NORTH AMERICAN LAND MAMMALS. 219 



t*Microtus operarius operarius (Nelson) . 



1893. Arvicola operarius Nelson, Proc. Biol. Soc. Washington, 



vol. 8, p. 139. December 28, 1893. 

 1897. [Microtus] operarius Trovbssaut, Catal. Mamm. viv. foss., 



p. 564. 

 Type Locality. — St. Michael, Norton Sound, Alaska. 

 Range. — Barren grounds about Bristol Bay, St. Michael, andl 



Kowak River, Alaska. 



t*Microtus operarius endoecus Osgood. 



1909. Microtus operarius endcecus Osgood, North Amer. Fauna,' 



No. 30, p. 23. October 7, 1909. 

 Type Locality. — Mouth of Charlie Creek, Yukon River, about 

 50 miles above Circle, Alaska. 



t* Microtus macfarlani Merriam. 



1900. Microtus macfarlani Merriam, Proc. Washington Acad. 

 Sci., vol. 2, p. 24. March 14, 1900. 



Type Locality. — Fort Anderson, Anderson River, Mackenzie, 

 Canada. 



Range.— Tundra region of Arctic America, east of the Macken- 

 zie River. 



t*Microtus yakutatensis Merriam. 



1900. Microtus yaJcutatensis Merriam, Proc. Washington Acad. 



Sci., vol. 2, p. 22. March 14, 1900. 

 Type Locality. — North shore of Yakutat Bay, Alaska. 

 Range. — Mainland of Alaska from Glacier Bay to Prince Wil- 

 liam Sound. 



t*Microtus kadiacensis Merriam. 



1897. Microtus Icadiacensis Merriam, Proc. Biol. Soc. Wash- 

 ington, vol. 11, p. 222. July 15, 1897. 

 Type Locality. — Kodiak Island, Alaska. 

 Range. — Kjiown only from the type locality. 



t*Microtus unalascensis unalascensis Merriam. 



1897. Microtus unalascensis Merriam, Proc. Biol. Soc. Wash- 

 ington, vol. 11, p. 222. July 15, 1897. 

 Type Locality. — Unalaska, Alaska. 

 Range. — Island of Unalaska. 



t*Microtus unalascensis popofensis Merriam. 



1900. Microtus unalascensis popofensis Merriam, Proc. Wash- 

 ington Acad. Sci., vol. 2, p. 22. March 14, 1900. 

 Type Locality. — Popof Island, Shumagin Islands, Alaska. 

 Range. — Known only from Popof Island. 



