122 CALIFORNIA MAMMALS. 



■erature, are then less lively and the hair is slightly raised, espec- 

 ially on the head." 



Neotoma abigula venusta True;. (White — throat; 



beautiful.) 



MESQUIT BRUSH RAT. 



Above mixed dusky and ochraceous buff; darkest on the 

 crown and back, lighter and more buffy on the sides; below 

 white; feet white; tail bicolor, blackish above, dull white below; 

 skull strong and angular; rostrum short, wide and deep, depress- 

 ed; nasals wide and broadened anteriorly, narrowed to a wedge 

 shape posteriorly ; frontal shortened posteriorly and parietals cor- 

 respondingly lengthened; incisive foramina short. Young; paler 

 gray than usual in this genus. 



Length about 370 mm. (14.50 inches) ; tail vertebrae 175 

 (6.90); hind foot 35 (1.40); ear from crown 30 (1.18). 



Type locality, Carrizo Creek, California. (In foothills bor- 

 dering the Colorado Desert.) 



The Mesquit Brush-Rats are most common in shrubby 

 imasses of mesquit scattered through the Colorado' Desert and in 

 .the Colorado Valley. They also occur some distance up the 

 gulches and canyons of the adjoining foothills. Their principal 

 food is the mesquit "beans" and twigs. They are less given to 

 nest bulding than most Brush-Rats, living more in burrows under 

 mesquit trees. The breeding season is similar to that of the 

 genus in general. 



Subfamily Microtinae. 



Skull short and broad ; rostrum; short ; nasals short, not pro- 

 jecting beyond premaxillaries ; enlargement at root of lower in- 

 cisor near base of condylar process of jaw greatest on inner sur- 

 face; angular process bent back and up until its tip reaches above 

 the plane of the summits of lower molars ; notch between tip of 



