MILLER AND REHN: NORTH AMERICAN MAMMALS. 127 
Type LOCALITY. — Pigeon Spring, Mount Magrucler, I^evada, 
near boundaiy between Inyo County, California, and Esmer¬ 
alda County, Nevada. 
Microtus pallidus (Merriam). 
1888. Arvicola {CJnlottis) pallidus Merriam, Anier. nat., 
XXII, p. 704. August, 1888. 
1896. Microtus p)(Alidus Miller, North Amer. fauna, no. 12, 
p. 50. July 23, 1896. 
Type locality. — Fort Buford, Howard County, North 
Dakota. 
Microtus pauperrimus (Cooper). 
1868. Arcicola pauperrima Cooper, Amer. nat., ii, p. 535. 
December, 1868. 
1896. M\icrotu^ pauperrimus Miller, North Amer. fauna, 
no. 12, p. 51. July 23, 1896. 
Type locality. — Plains of the Columbia, near the Snake 
River, southwestern Washington. 
Subgenus Chilotus Baird. 
1857. Chilotus Baird, Mamm. N. Amer., p. 516. Type.— 
Arvicola oregoni Bachman. 
* Microtus oregoni (Bachman). 
1839. Arvicola oregoni Bachman, Journ. acad. nat. sci. 
Phila., VIII, pt. I, p. 60. 
1885. Arvicola or eg onus True, Proc. U. S. nat. mus., vii 
(1884), p. 597. 1885. 
1896. Microtus oregoni Miller, North Amer. fauna, no. 12, 
p. 9. July 23, 1896. 
Type locality. — Astoria, Clatsop County, Oregon. 
Microtus serpens Merriam. 
1897. Microtus serpens Merriam, Proc. biol. soc. Washing¬ 
ton, XI, p. 75. April 21, 1897. 
Type locality. — Agassiz, British Columbia, Canada. 
