PEROMYSCUS. 183 
9.8X2.5; palatal length, 3.5; palatine foramina, 5.72; postpalatal 
length, 9.1; length of upper molar series, 3.8. 
leucopus fulvus. 
sonoriensts fulvus (Peromyscus), Osgood, Proc. Biol. Soc. Wash., 
RVI, IQA, p. 57. 
Futvous Mouse. 
Type locality. Oaxaca City, State of Oaxaca, Mexico. 
Genl. Char. Similar to P. 1. sonoriensis, but darker. ‘‘ Skull with 
anterior part of zygoma heavier, more deeply notched by infraorbital 
foramen.”’ 
Color. Upper parts russet; middle of back mars and Prout’s 
brown; under parts creamy white; ear tufts buffy or pale cream 
color; hands, arms, and feet white; outer side of ankles brownish; 
tail above brown, beneath white. 
Measurements. Total length, 167; tail vertebrae, 68; hind foot, 
22. Skull: greatest length, 25; Hensel, 19.5; zygomatic width, 12.8; 
interorbital constriction, 4; interparietal, 82.1; length of nasals, 10; 
length of palate, 3.7; palatal foramina, 5.62; postpalatal length, 8.7; 
length of upper molar series, 3.8. 
139. exiguus (Peromyscus), Allen, Bull. Amer. Mus. Nat. Hist., 1898, 
Pp. 157. 
SAN Martin Istanp Mouse. 
Type locality. San Martin Island, Lower California, Mexico. 
Geogr. Distr. Lower California, Mexico. 
Genl. Char. Similar to P. t. clementts, smaller, tail shorter. 
Color. Head and back dark rufous brown, darkest on upper 
back, but no dorsal stripe; flanks pale rufous; upper lip, chin, and 
under parts pure white; orbital ring black; ears like back; tail above 
dark brown, beneath white; feet white. 
Measurements. Total length, 158; tail vertebre, 69; hind foot, 
20. Skull: total length, 26.5; basal length, 22; mastoid breadth, 
I1.5; interorbital constriction, 3.5; length of nasals,10. (ex Type.) 
140. cherrii (Hesperomys), Allen, Bull. Amer. Mus. Nat. Hist., 1891, 
Dp. 202. 
CHERRIE’s Costa Rican Mouse. 
Type locality. La Carpintera, Costa Rica. 
Geogr. Distr. Costa Rica. 
Genl. Char. Similar to P. nuttalli, but whiter beneath; ears 
larger, tail much longer. 
Color. Above @ark cinnamon rufous, lined with black on the 
head and dorsal region; flanks rusty cinnamon; upper lip on a line 
