582 U. S. NATIONAL MUSEUM BULLETIN 205 



1920. Microtus oregoni bairdi Taylor, Journ. Mamm., vol. 1, No. 4, p. 180, 

 Aug. 24, 1920. 



Type Locality. — Glacier Peak, Crater Lake, Klamath County, Oreg. Altitude, 

 7,800 feet. Range. — Known only from type locality on an open timberline 

 ridge northwest of Crater Lake (V. Bailey, North Amer. Fauna No. 55 (June), 

 p. 213, Aug. 29, 1936) and Beswick, Siskiyou County, Calif. (Taylor, loc. cit.). 



Microtus oregoni adocetus Merriamf * 



1908. Microtus oregoni adocetus Merriam, Proc. Biol. Soc. Washington, 

 vol. 21, p. 145, June 9, 1908. 



Type Locality. — South Yolla Bolly Mountain [2 miles south of], Tehama 

 County, Calif. Altitude, 7,500 feet. Range. — Region of type locality in Tehama 

 and Trinity Counties, Calif., northwest to South Fork Mountain, Humboldt 

 County, Calif.; thence northward to Medford, Jackson County, Oreg.; zonal 

 range, Canadian, Transition and Upper Sonoran (Hatfield and Hooper, Murrelet, 

 vol. 16, No. 2, p. 34, May 1935) . 



Microtus oregoni serpens Merriamf* 



1897. Microtus serpens Merriam, Proc. Biol. Soc. Washington, vol. 11, p. 75, 

 Apr. 21, 1897. 



1920. M[icrotus] o[regoni] serpens Taylor, Journ. Mamm., vol. 1, No. 4, p. 

 180, Aug. 24, 1920. 



Type Locality. — Agassiz, British Columbia, Canada. Range. — Low country 

 of southwestern British Columbia; recorded from Agassiz, Chilliwack, Hunting- 

 ton, Langley, Port Moody, Sumas, Thurston's, and Vancouver (Anderson, Nat. 

 Mus. Canada Bull. 102 (1946), p. 162, Jan. 24, 1947) . Specimens from north- 

 western Washington regarded as oregoni (Dalquest, Univ. Kansas Publ. Mus. Nat. 

 Hist., vol. 2, p. 358, Apr. 9, 1948) . 



Subgenus AULACOMYS Rhoads 



1894. Aulacomys Rhoads, Amer. Nat., vol. 28, p. 182, February 1894. (Type, 

 Aulacomys arvicoloides Rhoads.) 



Microtus richardsoni richardsoni (DeKay) * 



1842. A[rvicola] richardsoni DeKay, Zoology of New York . . ., vol. 1, pt. 1 



(Mammalia), p. 91 (in [New York State], Natural history of New York). 

 1894. Aulacomys richardsoni Rhoads, Proc. Acad. Nat. Sci. Philadelphia, vol. 



46, p. 288, Oct. 23, 1894. 

 1897. [Microtus] richardsoni Trouessart, Catalogus Mammalium . . ., fasc. 



3, p. 565. 

 Type Locality. — "Near the foot of the Rocky Mountains." According to 

 V. Bailey (North Amer. Fauna No. 17, p. 60, June 6, 1900) the type was collected 

 by Drummond in the vicinity of Jasper House, Alberta, Canada. Range. — High 

 altitudes in Alberta from Waterton Lakes National Park north at least to Jasper 

 National Park in Rocky Mountains (Anderson, Nat. Mus. Canada Bull. 102 

 ( 1946) , p. 162, Jan. 24, 1947) . 



Microtus richardsoni arvicoloides (Rhoads) * 



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

 1894. (Regarded as identical with richardsoni by Anderson and Rand, 



