NORTH AMERICAN LAND MAMMALS. 221 



Microtus townsendii — Continued. 



Type Locality.— Columbia River; according to Bailey (North 



Amer. Fauna, No. 17, p. 46, June 6, 1900), near mouth of 



Willamette, on or near Wappatoo (or Sauvie) Island. 

 Range. — Low country west of the Cascades, from Port Moody, 



British Columbia, south to the Willamette Valley and to 



Yaquina Bay, Oregon, in transition zone. 



*Microtus tetramerus (Rhoads). 



1894. Arvicola {Tetramerodon) tetramerus Rhoads, Proc. Acad. 

 Nat. Sci. Philadelphia, p. 283. October 23, 1894. 



1900. Microtus tetramerus Bailey, North Amer. Fauna, No. 17, 



p. 47. June 6, 1900. 

 Type Locality. — Beacon Hill Park, Victoria, Vancouver Island, 



British Columbia, Canada. 

 Range. — Southern end of Vancouver Island. 



t*Microtus longicaudus (Merriam). 



1888. Arvicola {Mynomes) longicaudus Merriam, Amer. Nat. 

 vol. 22, p. 934. October, 1888. 



1895. Microtus ( Mynomes) longicaudus Allen, Bull. Amer. Mus. 

 Nat. Hist., vol. 7, p. 266. August 21, 1895. 



Type Locality. — Custer, Black Hills, Custer County, South 



Dakota. Altitude, 5,500 feet. 

 Range. — Boreal cap of the Black Hills and down some of the 



cold streams well into the transition zone. 



t*Microtus mordax mordax (Merriam). 



1891. Arvicola (Myomes) mortZax Merriam, North Amer. Fauna, 

 No. 5, p. 61. July 30, 1891. 



1897. [Microtus] mordax Trouessart, Catal. Mamm. viv. foss., 

 p. 564. 



1899. Microtus vellerosus Allen, Bull. Amer. Mus. Nat. Hist., 

 vol. 12, p. 7. March 4, 1899. (Upper Liard River, British 

 Columbia.) 



1899. Microtus cautus Allen, Bull. Amer. Mus. Nat. Hist., 

 vol. 12, p. 7. March 4, 1899. (Hells Gate, Liard River, 

 British Columbia.) 



Type Locality. — Sawtooth (or Alturas) Lake, east base of Saw- 

 tooth Mountains, Idaho. Altitude, 7,200 feet. 



Range. — Rocky Mountains and outlying ranges from latitude 

 60° to northern New Mexico, and south in the Cascades and 

 Sierra Nevada as far as Kaweah and Kern Rivers, CaUfornia. 

 In the Cascades mainly confined to the east slope, but extend- 

 ing west to the Siskiyous, in southern Oregon, and Salmon and 

 Trinity Mountains in northern California. Found in most of 

 the isolated ranges of eastern Oregon and northern and central 

 Nevada. Common in Canadian and Hudsonian zones. 



