MICROTUS. 187 



Color. Above buff\- gray, beneath whitish. Tail, dull grayish, 

 feet gray. 



Measurements. Total length, average of four adults, 163; tail 

 vertebrs, 55; hind foot, 21.5. 



269. edax. (Arrico/a), Le Conte, Proc. Acad. Nat. Scicn. Phil., 1853, 



p. 405. 



Type locality. Vicinity of San Francisco, California. 



Geogr. Distr. Western and southern California. 



Genl. Char. Ears large; tail two-fifths the length of head and 

 body; plantar tubercles large; soles haired from heel to first tubercle. 



Color. Above pale yellowish brown thinlj- mixed with black; 

 sides paler; beneath soiled grayish white. Tail, brown above, dull 

 white beneath. 



.Miasurrments. Total length, 217; tail vertebrx', 73; hind foot, 25. 



270. scirpensis. (Microtis), Bailey, N. Am. Faun., igoo, No. 17, 



p. 38. 



Ty/>e locality. Amargosa Rivtr, Inyo Count)', California. 



Geogr. Distr. Known only from the type localit)-. 



Genl. Char. Similar to ^f. eda.x ; colors paler; middle upper 

 molar with rounded open or closed posterior loop. 



Color. Above dark buffy graj'; beneath smoky gray. Tail, 

 brown above, grayish beneath; feet brownish gray. 



.'^[easuremcnts. Total length, 210; tail vertebra-, 67; hind foot, 25. 



271. operarius. {Arvicola), Nelson, Proc. Biol. Soc. Wash., 1893, 



p. 139. 



Type locality. St. Michaels, Norton Sound, Alaska. 



Geogr. Distr. Coast tundras of Bering Sea from Cape Van- 

 couver to Bering Straits, including Nelson, St. Michaels and Stew- 

 art Islands; Alaska eastward to Anderson River. 



Genl. Char. Size small; tail one-third the length of head and 

 body; color pale. 



Color. Above pale fulvous or fawn faintly lined with black; 

 sides paler; beneath grayish white. Tail, above dark brown, beneath 

 white. Feet whitish. 



Measurements. Total length, 104.5: tail vertebra-, 25.2; hind 

 foot, 17.9; ear, 9.8. Juv? 



272. macfarlani. {.Microtia), Merr., Proc. W^ash. Acad. Scien., 



1900, p. 25. 

 Type locality. Fort Anderson, north of Great Bear Lake, Arctic 



America. 

 Geogr. Distr. Arctic America east of the Mackenzie River. 



