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 (Pcrodipus), Allen, Bull. Am. Mus. Nat. Hist., 1903, 



p. 603. 

 DUSKY KANGAROO 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. 

 hermanni & wagncri Le Conte, Proc. Acad. Nat. Scien. Phil., 1848, 



P- 77- 

 NIMBLE KANGAROO 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 vertebras, 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. 



