228 SIGMODON. 
hispidus pallidus Mearns, Proc. U. S. Nat. Mus., 1898, p. 504. 
Elliot, Syn. N. Am. Mamm., 1901, p. 145. 
BERLANDIER’S Cotton Rat. 
Type locality. Rio Nazas, State of Coahuilla, Mexico. 
Geogr. Distr. Brownsville to El Paso, Texas, and Carlsbad, New 
Mexico; south to southern part of State of Jalisco, Mexico. 
Genl. Char. Smaller than S. lispidus texensis; ears larger, color 
paler. 
Color. Above buffy gray, mixed with black; under parts white; 
feet grayish white; tail dusky brownish above, grayish white beneath. 
Measurements. Total length, 242; tail vertebra, 103; hind foot, 
30; ear, 14. Skull: basal length, 30.5; zygomatic breadth, 19; mas- 
toid breadth, 13.4; length of nasals, 12.3; length of upper molar 
series, 6.5. 
hispidus arizone (Sigmodon), Mearns, Bull. Am. Mus. Nat. Hist., 
1890, p. 287. Elliot, Syn. N. Am. Mamm., rgor, p. 144. 
ARIZONA COTTON Rat. 
Type locality. Fort Verde, Yavapai County, Arizona. 
Geogr. Distr. Arizona into State of Sonora and Lower California, 
Mexico. 
Genl. Char. Larger than S. hispidus; ears larger; tail longer, 
colors paler. 
Color. Above light yellowish brown, mixed with ashy and lined 
with black; under parts white; tail dusky above, whitish below. 
Measurements. Average total length, 320; tail vertebrae, 121; 
hind foot, 35-36. Skull: total length, 40; zygomatic breadth, 23; 
length of nasals, 15.9; length of upper molar series, 7.1. 
hispidws major (Sigmodon), Bailey, Proc. Biol. Soc. Wash., xv, 
[902, P- 109. 
LARGE CoTTon Rat. 
Type locality. Sierra de Choix, 50 miles northeast of Choix, State 
of Sinaloa, Mexico. 
Geogr. Distr. Province of Tepic to southern part of State of 
Sonora, Mexico. 
Genl. Char. Very large; feet stout. Skull heavily ridged in adults; 
interparietal strap-shaped, ends rounded; nasals notched posteriorly; 
audital bull large, elongated. 
Color. Above light brownish gray; nose yellowish; beneath 
white; hands and feet light gray; tail above blackish, beneath dark 
gray. 
Measurements. Total length, 365; tail, 156; hind foot, 40.5. 
Skull: basal length, 36; nasals, 16; zygomatic breadth, 23.5; mastoid 
