156 CALIFORNIA MAMMALS. 



Dipodomys californicus pallidulus Bangs. 



COLUSA POCKET-RAT. 



Similar to californicus but paler: above wood brown, shad- 

 ing to cinnamon on the sides ; tail aboA'e sepia, beneath white. 



Length 290 mm. ( 1 1.40 inches) ; tail vertebrae 181 (7.15) ; 

 hind foot 42 (1.65). 



Type locality, Sites, Colusa County. California. 



Dipodomys deserti Stephens. (Of the desert.) 



DESERT POCKET-RAT. 



Large and pale; above grayish buff, the hairs ashy gray 

 at base; shoulders and upper part of sides lighter, the .hairs white 

 at base; white spot behind the ear large, sometimes reaching the 

 shoulder; soles of hind feet dirty white; upper side of tail white 

 at base, then buffy or brownish to past the middle, then drab 

 gray to the white tip, under side white; other marking as usual; 

 skull large; inflation of mastoids extreme; supraoccipetal nar- 

 rowed almost to a line on the upper surface ; interparietal usually 

 obliterated in adults. 



Length about 340 mm. (13.40 inches) ; tail vertebrae 205 

 (6.10) ; hind foot 53 (2.10) ; ear from crown 15 (.60). 



Type locality, Mojave River, near Hesperia. California. 



Desert Pocket-Rats occur in southern California, southern 

 Nevada, western Arizona, northwestern Sonora and northeastern 

 Lower California. The northwestern extreme of their range is 

 Owen Valley, Inyo County, where I have trapped thein near 

 Alvord. None have been taken on the coast side of the moun- 

 tains. 



This species occurs in small colonies, less commonly in pairs, 

 rarely singly. The habitation is often a labyrinth of intercom- 

 municating burrows from a few inches to two feet beneath the 

 surface, commonly under a low mound formed of sand and dust 

 drifted about a shrub, but sometimes in a level space. Frequent- 

 ly the interior is honeycombed with burrows until little more than 



