SIGMODON. 231 
Color. Above yellowish gray, tinged about ears, face, and rump 
with ochraceous; nose, orbital ring, and base of tail bright ochraceous; 
beneath white; hands and feet buffy gray; tail above blackish, 
beneath buffy gray. 
Measurements. Total length, 260; tail, 117; hind foot, 29. 
Skull of type: basal length, 28; nasals, 11.6; zygomatic breadth, 19; 
mastoid breadth, 13; alveolar length of upper molar series, 5.5. 
(Bailey, 1. c.) 
205. alticola (Sigmodon), Bailey, Proc. Biol. Soc. Wash., xv, 1902, 
Dp. 216. 
ALPINE Cotton Rat. 
Type locality. Cerro San Felipe, State of Oaxaca, Mexico. 
Altitude, 10,000 feet. 
Geogr. Distr. Mountains of State of Oaxaca, Mexico. 
Genl. Char. Size medium; tail hairy; pelage long and soft. 
Skull: similar to that of S. leucotis; lateral pits of palate very shallow. 
Color. Above dark ochraceous or light umber brown; beneath 
pale cinnamon brown; hands and feet yellowish gray; tail black, 
vellowish brown at base beneath; ears gray. 
Measurements. Total length, 230; tail, ror; hind foot, 28.5. 
Skull of type: basal length, 28.5; nasals, 11; zygomatic breadth, 17.8; 
mastoid breadth, 13.5; alveolar length of upper molar series, 6.3. 
(Bailey, 1. c.) 
a.—amoles (Sigmodon), Bailey, Proc. Biol. Soc. Wash., xv, 1902, 
Dp. 116. 
AMOLES CoTTON Rat. 
Type locality. Pinal de Amoles, State of Queretaro, Mexico. 
Geogr. Distr. Known only from type locality. 
Genl. Char. Similar to S. alticola. Skull wider, smaller bulle, 
and lateral pits of palate deeper, and interparietal without median 
division. 
Color. Like S. alticola, but upper parts duller and less tawny. 
Measurements. Total length, 252; tail vertebre, 105; hind foot, 
29.5. Skull of type: basal length, 29.5; nasals, 5.7; zygomatic 
breadth, 19.6; mastoid breadth, 14; alveolar length of upper molar 
Series, 6.3. (Bailey, 1. c.) 
206. austerulus (Sigmodon), Bangs, Bull. Mus. Comp. Zodl., xxx1x, 
1902, p. 32. 
VOLCAN DE CHIRIQUI CoTTON Rat. 
Type locality. Volcan de Chiriqui, Chiriqui, Panama. Altitude, 
10,000 feet. 
