MILLER AND REHN: NORTH AMERICAN MAMMALS. 127 



TYPE LOCALITY. Pigeon Spring, Mount Magruder, Nevada, 

 near boundary between Inyo County, California, and Esmer- 

 alda County, Nevada. 



Microtus pallidus (Merriam). 



1888. Arvicola (Chilotus) pallidus MERRIAM, Amer. nat., 



xxn, p. 704. August, 1888. 

 1896. Microtus pallidus MILLER, North Amer. fauna, no. 12, 



p. 50. July 23, 1896. 

 TYPE LOCALITY. Fort Buford, Howard County, North 



Dakota. 



Microtus pauperrimus (Cooper). 



1868. Arvicola pauperrima COOPER, Amer. nat., n, p. 535. 



December, 1868. 

 1896. M\icrotus\ 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., vin, pt. i, p. 60. 



1885. Arvicola oregonus TRUE, Proc. IT. S. nat. mus., vn 

 (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. 



