MAY, 1903. A LIST OF MAMMALS ELLIOT. 189 



difficulty any one experiences when endeavoring to distinguish the 

 closely allied races of this perplexing genus. 



Microtus townsendi. 



Microtus townsendi. (Bachm.), Jour. Acad. Nat. Scien., Phila., 

 1839, p. 60. Elliot, Syn. N. Am. Mamm., 1901, p. 190. 



Twenty-nine specimens: 20, Eureka, California; 8, Marshfield; 

 i, McCoy, Oregon. 



Mr. Heller says this species was "common about tide-water, with 

 habits very similar to those of the muskrat. They tunnel into the 

 dykes and river banks, building runways and holes which have an 

 entrance beneath the water like Fiber. Besides these tunnels about 

 banks, they construct runways through the grass in meadows like 

 other species of Microtus. Several were observed diving from their 

 slides along the banks of streams. Some were caught in traps set 

 beneath the water for Fiber. Grass is the only material I have seen 

 this species collect and carry into their nests." 



Microtus angusticeps. 



Microtus angusticeps. Bailey. Proc. Biol. Soc., Wash., 1898, p. 

 86. Elliot, Syn. N. Am. Mamm., 1901, p. 192. 



Forty specimens: 10, Requa; 10, Crescent City (topotypes), 

 California; 20, Goldbeach, Oregon. 



This vole Mr. Heller says was abundant everywhere near Crescent 

 City from swamps to grain-fields, replacing M. californicus^ which 

 extends no farther north on the coast than the Klamath River. 



B. CHILOTUS. 

 Microtus oregoni. 



Microtus oregoni. (Bachm.), Jour. Acad. Nat. Scien., Phila., 

 1839, p. 60.. Elliot, Syn. N. Am. Mamm., 1901, p. 200. 



Twenty-one examples: 10, Eureka; 2, Requa, California; 4, 

 Goldbeach; 5, Beaverton, Oregon. 



Two color phases are exhibited in this series, a dark phase (one 

 specimen from Goldbeach being almost black) and the usual red- 

 dish hue. 



FIBER. 

 Fiber occipitalis. 



Fiber occipitalis. Elliot, Pub. Field Columb. Mus., in, 1903, 

 p. 162, Zoology. 



Four specimens from Florence, Oregon. 



