_Specimens examined._--Total 127, as follows: _Alaska_: N side Salcha River, 600 ft., 25 mi. S and 20 mi. E Fairbanks, 1. _Yukon Territory_: 6 mi. SW Kluane, 2550 ft., 2; McIntyre Creek, 2250 ft., 3 mi. NW Whitehorse, 10; ½ mi. W Whitehorse, 1; SW end Dezadeash Lake, 18; 1½ mi. S and 3 mi. E Dalton Post, 2500 ft., 24. _British Columbia_: Stonehouse Creek, 5½ mi. W jct. Stonehouse Creek and Kelsall River, 20; Hot Springs, 3 mi. WNW jct. Trout River and Liard River, 4; ¼ mi. S jct. Trout River and Liard River, 15; S side Toad River, 10 mi. S and 21 mi. E Muncho Lake, 27; SE end Muncho Lake, 4; Summit Pass, 4500 ft., 10 mi. S and 70 mi. W Fort Nelson, 1. _Remarks._--Specimens from 1½ miles south and 3 miles east of Dalton Post and from Dezadeash Lake in Yukon Territory and from Stonehouse Creek in British Columbia are referred to _M. l. vellerosus_ although in color of upper parts they show close relationship with _M. l. littoralis_. These specimens are less gray and more brown than specimens more typical of _M. l. vellerosus_ from the Liard River area. Alcorn found the long-tailed meadow mouse in widely separated areas. Most specimens were obtained in grassy situations near water or on moist ground. The single male from Summit Pass in British Columbia was taken above timberline. Microtus longicaudus littoralis Swarth Long-tailed Meadow Mouse _Microtus mordax littoralis_ Swarth, Proc. Biol. Soc. Washington, 46:209, October 26, 1933. (Type from Shakan, Prince of Wales Island, Alaska.) _Microtus longicaudus littoralis_ Goldman, Jour. Mamm., 19:491, November 14, 1938. _Specimens examined._--Total 29, as follows: _Alaska_: E side Chilkat River, 100 ft., 9 mi. W and 4 mi. N Haines, 9; 1 mi. S Haines, 5 ft., 20. _Remarks._--In comparison with the series of _M. l. vellerosus_ from the Liard River area, the long-tailed meadow mice from near Haines are more reddish brown, have a longer tail, and have a smaller skull with smaller auditory bullae. This subspecies is restricted to the coastal area, and as noted under the account of _M. l. vellerosus_, intergradation between these two forms occurs a relatively short distance inland. Microtus oeconomus macfarlani Merriam Tundra Mouse _Microtus macfarlani_ Merriam, Proc. Washington Acad. Sci., 2:24, March 14, 1900. (Type from Fort Anderson, Anderson River, Mackenzie district, Northwest Territories, Canada.) _Microtus oec[onomus] macfarlani_ Zimmerman, Archiv f. Naturgesch., 11:187, September 12, 1942.