Specimens of E. a. luteiventris and E. umbrinus fremonti have been taken together at the same places.
In general, E. m. consobrinus occurs in open country and at the edges of forests, whereas E. u. fremonti occurs in the forest. E. a. luteiventris occurs in the intermediate habitat, that is to say, not far into the forest, and not so far out into the open as E. m. consobrinus.
Specimens examined.—Total number, 83.
Yellowstone Park: Unspecified, 2.
Park Co.: 31½ mi. N and 36 mi. W Cody, 6,900 ft., 6; 29 mi. N and 31 mi. W Cody, 7,200 ft., 1; 28 mi. N and 30 mi. W Cody, 7,200 ft., 1; 16¼ mi. N and 17 mi. W Cody, 5,625 ft., 3; 25 mi. S and 28 mi. W Cody, 6,350 ft., 2.
Teton Co.: Two Ocean Lake, 2 (1 FC); Whetstone Creek, 8 (MM); Emma Matilda Lake, 1 (FC); Pacific Creek Road, 2½ mi. E Moran, 1 (FC); Two Ocean Lake Road, 2 (FC); 2 mi. E Moran, 1 (FC); 2½ mi. E and 1/4 mi. N Moran, 6,230 ft., 8; Pacific Creek, 1 (MM); junction of Two Ocean Lake Road and U.S. Highway 187, 2 (FC); Signal Mountain Road, 1 (FC); Leigh Lake, 9 (MM); Indian Paint Brush Canyon, Teton Park, 1 (MM); Teton National Park, 3; 3 mi. E and 1/4 mi. S Moran, 6,200 ft., 1; 3¾ mi. E and 1 mi. S Moran, 6,200 ft., 8; 2½ mi. N and 3½ mi. E Moran, 7,225 ft., 1; Timbered Island, 6,750 ft., 4 mi. N Moose, 5; Bar BC Ranch, 6,500 ft., 2½ mi. NE Moose, 9; Grand Teton, 9,000 ft., Teton Park, 1 (MM); Upper Arizona Creek, Jackson, 1 (MM).
Lincoln Co.: 3 mi. N and 11 mi. E Alpine, 5,650 ft., 2.
Additional records (Howell 1929:69): Yellowstone Park: Mammoth Hot Springs; Roaring Mountain; Bunsen Peak; Yancey; Apollinaris Spring; Canyon; Yellowstone Lake; Upper Geyser Basin; Old Faithful. Park Co.: Near head of Clarks Fork; Pahaska, N Fork Shoshone River at Grinnell Creek; Valley. Teton Co.: Moran; Teton Mountains; Teton Pass. Lincoln Co.: Afton, Salt River Mountains; head of La Barge Creek, 9,100 ft.; Salt River Mountains, 10 mi. SE Afton. Sublette Co.: Merna; Stanley.
Diagnosis.—Size medium to large; general tone of upper parts Smoke Gray; dorsal stripes indistinct or obsolete; often brightly colored at base of tail; keel of baculum proportionally high, approximately 1⁄3 of length of tip; skull longer than 34.5 mm.