68 



NORTH AMEEICAN FAUNA. 



[NO. 39. 



Distribution. — San Pedro Martir Mount ains, Lower California (fig. 7) . 



Characters. — Size considerably larger than nigricans; skull longer; 

 colors grayer in both winter and summer pelage. 



Color. — Winter pelage: Very long and dark gray, not so black as in 

 nigricans; underparts buffy gray; tail and feet grayish; lining of 

 cheek pouches white; no white on chin and throat. Summer pelage: 

 DuU fulvous, not so intense as in nigricans or fulvus. 



Slcull. — Adult males: Very long and narrow, with especially nar- 

 row zygomatic arches and long, narrow braincase, in these characters 

 apparently exceeding neglectus and jacinteus; dorsal outline arched, 

 and rostrum depressed about as in nigricans. 



Measurements. — Type ( ad.): Total length, 248; tail vertebrae, 

 67; hind foot (measured dry), 31. The tail measurement of type is 

 short; other specimens have longer tails, 8 females averaging 70. 

 Slcull: Basal length, 41.6; nasals, 15; zygomatic breadth, 25; mas- 

 toid breadth, 21; interorbital breadth, 6.5; alveolar length of upper 

 molar series, 8. 



Remarks. — This is evidently a very local form occupying some high 

 valley or the crest of the range, since other series from not far distant 

 in the same range and only a little lower down, as at Vallecitos at 

 8,000 feet altitude. La Grulla at 7,000 feet, and Santo Tomas at 6,000 

 feet, are typical of nigricans. In December, 1914, A. W. Anthony 

 wrote me that the type series of specimens was collected at La Grulla 

 Meadows at 8,200 feet altitude in the San Pedro Martir Mountains, but 

 the series of specimens collected by Nelson and Goldman at La 

 GruUa (7,000 feet) are nigricans. 



As the mountains rise to 10,200 feet, this may be a mountain-top 

 form of considerable range. The true relationship of these high- 

 mountain forms from alpinus to martirensis is not very clear and will 

 not be until definite field study shows whether they merge into lower 

 forms or are distinct and isolated. 



Specimens examined. — Fourteen, from type locality. 



Thomomys perpallidus Group. 

 THOMOMYS PERPALLIDUS PERPALLIDUS Merriam. 

 Palm Springs Pocket Gopher. 



(PL V, fig. 2.) 



Thomomys talpoides perpallidus Merriam, Science, VIII, 588, Dec. 24, 1886. 



Type. — Collected at Palm Springs (Agua Caliente) Riverside County, 

 Cahfornia (at sea level on the edge of the Colorado Desert, 6 miles 

 south of Palm Springs Station), by F. Stephens, March or April, 

 1886.^ Type specimens in U. S. Nat. Mus., Merriam collection. 



1 In the original description no type was designated by number, but Dr. Men-iam refers to several skins 

 collected by F. Stephens in March and April on the Colorado Desert. In the Merriam collection are 4 

 skins and skulls labeled in accord with this statement, Nos. |f Mcf , f f H(f , f?-ftcf , and fff^ $ . Of these 

 No. f in is the only fully adult male and should have been made the type. 



