PEROMYSCUS, 201 
WHITE-TAILED MOUSE. 
Type locality. Tehuantepec, Mexico. 
Geogr. Distr. Southern Mexico. 
Genl. Char. Size about that of P. calsfornicus; ears large; tail 
long, distal half white. 
Color. Above cinereous gray lined with black; under parts white; 
hands and feet white; tail, proximal half brown, distal half white; 
ears blackish brown. 
Measurements. Total length, 260; tail, 142; hind foot, 25.5; ear 
from notch, 17.5. Skull: greatest length, 30.3; greatest breadth, 15; 
length of nasals, 11.2; breadth of nasals, 3.4; interorbital constriction, 
5.1; interparietal breadth, 10; interparietal length, 3.9; palatal length, 
11.9; length of upper molar series, 4.5; length of mandible, condyle 
to tip of incisor, 18.2; height of coronoid process, 7.4. 
a.—sadovi (Peromyscus), Thomas, Ann. Mag. Nat. Hist., 7th Ser., 
Ml 1009, p: 4164. 
Gapow’s Mouse. 
Type locality. San Carlos, Yautepec, State of Oaxaca, Mexico. 
Altitude, 2,250 feet. 
Genl. Char. Similar to P. leucurus, color darker, ears larger. 
Color. Upper parts pale brown tinged with buff; sides like back; 
under parts soiled grayish; chin white; hands and feet white; tail 
black above and at tip, beneath white. 
Measurements. Total length, 265; tail, 150; hind foot, 27.6; ear, 
25. Skull: greatest length, 31.5; basilar length, 24; zygomatic 
breadth, 4.2; breadth of braincase, 14; interparietal, 4.211.5; 
palatal length, 12.5; palatal foramina, 6.62.6; length of upper 
molar series, 4.7. 
172. melanophrys (Hesperomys), Coues, Proc. Acad. Nat. Scien. 
ri £574, 0. Ler. 
BLACK-BROWED Mouse. 
Type locality. Santa Efigenia, Tehuantepec, State of Oaxaca, 
Mexico. 
Geogr. Distr. Southern Mexico, Tehuacan and Tehuantepec, 
States of Puebla and Oaxaca. 
Genl. Char. Size large; tail longer than head and body; ears 
large. Skull: palate ending opposite last molars. 
Color. Above gray, tinged with fulvous, darker on dorsal line; 
sides fulvous; head gray; orbital ring black; under parts pure white; 
hairs at base plumbeous; hands and feet white; tail above like the 
back, beneath gray. 
Measurements. Total length, 245; tail vertebrae, 135; hind foot, 
