304 Field Columbian Museum — Zoology, -Vol. TTL 



checks its vertical range at about 4,000 feet, the lower limit of 

 the rive-toed species. South of the range of Perodipus pana- 

 mi 11 tin its the allied D. m. simiolus ranges up to 6,000 feet, where 

 it enters the lower edge of the Pirion Zone." 



Dipodomys deserti. 



Dipodomys deserti Steph.. Amer. Nat., xxi, 1881. p. 42. Elliot, 

 Syn. X. Am. Mamm., 1901, p. 235. 



40 Examples: 4 Palm Springs, 27 Daggett, 2 Ballarat, 7 Fur- 

 nace Creek, Death Valley. 



At Daggett, where most of the specimens were taken, this 

 species was ''abundant in the white sand area of the river bed 

 to which it is confined. In Death Valley it was abundant 

 everywhere about sandy soil and mesquite vegetation. Known 

 locally as the mesquite-rat on account of the large quantity of 

 mesquite-pods they store away in underground cavities. The 

 Indians often dig open the burrows and gather their supply of 

 pods from the rats, from which, after being ground into a flour, 

 a vellowish bread is made." 



Dipodomys deserti helleri. 



Dipodomys d. helleri Elliot, Pub. Field Columb. Mus.. in. 1903, 

 p. 249. 



6 Specimens from Keeler. 



A richly colored race, similar in hue to D. m. nitraius, which 

 was "common in the sand dunes a little beyond the margin of 

 the grass, and evidently confined to a zone about the lake." 



PERODIPUS. 

 Perodipus agilis. 



Perodipus agilis Gambel, Proc. Acad. Nat. Scien. Phil., 1848, 

 p. 77. Elliot, Syn. N. Am. Mamm.. 1901, p. 236. 



15 Specimens: 1 Banning, 1 Fort Tejon, 2 Bailey's Ranch, 

 8 Castac Lake, 3 Lockwood Valley, Mount Pinos. 



"This species extends as far east as the summit of San Gorgonio 

 Pass, where it was found near Banning, and the burrows were 

 seen near Beaumont at the summit. In the Mount Pinos region 

 it was common in the valleys and ravines, as high as the lower 

 limit of the black pines or up to 6.000 feet altitude. They cross 

 the Tehachapi Mountains in the vicinity of Fort Tejon, where 

 thev were found from the edge of the San Joaquin Valley east- 

 ward through the pass to Antelope Valley." 



