66 



NORTH AMEEICAN FAUNA. 



[no. 35 



Color. — July pelage, in which 3 molts are shown: Upperparts dark 

 gray produced by a heavy mixture of black-tipped hairs over dull 

 ocliraceous; nose, face, and ear patch blackish; tail gray; feet whitish; 

 underparts dull buffy. 



S'kull. — Adult males: Long and narrow, with narrow braincase; 

 nasals and rostrum long and straight; zygomatic arches slender; 

 bullae small and especially short and rounded; interparietal small and 

 triangular. 



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

 77; hind foot, 32 (measured dry). Topotype ( c? ad.): 206, 64, 31. 

 Female topotype: 211, 65, 31. S'kull {oi type): Basal length, 37; 

 nasals, 14.5; zygomatic breadth, 24; mastoid breadth, 19.5: inter- 

 orbital breadth, 6; alveolar length of upper molar series, 7.5. 



Remarks. — Externally this species differs very little from altivallis 

 of the San Bernardino Mountains, but the skulls show such striking 

 differences that the two forms can not be considered closely related. 

 Neither does the present form show any characters of pallescens on 

 the south or of perpes on the north slopes of its range, but appears to 

 approach alpinus and awahnee of the southern Sierra Nevada. Its 

 actual range and real relationship present an interesting problem 

 still to be worked out. 



Specimens examined. — Three, from type locality. 



THOMOMYS .lACINTEUS Grinnell & Swarth. 

 San Jacinto Pocket Gopher. 



(PI. V, fig. 14.) 



Thomomys jacinteus Grinnell & Swarth, Proc. Cal. Acad. Sci., 4th ser., IV, 153-160, 

 Dec. 30, 1914. 



Type. — ^Collected on San Jacinto Mountains (Round Valley, at 

 9,000 feet altitude), California, by H. S. Swarth, September 15, 1914. 

 Type specimen in Mus. Vert. ZooL, Univ. of California. 



Distribution.— -\]])j)eT slopes of San Jacinto Mountains, Cal. (fig. 6). 



Characters. — Size medium, slightly larger than nigricans, much 

 smaller than altivallis, and about the size of martirensis and neglectus; 

 colors dark; skull long and narrow with relatively straight dorsal 

 outline; mammae in 4' pairs. 



Color. — Summer pelage: Upperparts dark rich ochraceous, darkened 

 with black- tipped hairs, darkest along median line of back ; nose dusky ; 

 ears and ear patches black; underparts brighter ochraceous without 

 black-tipped hairs; lining of cheek pouches and usually lips white; 

 base of tail brownish; tip of tail and feet whitish. Winter pelage: 

 More clouded by black above. 



Skull. — Long, low, and narrow, with especially long narrow brain- 

 case; zygomatic arches widest at anterior angle and narrowed pos- 

 teriorly with the narrowing of the braincase; nasals truncate poste- 

 riorly, generally long and narrowly cuneate, but in the type rather 



