86 



txo. 39. 



THOMOMYS FULVUS TOLTECUS Allen. 

 ToLTEc Pocket Gopher. 



(PI. VI, fig. 3.) 



Thomomys toltecus Allen, Bui. Am. Miis. Nat. Hist., V, 52, Apr. 28, 1893. 



Type. — Collected at Colonia Juarez, Mexico (on the Casas Grandes 

 River at about 4,500 feet altitude in northwestern Chihuahua), by 

 F. Robinette,^ 1890. Labeled Juarez, N. Sonora." Type specimen 

 in Am. Mus. Nat. Hist. 



Distribution. — Lower Sonoran valleys and deserts of southeastern 

 Arizona, southwestern New Mexico, and adjacent parts of Chihuahua 

 and Sonora, south to Colonia Juarez, Chihuahua (fig. 7). 



Characters. — Size about as in fulvus or slightly larger; colors 

 paler and grayer; ears and claws medium; mammae in 4 pairs. 



Color. — Summer pelage (June specimens from Casas Grandes): 

 Upperparts dull ochraceous-tawny; nose brownish; ear patch black; 

 underparts hghter ochraceous-tawny; tail buffy gray; feet whitish. 

 Winter pelage: Upperparts dark gray with a tawny suffusion over 

 sides, and usually an indistinct dusky median line along back; nose 

 and ear patch dusky; underparts light fawn or pinkish buff. 



S~kuU. — Very like that of fulvus but more angular, less arched, 

 with wider nasals, larger bullae, and about the same dentition. 



Measurements. — ^Adult male from Casas Grandes: Total length, 

 221; tail vertebrae, 72; hind foot, 31.5. Adult female from same 

 locality: 205, 66, 29. Slcull (of male): Basal length, 37; nasals, 13; 

 zygomatic breadth, 25; mastoid breadth, 20.5; interorbital breadth, 

 7; alveolar length of upper molar series, 7.8. Skull (of type): 41, 14, 

 26, 21, 7, 8. 



Remarlcs. — This is a light-colored valley form of the fulvus group 

 occupying the upper edge of Lower Sonoran deserts of southern 

 New Mexico and Arizona and northern Chihuahua. It is readily 

 distinguishable from the smaller and grayer lacJiuguilla of the Eio 

 Grande Valley, which occurs also at Casas Grandes and seems to 

 be distinct. In Arizona it may grade into cervinus of the Gila VaUey 

 and in Sonora possibly into sinalose. 



Specimens examined. — Total number, 175, as follows: 

 Arizona: Calabasas, 5; Chiricahua Mountains, 4; Dos Cabesas, 1; Fairbank, 

 24; Fort Bowie, 6; Fort Grant, 4; Fort Huachuca, 5; Fort Lowell, 12; Graham 

 Mountains (Ash Creek, at 6,100 feet altitude), 3; Huachuca Mountains, 

 9; La Osa, 11; Mammoth, 1; Oracle, 2; Safford, 9; San Bernardino Ranch 

 (Mexican boundary), 33; San Xavier, 1; Tucson, 2; Wilcox, 2. 

 Chihuahua: Casas Grandes, 2; Colonia Diaz, 3; Colonia Juarez, 6; Espia, 1. 

 New Mexico: Adobe Ranch (north base Animas Mountains), 1; Cuchillo, 1; 

 Deming, 3; Garfield, 2; Hachita, 3; Lake Valley, 2; Las Palomas, 2; Mimbres 

 River, 1; Monument No. 40, Mexican boundary, (upper corner, 100 miles 

 west of El Paso), 3; Red Rock, 3. 

 Sonora: Santa Cruz River, 8. 



iThe original label bears the name F. Robinette, but in the original description A. D. Meed was given 

 as the collector. 



