Chapter I

A New Chipmunk (Genus Eutamias) from the Black Hills

BY JOHN A. WHITE

University of Kansas Publications Museum of Natural History

Volume 5, No. 19, pp. 259-262 April 10, 1952

University of Kansas LAWRENCE 1952

UNIVERSITY OF KANSAS PUBLICATIONS, MUSEUM OF NATURAL HISTORY

Editors: E. Raymond Hall, Chairman, A. Byron Leonard, Edward H. Taylor, Robert W. Wilson

Volume 5, No. 19, pp. 259-262 April 10, 1952

UNIVERSITY OF KANSAS Lawrence, Kansas

PRINTED BY FERD VOILAND, JR., STATE PRINTER TOPEKA, KANSAS 1952

* * * * *

A New Chipmunk (Genus Eutamias) from the Black Hills

BY JOHN A. WHITE

Study of the chipmunks from the eastern Rocky Mountains and Great Plains reveals that the chipmunks from northeastern Wyoming and from South Dakota which Howell (N. Amer. Fauna, 52:55, November 30, 1929) referred to _Eutamias minimus borealis_ actually belong to a heretofore unnamed subspecies which may be named and described as follows:

#Eutamias minimus silvaticus# new subspecies

_Type._--Female, adult, skull and skin, No. 20050 Mus. Nat. Hist.,
Univ. Kansas; from 3 mi. NW Sundance, 5900 ft., Crook County,
Wyoming; obtained on July 4, 1947, by H. W. Setzer; original No.
1692.

_Range._--Bear Lodge Mountains in northeastern Wyoming and the
Black Hills of South Dakota.

_Diagnosis._--Size large (see measurements); general tone of
upper parts drab; sides Ochraceous Buff (capitalized terms are of
Ridgway, Color Standards and Color Nomenclature, Washington, D. C.,
1912); lateral stripes Fuscus Black washed with Ochraceous Tawny;
ventral side of tail near (14' _h_) Ochraceous Orange and fringed
with black.

_Comparisons._--From _Eutamias minimus pallidus_ (specimens from
Buffalo in Johnson County, Ivy Creek, Rockypoint, Middle Butte, and
South Butte in Campbell County, all in Wyoming, and Harrison, Sioux
County, Nebraska), the subspecies to the southward, westward, and
northward, _E. m. silvaticus_ differs in: General tone of upper
parts markedly darker, more reddish and less grayish; dorsal
stripes darker; crown markedly darker. External measurements, and
measurements and characters of the skull of the two subspecies,
do not differ significantly. Unless otherwise specified all
comparative material is in the Museum of Natural History of the
University of Kansas.

From _Eutamias minimus cacodemus_ (topotypes in the United States
National Museum), the subspecies to the southeastward, _E. m.
silvaticus_ differs in the same manner in which it differs from _E.
m. pallidus_, but the degree of difference is greater because _E.
m. cacodemus_ is even paler than _E. m. pallidus_.

From _Eutamias minimus confinis_ (specimens from 17-1/2 mi. E and
4-1/2 mi. S Shell, 8500 ft., Big Horn County, Wyoming), _E. m.
silvaticus_ differs in: General tone of upper parts darker, more
reddish and less grayish; sides of rump more reddish and less
grayish; underside of tail more tawny; skull distinctly longer
and broader across zygomata.

From _Eutamias minimus borealis_ (specimens from 1 mi. NW of
junction of Irons Creek and Laird River; N side Muskwa River, 4 mi.
W Ft. Nelson, 1200 ft.; E side Minaker River, 1 mi. W Trutch;
Beatton River, 115 mi. S Ft. Nelson; 5 mi. W and 3 mi. N Ft. St.
John; S side Toad River, 10 mi. S and 21 mi. E Muncho Lake; all in
British Columbia; and from Assineau River, 1920 ft., 10 mi. E and 1
mi. N Kinuso, Alberta), _E. m. silvaticus_ differs in: Under side
of tail more reddish; dorsal stripes less blackish; sides slightly
paler (less tawny); nasals distinctly shorter; skull distinctly
shorter.

_Measurements._--Average and extreme measurements of three adult
males and 11 adult females of _E. m. silvaticus_ from the type
locality are, respectively, as follows: Total length, 190
(189-190), 207 (202-220); length of tail, 85 (81-90), 97 (82-105);
length of hind foot, 31 (30-33), 32 (31-34); length of ear, 14
(13-16), 15 (14-17); weight, 45.7 (44.6-46.5), 55.7 (50.0-68.0);
greatest length of skull, 32.0 (31.5-32.6), 32.3 (31.5-33.1);
zygomatic breadth, 18.5 (18.5-18.5), 18.6 (18.2-19.0); least
interorbital constriction, 6.9 (6.8-7.1), 7.0 (6.4-8.1); length of
nasals, 9.4 (9.2-9.6), 9.6 (9.3-10.1).

_Measurements of the type._--Total length, 206; length of tail, 90;
length of hind foot, 32; length of ear, 15; weight, 59.3; greatest
length of skull, 32.6; zygomatic breadth, 18.6; least interorbital
constriction, 6.4; length of nasals, 9.3.

_Specimens examined._--Total number, 28. Specimens from South
Dakota are in the United States National Museum, and those from
Wyoming are in the Museum of Natural History of the University of
Kansas.

#South Dakota#: _Custer Co._: Custer, 3; _Lawrence Co._: Deadwood,
10.

#Wyoming#: _Crook County_: 3 mi. NW Sundance, 5900 ft., 14; 15 mi.
ENE Sundance, 3825 ft., 1.

Acknowledgment is made of assistance, with the field work, received
from the Kansas University Endowment Association.

_Museum of Natural History, University of Kansas, Transmitted
December 8, 1951._