KANSAS. _Finney County_: 1 mi. S, 2 mi. E Garden City, 4. _Ford County_: 1/2 mi. NW Bellefont, 10; 6-1/4 mi. N Fowler, 2. _Grant County_: 2 mi. S, 9 mi. W Santanta, 1. _Kearney County_: 3-1/2 mi. N, 4 mi. E Lakin, 4. _Meade County_: within 2-1/2 mi. Fowler, 10; Meade County State Park, 14 mi. SW Meade, 48; 17 mi. SW Meade, 5. _Morton County_: 7-1/2 mi. S Richfield, 4; 8 mi. N Elkhart, 1; 7-1/2 mi. N, 1-1/2 mi. W Elkhart, 2. _Seward County_: 3 mi. NE Liberal, 1. _Stanton County_: 1 mi. N, 6-7-1/2 mi. W Manter, 2; dam of Lake Stanton, 1. NEW MEXICO. _Bernalillo County_: 6-1/2 mi. E Alameda, 11; 5 mi. W Albuquerque, 3. _Catron County_: 1 mi. NE Apache Creek, 4; Apache Creek, 2. _Guadalupe County_: 4 mi. SW Santa Rosa, 4700 ft., 10. _McKinley County_: Upper Nutria, 7200 ft., 2. _Rio Arriba County_: 4 mi. N El Rito, 1; 1 mi. SE El Rito, 1. _Sandoval County_: 3 mi. N La Cueva Rec. Area, 1. _San Juan County_: 2 mi. N La Plata, 15. _Santa Fe County_: 1 mi. W Santa Fe Municipal Airport, 1; La Bajada Grade, 20 mi. W Santa Fe, 1. _Socorro County_: 2 mi. S San Antonio, 4. OKLAHOMA. _Beaver County_: 7 mi. S Turpin, 1. _Texas County_: 3-1/2 mi. SW Optima, 8. TEXAS. _Hansford County_: 10 mi. S, 1 mi. W Gruver, 2. _Hutchinson County_: 9 mi. E Stinnett, 1 (TU). _Reithrodontomys megalotis dychei_ J. A. Allen _Reithrodontomys dychei_ J. A. Allen, Bull. Amer. Mus. Nat. Hist., 7:120, May 21, 1895 (type locality, Lawrence, Douglas Co., Kansas). _Reithrodontomys megalotis dychei_, A. H. Howell, N. Amer. Fauna, 36:30, June 5, 1914. _Reithrodontomys dychei nebrascensis_ J. A. Allen, Bull. Amer. Mus. Nat. Hist., 7:122, May 21, 1895 (type locality, Kennedy, Cherry Co., Nebraska). _Distribution._--Southwestern Wisconsin, southern Minnesota, northwestern Illinois, Iowa, Missouri and northwestern Arkansas, west through Kansas (except southwestern part), Nebraska and the Dakotas to the foothills of the Rocky Mountains from central Colorado to southeastern Alberta. _External measurements._--Average and extremes of 17 adults (11 males, 6 females) from Douglas County, Kansas, are: total length, 134.2 (115-151); length of tail-vertebrae, 64.2 (59-72); length of hind foot, 16.7 (15-18); length of ear from notch, 13.4 (12-15); tail averaging 91.7 per cent of length of body. Corresponding measurements of 20 adults (14 males, 6 females) from Cherry County, Nebraska, are: 135.3 (122-155); 62.9 (56-72); 17.5 (17-18); 13.0 (12-14); tail averaging 86.9 per cent of length of body. For cranial measurements see Tables 1 and 2.