Eutamias umbrinus (J. A. Allen)
_Diagnosis._--Size large; general tone of upper parts dark; base of baculum widened; outermost dorsal dark stripe barely discernible or lacking; skull rarely shorter than 34.0 mm.
_Comparisons._--For comparisons with the other species of _Eutamias_ in Wyoming, see the accounts of _E. minimus_, _E.
amoenus_, and _E. dorsalis_.
_Remarks._--_E. umbrinus_ is the largest of the species of _Eutamias_ occurring in Wyoming. This species usually occurs in the Canadian and Hudsonian life-zones in the mountains of northwestern, southwestern, and south-central Wyoming.
Eutamias umbrinus umbrinus (J. A. Allen)
_Tamias umbrinus_ J. A. Allen, Bull. Amer. Mus. Nat. Hist. 3:96, June, 1890.
_Eutamias umbrinus_, Miller and Rehn, Proc. Boston Soc. Nat. Hist., 30:45, December 27, 1901.
_Type._--Male, adult, skull and skin, No. 186463 (NM); from Blacks Fork, about 9,500 ft., Uinta Mountains, Summit County, Utah; obtained on September 19, 1888, by Vernon Bailey; original No. 228.
_Diagnosis._--Size medium; over-all tone of upper parts dark and shadowy; skull smallest of this species in Wyoming.
_Description._--_Color pattern_: Crown Pale Smoke Gray; facial stripes Fuscous Black or Snuff-Brown; ears Fuscous Black; posterior margin of ear and postauricular patch grayish white; median dorsal dark stripe black with Sayal Brown along margins; lateral pair of dorsal dark stripes Fuscous Black mixed with Sayal Brown, or entirely Sayal Brown; outermost pair of dorsal dark stripes Sayal Brown mixed with Fuscous Black or lacking; sides Sayal Brown mixed with Cinnamon; rump and thighs Sayal Brown mixed with Smoke Gray; antipalmar and antiplantar surfaces of feet Cinnamon Buff; underside of tail Ochraceous Tawny or Sayal Brown, with Fuscous Black around margin and Pinkish Buff around outermost edge; underparts creamy white with dark gray underfur. _Skull_: Smooth and rounded; braincase inflated; zygomata strong. _Baculum_: Broadened at base; shaft tapers rapidly to tip.
_Comparisons._--From _E. u. fremonti_, the subspecies from the north in the mountains of northwestern Wyoming, _E. u. umbrinus_ differs in: Over-all tone of upper parts darker; sides lighter; skull smaller. From _E. u. monta.n.u.s_, the subspecies from the Medicine Bow Range of south-central Wyoming, _E. u. umbrinus_ differs in: Over-all tone of upper parts darker; sides darker; skull smaller.
_Remarks._--This subspecies occurs only in the foothills of the Uinta Mountains in the southern part of Uinta County. These "foothills" are well-timbered and at an alt.i.tude of 7,000 feet and higher.
_Specimens examined._--Total number, 23.
_Uinta Co._: 9 mi. S Robertson, 8,000 ft, 15; 10 mi. S and 1 mi. W Robertson, 8,700 ft., 5; 11-1/2 mi. S and 2 mi. E Robertson, 9,200 ft., 1; 2 mi. E and 12 mi. S Robertson, Ashley Nat. Forest, 1; 13 mi. S and 2 mi. E Robertson, 9,200 ft., 1.
_Additional records_ (Howell 1929:95): _Uinta Co._: Henry Fork, 5 mi. W Lone Tree; Lone Tree.
Eutamias umbrinus fremonti White
_Eutamias umbrinus fremonti_ White, Univ. Kansas Publ., Mus. Nat.
Hist. 5:575, December 1, 1953.
_Type._--Male, adult, skull, skin, and baculum, No. 41790 (KU); from 31 mi. N Pinedale, 8,025 ft., Sublette County, Wyoming; obtained on July 8, 1951, by Rollin H. Baker; original No. 1596.
_Diagnosis._--Size large; over-all tone of upper parts dark; lower tooth-row longest of this species in Wyoming.
_Description._--_Color pattern_: Crown Cinnamon Buff mixed with gray; upper facial stripe Sepia; ocular stripe Chaetura-Drab; submalar stripe Fuscous Black mixed with Sayal Brown; ears black; anterior margin of ear Mars Yellow; posterior margin of ear grayish white; hairs inside posterior part of pinna Dresden Brown; postauricular patch Pale Smoke Gray; median dorsal dark stripe black; lateral dorsal dark stripes black mixed with Sayal Brown; outermost dorsal dark stripes Buckhorn Brown mixed with black or sometimes absent; median pair of dorsal light stripes grayish mixed with Buckhorn Brown; outer pair of dorsal light stripes creamy white; sides Buckhorn Brown; rump and thighs Pale Smoke Gray mixed with Saccardo"s Umber; dorsal surface of tail black mixed with Buckhorn Brown; ventral surface of tail Sayal Brown, with Fuscous Black around margin and white or Light Buff around outermost edge; antipalmar and antiplantar surfaces of feet Warm Buff; underparts creamy white with dark underfur. _Skull_: Large; zygomata strong and arched; braincase well inflated. _Baculum_: Broad at base; shaft tapers sharply to tip.
_Comparisons._--From _E. u. monta.n.u.s_, the subspecies from the Medicine Bow Range of south-central Wyoming, _E. u. fremonti_ differs in: Over-all tone of upper parts darker; underside of tail darker; feet darker; sides darker.
For comparisons with _E. u. umbrinus_ see the account of that subspecies.
