DICE' — MAMMALS OF SOUTHEASTERN WASHINGTON 
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embryos, each about 3 mm, in length. As half-grown young were common at this 
time it is probable that more than one litter is produced a year. As shown by 
tracks in the dust the tail is sometimes held completely clear of the ground 
when traveling; it may touch the ground at each jump; or it may be allowed to 
drag constantly. 
A pocket mouse which was captured alive near Prescott August 3, 1910, was 
kept as a captive. He was fed on unthreshed heads of wheat, which he shelled 
out, placing the grains in his cheek pockets. The work of filling the pockets 
seemed to be mainly performed by the fore feet. When both pockets were full 
he would dig a hole in the ground on the floor of his cage and bury the wheat. 
He was offered bits of apple and potato, but did not eat them. After being kept 
for two weeks in a dry cage and fed only on wheat he was offered water, but 
refused it. Another pocket mouse captured in the same locality on August 25 
was placed in a jar without material for a nest. The next morning the tempera- 
ture had fallen to below 40® F. and the mouse was found cold and stiff. He was 
handled, but gave no signs of life. At 11 a.m. the temperature had risen and the 
mouse resumed activity. However, when the experiment was repeated the fol- 
lowing night the mouse did not recover. 
Perognathus lordi columbianus. Columbian Pocket Mouse. — Osgood (1900, 
p. 40) records specimens of this pocket mouse from Touchet. 
Perodipus ordii columbianus. Columbian Kangaroo Rat. — Found commonly 
during June, 1914, in the sagebrush east of Wallula. They seemed equally 
abundant on drifting sand and on packed sand areas. These animals are some- 
what active throughout the daytime as was shown by fresh tracks in sand where 
the wind was continually covering the old marks. In traveling the tail often 
touches the ground at each hop, but it may be carried entirely clear, or more 
rarely may be allowed to drag. 
Zapus princeps oregonus. Blue Mountain Jumping Mouse. — A number were 
trapped in early August, 1914, on top of the ridge near Twin Buttes Ranger Sta- 
tion. Nearly all were taken in thick brush, but one was taken in western larch 
forest not far from a patch of buckbrush where they were abundant. 
Erethizon epixanthtun epixanthum. Yellow-haired Porcupine. — A porcupine 
is reported to have been killed a few years ago along the Walla Walla River a 
short distance east of Wallula. A few have also been reported from the neigh- 
borhood of Prescott. Mr. Floyd Kendall reports that they occur in the Blue 
Mountains. 
Marmote, flaviventris avara. Pallid Yellow-bellied Marmot. — ^Common among 
the rocky cliffs on both sides of Snake River at Wawawai. 
Citellus columbianus columbianus. Columbian Ground Squirrel. — Common 
on the prairie and in the cultivated fields at Pullman. The large ground squirrels 
of the Touchet Valley and the Blue Mountains are also referred to this form, 
although they are larger in size and have a deeper red coloration on the flanks 
and tail than do specimens of the typical form from Pullman, Washington, and 
Moscow, Idaho. These squirrels are common along the Touchet Valley as far 
down as Lamar. At Prescott they occur in timber but are most abundant just 
at the edge of timber or brush. They occur along fences and sometimes climb the 
fence-posts. They are found in the open parts of the valleys and sometimes 
occur a half-mile or more out in the bunchgrass hills. In the Blue Mountains 
JOURNAL OF MAMMALOGY, VOL. I, NO. 1 
