1915.] 



THOMOMYS PERPALLIDUS GEOUP. 



75 



17; zygomatic breadth, 27; mastoid breadth, 22; interorbital breadth, 

 7; alveolar length of upper molar series, 9. 



Remarks. — The subspecies aureus is an Upper and Lower Sonoran 

 desert form occupying the bottoms of open sandy valleys, many of 

 which are separated by mountainous or rough country in which the 

 subspecies does not occur. In almost every valley slight variations 

 of characters can be detected, but in none do they become so marked 

 as to require recognition by name. In eastern California this form 

 grades into the smaller 'perjpes, which is mainly Upper Sonoran in 

 range, while aureus occupies the Lower Sonoran valleys. On the 

 south it evidently grades into alhatus along the Colorado River bot- 

 toms, and thence into perpallidus of the Colorado Desert. Two speci- 

 mens from Wickenburg, Ariz., are referred with some hesitation to 

 aureus. Series of specimens from Manti and the Pine VaUey Moun- 

 tains, Utah, are by no means typical but may be called aureus rather 

 than perpes. In New Mexico the subspecies reappears in the Rio 

 Grande Valley from Bernalillo to San Marcial, and while growing 

 darker to the southward is perfectly typical of aureus at Albuquerque. 



Specimens examined. — Total number, 306, as f oUows : 



Arizona: Chin Lee, 2; Jacobs Pool, 4; Keams Canyon, 6; Parker, 16; "Wicken- 

 burg, 2. 



California: Amargosa River (near Nevada line), 3. 



Colorado: Ashbaugh Ranch, 1; Coventry, 8; Grand Junction, 1; Los Pinos, 1; 

 Mesa Verde, 1. 



Nevada: Ash Meadows, 51; Charleston Mountains (east base), 4; Colorado River 

 (head of Black Canyon), 1; Oasis Valley, 3; Pahranagat Valley, 1; Pahrump 

 Valley, 23; St. Thomas, 5; Vegas Valley, 10. 



New Mexico: Acoma, 2; Albuquerque, 4; Bear Spring Mountains, 6; Belen, 6; 

 Bernalillo, 4; Chusca Mountains (west slope), 1; El Vado (Chama River 

 Valley), 1; Fruitland, 4; Gallina (Chama River Valley), 1; Gallup, 2; 

 Juan Tofoya, 2; Laguna, 4; Riley, 4; San Augustine Plain (12 miles north- 

 west of Monica Spring), 6; San Marcial, 5; Shiprock, 2; Socorro, 13; Win- 

 gate, 1. 



Utah: Bluff (San Juan County), 48; Hanksville, 6; Hebron, 1; Henry Moun- 

 tains, 3; Kanab, 4; Manti, 13; Mountain Meadows, 2; Pine Valley, 4; Pine 

 Valley Mountains, 7; St. George, 5; Santa Clara, 2. 



THOMOMYS PERPALLIDUS APACHE Bailey. 

 JiCARiLLA Pocket Gopher. 



(PI. IV, fig. 6.) 



Thomomys apache Bailey, Proc. Biol. Soc. Washington, XXIII, 79, May 4, 1910. 



T^pe.— Collected at Lake La Jara (7,500 feet altitude) on the 

 JicariUa Apache Indian Reservation, N. Mex., by James H. Gaut, 

 September 19, 1904. Type specimen in U. S. Nat. Mus., Biological 

 Survey collection. 



Distribution. — Transition Zone in northeastern Arizona, north- 

 western New Mexico, and southwestern Colorado (fig. 7). 



Characters. — Size large, hind foot 33-34 mm.; color dark; hind 

 feet and tip of tail conspicuously white; mammae in 4 pairs. 



