NORTH AMERICAN" RECENT MAMMALS. 419 



*Microtus richardsoni richardsoni — Continued. 



Range. — The typical form is known only from the vicinity of 

 Jasper House and Henry House, Alberta, Canada. To the 

 south it apparently grades into macropus in the Rocky Moun- 

 tains and arvicoloides in the Cascades. (Recorded from Moose 

 Pass, Alberta, by HoUister, Canadian Alpine Journal, Special 

 Number, p. 24, February 17, 1913.) 



t*Microtus richardsoni macropus (Merriam). 



1891. Arvicola {Mynomes) inacropus Merriam, North Amer. 



Fauna, No. 5, p. 60. July 30, 1891. 

 1900. Microtis richardsoni macropus Bailey, North Amer. 



Fauna, No. 17, p. 61. June 6, 1900. 

 Type Locality. — Pahsimeroi Mountains, Custer County, Idaho. 



Altitude, about 9,700 feet. 

 Range. — Boreal zone of the Rocky Mountains from the Wasatch 



north to Canada, of the Wind River Mountains of Wyoming, 



the Blue Mountains of Oregon, and most of the intermediate 



ranges. 



*Microtus richardsoni arvicoloides (Rhoads). 



1894. Aulacomys arvicoloides Rhoads, Amer. Nat., vol. 28, p. 182. 

 February, 1894. 



1895. Microtus principalis Rhoads, Amer. Nat., vol. 29, p. 940. 

 October, 1895. (Mount Baker Range, British Columbia, 

 Canada.) 



1900. Microtus richardsoni arvicoloides Bailey, North Amer. 



Fauna, No. 17, p. 62. June 6, 1900. 

 Type Locality. — Lake Keechelus, Kittitas County, Washington. 



Altitude, 8,000 feet. 

 Range. — Boreal zone of the Cascade Mountains, in Washington 



and Oregon. 



Subgenus PEDOMYS Baird. 



1857. Pedomys Baird, Mamm. N. Amer., p. 517. Type, Arvicola 

 austerus LeConte = Hypudseus ochrogaster Wagner. 



*Microtus ochrogaster (Wagner). 



1842. Hypudseus ochrogaster Wagner, Schreber's Saugthiere, 



Suppl., vol. 3, p. 592. 

 1885. Arvicola austerus True, Proc. U. S. Nat. Mus.,vol. 7 (1884) , 



p. 597. 1885. 

 1898. Microtus (Pedomys) ochrogaster Allen, Bull. Amer. Mus. 



Nat. Hist., vol. 10, p. 459. November 10, 1898. 

 1907. Microtus ochrogaster Osgood, Proc. Biol. Soc. Washington, 



vol. 20, p. 48. April 18, 1907. 

 Type Locality. — America. 

 Range. — Central part of Mississippi Valley from southern 



Wisconsin to southern Missouri and Fort Reno, Oklahoma, 



and west into eastern Nebraska and Kansas. 



