PERODIPUS. 351 
interorbital constriction, 13; length of nasals, 13.5; mastoid width, 
23; length of upper molar series, 5; length of mandible, 18.3. 
357. obscurus (Perodipus), Allen, Bull. Am. Mus. Nat. Hist., ryo3, 
Pp: 603. 
Dusky KaNncGaAroo Rat. 
Type locality. Rio Sestin, State of Durango, Mexico. 
Genl. Char. Color very dark; size moderate. 
Color. Dorsal area gray brown suffused with fulvous; flanks 
more fulvous; lower half of cheeks, sides of neck, small spot above 
eye, postauricular patch, band on thighs, fore legs, inner side of 
hind legs and entire under parts white; tip of nose and bar at base 
of whiskers black; ear buffy white; tail with dorsal and ventral 
stripes blackish; sides and basal ring white. 
Measurements. Total length, 232; tail vertebrae, 130; hind foot, 
35; ear from notch, 12.7. Skull: total length, 36; greatest mastoid 
breadth, 23; length of nasals, 13. 
358. agilis (Dipodomys), Gambel, Proc. Acad. Nat. Scien. Phil., 
1848, p. 77. \ Elliot, Syn. N. Am. Mamm., 1901, p. 236. 
hermannt & wagnert Le Conte, Proc. Acad. Nat. Scien. Phil., 1848, 
Pp. 77- 
NIMBLE Kancaroo Rat. 
Type locality. Los Angeles, Los Angeles County, California. 
Geogr. Distr. Lower California, Mexico to southern and middle 
California. 
Genl. Char. Size small; color dark; body rather stout. 
Color. Above ashy brown, heavily lined with black, especially 
on top and sides of head and lower back; sides yellowish brown; 
spot over eye and behind ear, side of snout, stripe on thighs and 
under parts white; facial crescent black and broad, and meeting on 
bridge of nose; tail blackish and with a blackish tip, lateral white 
stripes terminating at base of pencil; under part of leg and base of 
foot dusky; rest white. 
Measurements. Total length, 280; tail vertebre, 170; hind leg, 
39.5; ear, 14.5. Skull: total length, 38; Hensel, 24; zygomatic 
width, 17.5; interorbital constriction, 12; mastoid breadth, 24; 
palatal length to incisive foramina, 7; median length of nasals, 7.5; 
length of upper molar series, 3.5; length of mandible, condyle to tips 
of incisors, 20. 
