FIELD BOOK OF MAMMALS 



Gila Cotton Rat. — Sigmodon hispidus confinis Goldman. 

 A rather small, dark subspecies. Upperparts mixed buff 

 and blackish; ears grayish; tail above, brownish, below, 

 grayish; underparts whitish to grayish. Total length, ii 

 inches; tail vertebrae, 4.5 inches; hind foot, 1.24 inches. 

 Found in "Upper part of Gila River Valley in southeastern 

 Arizona." (Goldman) 



Cienega Cotton Rat. — Sigmodon hispidus cienegcs A. B. Howell. 

 Resembling confinis but slightly larger; darker and slightly 

 browner than eremicus. Total length, 12.3 inches; tail 

 vertebras, 5.2 inches; hind foot, 1.4 inches. Found on the 

 upper Santa Cruz River system, Pima County, Arizona. 



Western Cotton Rat.^ — Sigmodon hispidus eremicus Meams. 

 Slightly larger than typical hispidus; paler; pelage softer, 

 Upperparts pale yellowish gray; feet light gray; tail brown 

 above, gray below; underparts whitish. Total length, 11 

 inches; tail vertebrae, 5 inches; hind foot, 1.36 inches. 

 Found "Along both sides of the lower Colorado River." 

 (Bailey) 



Arizona Cotton Rat. — Sigmodon hispidus arizoncB Meams. 

 Larger and paler than typical hispidus. Upperparts light 

 buffy gray; light yellowish touch on nose; underparts white. 

 Total length, 12.8 inches; tail vertebrae, 5 inches; hind foot, 

 i.o inch. Found in Yavapai County, Arizona. 



Jackson Cotton Rat. — Sigmodon hispidus jacksoni Goldman. 

 Pale and resembling eremicus, Upperparts light ochraceous 

 buff mixed with dusky; sides only slightly paler; tail brown- 

 ish above, grayish below; underparts whitish to grayish. 

 Total length, 10 inches; tail vertebrae, 4.3 inches; hind foot, 

 1.3 inches. Found in the plateau region near Prescott, 

 Arizona. 



Fulviventer Group 



Least Cotton Rat. — Sigmodon minimus minimus Meams. 

 Size small; tail hairy; pelage not hispid. Upperparts clear 

 grizzled gray; feet gray; tail above and below brownish 

 black; underparts buffy. Total length, 9 inches; tail verte- 

 brae, 3.8 inches; hind foot, i.i inches. Found in "Mountains 

 of southern New Mexico, Arizona, and northern Mexico." 

 (Bailey) 



Goldman Cotton Rat. — Sigmodon minimus goldmani Bailey. 

 Resembling typical minimus but darker in color. Upper- 

 parts grizzled white, buff and black; ears and tail blackish; 

 feet dark; underparts dark, rich fulvous. Total length, 

 10.2 inches; tail vertebras, 4.3 inches; hind foot, 1.24 inches. 

 Found in Quay County, New Mexico. 



Yellow- jawed Cotton Rat. — Sigmodon ochrognathus Bailey. 

 Slightly larger than typical minimus and with strong orange 

 yellowish tinge about ears, face, and rump. Upperparts 

 yellowish gray; bright ochraceous on nose, about eye, and 



378 



