Part 8

#Eutamias panamintinus# (Merriam)

Figure 16

Dorsal dark stripes reddish; size small to medium; skull of medium size; braincase flattened.

Baculum: Shaft thick; keel low, 1/3 of length of tip; base of keel 1/2 of length of tip; tip 52 per cent of length of shaft; angle formed by tip and shaft 110°; distal 2/3 of shaft moderately compressed laterally; base markedly widened; shaft short, 2.17 mm.

Differs from E. umbrinus and E. palmeri, in distal 2/3 (rather than 1/2) of shaft moderately compressed laterally; from E. bulleri, in keel smaller, shaft shorter, ridges on either side of tip distinct.

For comparisons with other species of chipmunks of western North America, see the accounts of those species.

The structure of the baculum most closely resembles that of E. speciosus and the geographic ranges of these two species are in juxtaposition.

Specimen examined: One from Coal Kilns, Panamint Mountains, Inyo Co., California (CN).

#Eutamias umbrinus# (J. A. Allen)

Figures 17-18

General tone of upper parts dark; size medium to large; skull of medium size; braincase narrowed.

Baculum: Shaft thick; keel low, 1/4 of length of tip; tip 36 to 50 per cent of length of shaft; angle formed by tip and shaft 100°; distal 1/2 of shaft markedly compressed laterally; base markedly widened; shaft short to medium, 2.51 to 3.03 mm.

Differs from E. bulleri, in shaft shorter, keel smaller, ridges on either side of tip distinct; distal 1/2 of shaft strongly compressed laterally. Does not differ from E. palmeri.

For comparisons with all other species of chipmunks of western North America, see the accounts of those species.

Specimens of E. umbrinus montanus from north-central Colorado have, in the past (Howell 1929:82), been referred to E. quadrivittatus quadrivittatus. In many features these two kinds of chipmunks resemble each other closely; their bacula, nevertheless, differ markedly (compare figs. 8-9 with 17-18).

Specimens examined: 25.

E. umbrinus umbrinus: Wyoming: Uinta Co.: 10 mi. S and 1 mi. W Robertson, 8,700 ft, 1. Utah: Uintah Co.: Paradise Park, 21 mi. W and 15 mi. N Vernal, 10,050 ft., 12.

E. u. adsitus: Utah: Beaver Co.: Britts Meadow, Beaver Range Mountains, 8,500 ft, 1 (BS). Wayne Co.: Donkey Lake, Boulder Mountain, 10,000 ft., 1 (UU). Garfield Co.: Wildcat R. S., Boulder Mountain, 8,700 ft., 1 (UU).

E. u. sedulus: Utah: Garfield Co.: Mount Ellen, Henry Mountains, 1 (BS).

E. u. inyoensis: California: Tulare Co.: Mount Whitney, head of Big Cottonwood Creek, 2 (BS). Nevada: Elko Co.: W side Ruby Lake, 3 mi. N Elko County Line, 1.

E. u. nevadensis: Nevada: Clark Co.: Sheep Mountains, 1 (MM).

E. u. fremonti: Wyoming: Sublette Co.: 31 mi. N Pinedale, 8,025 ft., 1; 19 mi. W and 2 mi. S Big Piney, 1.

E. u. montanus: Colorado: Boulder Co.: 3 mi. S Ward, 9,000 ft., 1; 1/2 mi. E and 3 mi. S Ward, 9,400 ft., 1.

#Eutamias palmeri# Merriam

Figures 17-18

General tone of upper parts grayish tawny; ocular stripe pale; skull, rostrum, nasals, and upper incisors shorter than in E. umbrinus.

Baculum: Indistinguishable from that of E. umbrinus. This supports the opinion of previous students that E. palmeri is a close relative of E. umbrinus which occurs immediately to the north and east. Intergradation does not occur between these two species, for, low-lying terrain, inhospitable to chipmunks, isolates E. palmeri from its relatives. (Verbal information from E. R. Hall.)

Specimen examined: One from Charleston Peak, 8,000 ft., Clear Creek Co., Nevada.