76 



NORTH AMERICAN FAUNA. 



[no. 39. 



Color. — Upper and under parts nearly uniform dull sooty gray 

 slightly washed with dull ochraceous; back with an ill-defined stripe 

 of blackish from tip of nose to base of tail; basal haK to three-quar- 

 ters of tail brownish or blackish, the rest abruptly white; hind feet 

 white; lips usually and chin rarely white. Young: One half-grown 

 individual is lighter, more buffy, with white belly. 



SJcull. — Similar in form and general characters to that of aureus; 

 bullae full and rounded; pterygoids U-shaped, with spicule point of 

 palatal ridge; nasals normally slightly emarginate with doubly 

 rounded posterior tips, instead of normally truncate as in aureus, 

 or widely emarginate as mfulvus. Dentition: Upper incisors white- 

 tipped and decurved at nearly right angles to axis of skuU. 



Measurements. — Type ad.): Total length, 229; tail vertebrae, 

 74; hind foot, 34. fopotype ( ? ad.): 229, 74, 33. Slull (of type): 

 Basal length, 41; nasals, 14; zygomatic breadth, 28; mastoid 

 breadth, 23; alveolar length of upper molar series, 8.5. 



Remarlcs. — ^This is a large, dark form of the perpallidus group with 

 conspicuous markings, but with cranial characters close to those of 

 aureus. It seems to be a dark local Transition Zone form of the 

 yeUow aureus of the surrounding v alleys. 



Specimens examined. — Total number, 36, as follows: 



Arizona: Canyon de Chelly (7 miles above mouth), 1; Fort Defiance (sawmill 



12 miles northwest), 2. 

 Colorado: Arboles, 1; Bayfield, 1. 



New Mexico: Boulder Lake, 4; ^ Chama River (near Gallina), 1 (not typical); 

 Chusca Mountains (around lakes at top of range, 8.000-9,000 feet altitude), 13; 

 Lake La Jara, 2; ^ Stinking Lakes, 11.^ 



THOMOMYS CABEZON^ Merriam. 

 Cabezon Pocket Gopher. 



(PL V, fig. 8.) 



Thomomys cabezonx Merriam, Proc. Biol. Soc. Washington, XIV, 110, July 19, 1901. 



Type. — Collected at Cabezon, San Gorgonio Pass, California, by 

 Clark P. Streator, June 3, 1893. Type specimen in U. S. Nat. Mus., 

 Biological Survey collection. 



Distrihution. — San Gorgonio Pass, southern California, south to 

 Cabezon (fig. 6). 



Characters. — Size medium, hind foot 30 mm.; ears rather large; 

 color dull ochraceous; skull long and narrow. 



Color. — Summer pelage: Upperparts dull ochraceous, varying from 

 buffy ochraceous to dull brownish; ear patch black; nose and lips 

 dusky or plumbeous; underparts creamy white to buffy or salmon. 

 In 8 of 10 topotypes collected in June, a paler, more buffy gray 

 pelage (probably winter) is disappearing on the rump. 



1 On the Jicarilla Apache Indian Reservation ia northern New Mexico. 



