306 Field Columbian Museum — Zoology, Vol. III. 



10 Specimens from Wild Rose Spring, Panamint Valley. 



"The gravelly mesas near Wild Rose Spring, at the north 

 end of the Panamint Range, supported large numbers of this 

 pocket-mouse, which here outnumbered all other mammals in 

 abundance. The range extended to the lower edge of the 

 Juniper Belt, 6,500 feet, and down the eastern slope to about 

 4,000 feet, the species not occurring apparently in Death Valley. 

 On the western slope of the range it descends to Panamint Valley, 

 where it is fairly common." 



Perognathus panamintinus bangsi. 



Perognathus p. bangsi Mearns, Bull. Am. Mus. Nat. Hist . 

 1898, p. 300. 



43 Specimens: 1 Castac Lake, 1 Bailey's Ranch, 9 Oro 

 Grande, 5 Daggett, 3 Calico Mountains, 12 Copper City, 9 Lane's 

 Mill, 3 Ballarat. 



This race so closely resembles the preceding species that it is 

 almost impossible to distinguish one from the other. Mr. 

 Osgood (N. Am. Faun., No. 18, p. 2q) says, "a convenient 

 character to distinguish them is the color of the upper side of 

 the tail, which is normally dusky in panamintinus and buffy in 

 bangsi." Perhaps for many examples this rule will answer as 

 well as any other, but there are a number of specimens which 

 have dark tails from the same locality as those having buff tails, 

 and then it becomes a good deal a matter of guesswork, unless 

 one is willing to rely entirely upon the locality itself to determine 

 the name of the specimen. Mr. Heller says of this race that 

 "on the higher part of the Mohave desert on gravelly mesas 

 supporting creosote bushes, this race is usually common. About 

 Oro Grande and Daggett it was rare, but farther north in the 

 vicinity of Pilot Knob it occurred so numerously that seventy- 

 five per cent of the traps set contained this form. The burrows 

 were invariably placed beneath the roots of creosote bushes in 

 this locality. A single specimen was secured as far north as 

 • Coso Valley. At Antelope Valley the race ranges westward 

 from the Mohave, and crosses the divide, occurring as low down 

 as Fort Tejon, where, however, it is rather uncommon. It also 

 occurs on the west slope of the mountains at Bailey's Ranch 

 on Piru Creek." 



Perognathus longimembris. 



Perognathus longimembris Coues, Proc. Acad. Nat. Scien. Phil., 

 1875, p. 305. Elliot, Syn. N. Am. Mamm., 1901, p. 247. 



