228 THOMOMYS. 



Genl. Char. Size medium; tail half as long as body and head; 

 claws large, long. 



Color. Above reddish brown, darkest on dorsal region; sides 

 and under parts yellowish white, tinged with rufous on abdomen; lips 

 and ears dusky; inside of pouches whitish; tail with basal part like 

 back. 



Measurements. Total length, 239; tail vertebrae, 79; hind foot, 

 29; ear, 8. 



a.— nigricans. {Thomomys), Rhoads, Proc. Acad. Nat. Scien. Phil., 

 1895, p. 36. 



Type locality. Grapelands, San Bernardino Valley, California. 



Geogr. Distr. Southern California. 



Genl. Char. Size large; claws short, thick; skull massive, angu- 

 lar; dentition weak; interparietal longer than wide. 



Color. Above tawny brown, rump lighter; head blackish; ears 

 and aural patch sooty; beneath tawny ash; feet and lower surface of 

 limbs ash. 



Measttrements. Total length, 260; tail vertebrae, 89; hind foot, 

 33.5. Skull: total length, 39; zygomatic breadth, 24.4; basilar 

 length, 35.5; nasals, 11.9; interorbital constriction, 6.9; length of 

 mandible, 25. 



h. — intermedius. (TAomomys), Mearns, Proc. U. S. Nat. Mus. Wash., 

 1897, xix, p. 719. 



Ty/e locality. Huachuca Mountains, Arizona. 



Geogr. Distr. Mountains connecting Colorado Plateau with that 

 of Mexico. 



Genl. Char. Smaller than T. ftilvus. 



Color. General hue Mars brown, dorsal area plumbeous black; 

 feet and tail soiled white. Base of under fur plumbeous. 



Measurements. Total length, 220; tail vertebrae, 66; hind foot, 24. 



344. annularis. {Thomomys), Merr. , Proc. Biol. Soc. Wash., 1897, 

 p. 214. 



Type locality. Los Banos, Merced County, California. 



Geogr. Distr. Western California. 



Genl. Char. Size medium; skull similar to that of T. fulvus, but 

 more massive; zygomata larger and more spreading; pterygoids 

 larger; larger angular processes of mandible; incisors more promi- 

 aent. 



Color. Above fulvous mixed with black, most numerous on 

 median line; nose and ears blackish; beneath plumbeous washed with 

 buffy ochraceous; feet and tail whitish. 



Measurements. Total length, 257; tail vertebrae, 75; hind foot, 32. 



