salis_, and _E. merriami_, see the
accounts of those species.

Baculum of _E. q. hopiensis_: Shaft thick; keel proportionally low, 1/3
of length of tip; tip 34 per cent of length of shaft; angle formed by
tip and shaft 130 deg.; distal 1/3 of shaft slightly compressed laterally;
shaft short, 2.64 mm. in length.

Differs from _E. ruficaudus ruficaudus_, _E. r. simulans_, _E.
cinereicollis_, and _E. quadrimaculatus_, in being shorter, proportions
as in _E. q. quadrivittatus_; from _E. speciosus_, _E. panamintinus_,
_E. umbrinus_, _E. palmeri_, and _E. bulleri_, in base not markedly
widened, angle formed by tip and shaft larger; from _E. alpinus_, _E.
minimus_, _E. townsendii_, _E. sonomae_, _E. amoenus_, _E. dorsalis_,
and _E. merriami_, except for smaller size, as in _E. q.
quadrivittatus_.

Bacula of _E. q. hopiensis_ from northeastern Arizona are like those in
typical _E. q. quadrivittatus_. The specimens from this region, to judge
from parts of the animal other than the baculum, are intergrades between
_E. q. hopiensis_ and _E. q. quadrivittatus_. Specimens from near Moab,
Grand Co., Utah, are typical _E. q. hopiensis_ and the bacula of these
specimens are considerably smaller than those of specimens of typical
_E. q. quadrivittatus_. No bacula are known to me that are structurally
intermediate between those of _E. q. quadrivittatus_ and _E. q.
hopiensis_.

_Specimens examined_: 21.

_E. quadrivittatus quadrivittatus_: Colorado: _Gunnison Co._:
Sapinero, 1 (BS). _Chaffee Co._: Unspecified, 1 (MM). _Saguache
Co._: 5 mi. N and 22 mi. W Saguache, 10,000 ft., 1. _Fremont
Co._: Canon City, 3 (BS). New Mexico: _Rio Arriba Co._: Dulce, 1
(BS). _Taos Co._: 23 mi. S and 6 mi. E Taos, 8,750 ft., 4.
_Union Co._: Sierra Grande, 1 (BS). _Valencia Co._: Mirror
Spring, Mt. Taylor, 3 (MM). _Torrance Co._: S end, E slope,
Manzano Mountains, 2 (BS).

_E. quadrivittatus hopiensis_: Utah: _Grand Co._: Mouth of
Nigger Bill Canyon, E side Colorado River, 4 mi. N Moab Bridge,
4,500 ft., 1 (UU); Moab, 4,500 ft., 1 (UU). Arizona: _Apache
Co._: Tunicha Mountains, 1 (BS).

#Eutamias ruficaudus# Howell

Figures 11-12

General tone of upper parts dark tawny; size medium; braincase
narrowed.

Baculum of _E. r. ruficaudus_: Shaft thick; keel proportionally low, 1/4
of length of tip; tip 31 to 33 per cent of length of shaft; angle
formed by tip and shaft 120 deg.; distal 2/