, 12.3; length of molar series, 63. 



265. canicaudus. [Microtus). Miller, Proc. Biol. Soc. Wash., 1S97, 



p. 67. 



Type locality. McCoy, Oregon. 



Geogr. Distr. Willamette Valley, Oregon, southern Washing- 

 ton on eastern slopes of the Cascade Mountains. 



Gcnl. Char. Size about as M. nanus, but more yellow. The 

 brain case is broader and deeper; audital bulhr flatter and more 

 round. 



Color. Above and sides umber brow-n mixed with black, darker 

 on head and paler on sides; beneath grayish white tinged with yel- 

 lowish: tail above whitish gray, beneath paler. Base of fur plum- 

 beous. 



Measurements. Average total length, 135; tail vertebrir, 33.7; 

 hind foot, 20. 



266. dutcheri. (.\ficrotus), Bailty, Proc. Biol. Soc. Wash., 1898, 



p. 85. 



Type toealily. Big Cottonwood Meadows, near Mt. Whitney, 

 California. 



Geogr. Distr. Inyo and Tulare counties, eastern California. 

 " Hudsonian zone of the southern Sierra Nevada." 



Genl. Char. Size small; tail short; ears small; hip glands pres- 

 ent in adult males. 



Color. Above dark bister, hairs tipped with brown; beneath 

 buffy brown; feet whitish; tail blackish above, whitish below. 



Measurements. Total length, 167; tail vertebra', 35; hind foot, 20. 



267. nevadensis. (Mierotus). Bailey, Proc. Biol. Soc. Wash., 1898, 



p. S6. 

 Type locality. Ash Meadows, Nye county, Nevada. 



