110 CALIFORNIA MAMMALS. 



Rather common in the foothills along the western border of 

 the Colorado Desert. 



Peromyscus eremicus herroni Rhoads. (For R. B. 

 Herron. ) 



HERRON MOUSE. 



Similar to eremicus; darker ; sides less buffy, the color of 

 the back shading' further down the sides ; belly grayish white. 



Type locality, south side of San Bernardino Valley, Califor- 

 nia. 



Herron Mice are intermediate between the Hermit Mice and 

 Dulzura Mice in color and in habitat. They live in the drier 

 warm interior valleys, and their borders in the southern part of 

 California, from northern San Diego County northward. They 

 are common in few places. 



Peromyscus eremicus fraterculus Miller. (Little 

 brother.) 



DULZURA MOUSE, 



Darker than eremicus or lierroni; above dark grayish wood 

 brown or yellowish bistre rather thickly intermixed with black, 

 shading on the sides to brownish ochraceous buff; belly cream 

 buff in typical specimens but often pale grayish buff or grayish 

 white; a buff pectoral spot is frequently present. 



Type locality, Dulzura, San Diego County, California. 



Rather common in brush along the coast and mesas and 

 western slopes of the coast mountains from northwestern Lower 

 California northwest to Ventura County, California. The north- 

 ernmost specimens intergrade with Herron Mice and the eastern 

 ones with Palm Desert Mice. 



Genus Sigmodon Say and Ord. (Sigma — tooth.) 

 Upper incisors broad; rostrum broad and short ; zygomatic 

 arches very wide posteriorly ; border of orbits beaded ; coronoid 

 process of lower jaw of moderate size; a process of the maxillary 



