lege, and Mr.
James S. Findley, generously loaned specimens for my use.
Doctors E. Raymond Hall, Rollin H. Baker, Robert W. Wilson,
Keith R. Kelson, E. Lendell Cockrum, and other friends and
associates have given valued suggestions and assistance. My
wife, Alice M. White, made the illustrations and helped me
record and analyze the data.

Assistance with field work is acknowledged from the Kansas
University Endowment Association, the National Science
Foundation, and the United States Navy, Office of Naval
Research, through contract No. NR161 791.

ACCOUNTS OF SPECIES AND SUBSPECIES

=Eutamias quadrivittatus= (Say)

_Diagnosis._--Size medium; general tone of upper parts tawny; cranial
breadth averaging between 16.0 and 16.8 mm.; baculum distinguishable
from that of any other species by the combination of width of base
less than 1/4 of length of shaft, shaft having a maximum diameter of
more than 1/4 mm., and height of keel 1/4 of length of tip.

=Eutamias quadrivittatus quadrivittatus= (Say)

_Sciurus quadrivittatus_ Say, in Jones, Long's
Expedition to Rocky Mountains, 2:45, 1823.

_Eutamias quadrivittatus_, Miller and Rehn, Proc.
Boston Soc. Nat. Hist., 30:43, December 27, 1901.

_Tamias quadrivittatus gracilis_ J. A. Allen, Bull.
Amer. Mus. Nat. Hist., 3:99, June 1890, Type from
San Pedro, Santa Fe Co., New Mexico.

_Eutamias quadrivittatus animosus_ Warren, Proc.
Biol. Soc. Washington, 22:105, June 25, 1909. Type
from Irwin Ranch, Las Animas County, Colorado.

_Type._--None designated; from along Arkansas River, about 26
mi. below Canon City, Fremont County, Colorado; obtained on
July 18, 1820.

_Diagnosis._--Size medium; dorsal dark stripes blackish;
sides Cinnamon to Clay Color; crown Light Drab; baculum
large.

_Description._--_Color pattern_: Head Cinnamon, shaded on
crown to Light Drab; ocular stripe Fuscous Black, with
Cinnamon along margins; other facial stripes Fuscous mixed
with Cinnamon; ears Fuscous Black, Ochraceous-Tawny on
anterior margin, grayish white on posterior margin and on
postauricular patch; dark dorsal stripes black with
Ochraceous-Tawny along margins; outer pair of dark stripes
often mainly Tawny; light dorsal stripes grayish white, outer
pair usually