_Remarks._--This subspecies normally occurs in the forest as do the other subspecies of _E. umbrinus_ in Wyoming. A single specimen taken at 12 mi. N and 3 mi. W Shoshoni, Fremont County, is the exception which probably indicates that _E. umbrinus_ does occur outside of its normal habitat and that gene-flow exists between the subspecies of this species.
_Specimens examined._--Total number, 53.
_Yellowstone Park_: Unspecified, 2.
_Park Co._: Beartooth Lake, 1 (BS); 16-1/4 mi. N and 17 mi. W Cody, 5,625 ft., 2.
_Teton Co._: 1 mi. E and 1/4 mi. N Togwotee Pa.s.s, 9,800 ft., 2; Amphitheater Lake, Teton Park, 1 (MM); Flat Creek, 4 (MM); head of Cache Creek, 4 (MM); Jackson, Upper Arizona Creek, 2 (MM); Flat Creek-Granite Creek divide, 6 (MM); Flat Creek Pa.s.s, 1 (MM); Flat Creek-Gravel Creek divide, 2 (MM).
_Lincoln Co._: La Barge Creek, near source, 9,000 ft., 1 (BS).
_Fremont Co._: Togwotee Pa.s.s, 12 (FC); 12 mi. N and 3 mi. W Shoshoni, 4,650 ft, 1; Mosquito Park R.S., 9,500 ft., 17-1/2 mi. W and 2-1/2 mi. N Lander, 1; 17 mi. S and 6-1/2 mi. W Lander, 8,450 ft., 3.
_Sublette Co._: 31 mi. N Pinedale, 8,025 ft., 1; W side Barbara Lake, 10,300 ft., 8 mi. S and 3 mi. W Fremont Peak, 4; 19 mi. W and 2 mi. S Big Piney, 7,700 ft., 5.
_Additional records_ (Howell 1929:95): _Park Co._: Near head of Clark Fork; Whirlwind Peak near Pahaska, N Fork Shoshone River; Valley, Shoshone Mountains; Needle Mountain. _Teton Co._: Teton Mountains, S Moose Creek. _Lincoln Co._: Salt River Mountains.
_Sublette Co._: Gros Ventre Range, 12 mi. NW Kendall; Merna; 8 mi.
W Stanley; Big Sandy. _Fremont Co._: Jackey"s Creek, 4 mi. SW Dubois; Bull Lake, Wind River Mountains; Lake Fork, Wind River Mountains; Fremont Peak.
Eutamias umbrinus monta.n.u.s White
_Eutamias umbrinus monta.n.u.s_ White, Univ. Kansas Publ. Mus. Nat.
Hist. 5:576, December 1, 1953.
_Type._--Male, adult, skull, skin, and baculum; 20105 (KU); from 1/2 mi. E and 3 mi. S Ward, 9,400 ft., Boulder County, Colorado; obtained on August 1, 1947, by E. L. c.o.c.krum; original No. 721.
_Diagnosis._--Size large; over-all tone of upper parts light; sides light.
_Description._--_Color pattern_: Crown Raw Sienna mixed with gray; upper facial stripe and ocular stripe black mixed with Sepia; submalar stripe Snuff-Brown mixed with black; ear black or Sepia; anterior margin of ear Ochraceous Tawny; posterior margin of ear and postauricular patch grayish white; hairs inside posterior part of pinna Cinnamon Buff; median dorsal dark stripe black with Sayal Brown along margins; lateral pair of dorsal dark stripes black mixed with Sayal Brown; outermost pair of dorsal dark stripes Sayal Brown mixed with black or sometimes lacking; median pair of dorsal light stripes Pale Smoke Gray mixed with Clay Color; outer pair of dorsal light stripes creamy white; sides Clay Color; rump and thighs Neutral Gray; dorsal surface of tail black mixed with Cinnamon Buff; ventral surface of tail Ochraceous Tawny, with black along margin and Cinnamon Buff or Ochraceous Tawny along outermost edge; antipalmar and antiplantar surfaces of feet Cinnamon Buff; underparts creamy white with dark underfur. _Skull_: Large; zygomata strong and arched; braincase well inflated. _Baculum_: Broad at base; shaft tapers sharply to tip.
_Comparisons._--For comparisons with _E. u. umbrinus_ and _E. u.
fremonti_, see the accounts of those subspecies.
_Remarks._--Although in Wyoming this subspecies is known only from the Medicine Bow Range, one would expect to find it occurring in the Snowy Range and the Laramie Range as well, since there seems to be suitable habitat for this subspecies in those mountain ranges.
_Specimens examined._--Total number, 3.
_Albany Co._: 8 mi. ESE Browns Peak, 10,000 ft., 2; 3-1/2 mi. S Wood"s Landing, 1.
REVIEW AND CONCLUSIONS
_Eutamias minimus_ in Wyoming is divisible into two size-groups of subspecies; the smaller size-group (_E. m. minimus_ and _E. m.
consobrinus_), which occurs in the western part of the State, is significantly smaller, in measurements of the skull and baculum, than the larger size-group (_E. m. pallidas_, _E. m. confinis_, _E. m.
silvaticus_, and _E. m. operarius_) which occurs in the eastern part of the State.
Although all the six subspecies of _E. minimus_ in Wyoming can be differentiated from one another by color pattern, this species cannot be divided, by means of color pattern, into two groups, comparable in geographic range, to the two size-groups that were established above on the basis of variations in the skull and baculum.
Thus, the subspecies of _E. minimus_ are morphologically differentiated at two distinct levels; one level is based on differences in the skull and baculum, while the other is based on differences in color.