434 



BULLETIN 



UNITED STATES NATIONAL MUSEUM. 



mens of this species from east of Sonoyta are referred to the subspecies 

 anihonyi. It prefers rocky places and requires less moisture than 

 the members of the plains-mice group. At Sonoyta and Quitobaquita 

 it abounded in the huts and brush fences of the Papago and Mexi- 

 cans. Some nests of grass, feathers, and stems and leaves of plants 

 were found in the fences. A nest containing four yomig was placed 

 in a box. The mother followed and entered the box. In my tent she 

 was again liberated, but returned to her progeny in the box. This 

 mouse appeared very slender and light when compared in the flesh, 

 with Peromyscus merriami and the latter was always found in 

 fields and never in houses. 



The western desert mouse was quite common on the lower Gila 

 and Colorado rivers, though much less numerous than the plains 

 mouse. Its range did not extend to the low savannas about the 

 mouth of the Colorado River, where Peromyscus sonoriensis deserticola 

 is most abundant. Seven pregnant females were examined January 9 

 to April 15, the young numbering 4, 4, 3, 1, 4, 2, and 3. 



Record and measurements of 6S specimens of typical Peromyscus eremicus. 



Four young ol No. 2779. 



!i Alcoliolio. 



