1920] Howell: A Studxj of the California Jumping Mice 235 



to the underparts is merely a fortuitous stain. Average measure- 

 ments, in the flesh, of 10 apparently adult individuals from South 

 Yolla Bolly Mountain, Tehama County : length, 231.6 mm. ; tail, 139.4 ; 

 foot, 33.2. 



Although there is apparently not the slightest climatic or topo- 

 graphical barrier between the type locality in Eldorado County, of 

 alleni, and the Sierras to the south of it, specimens from the Yosemite 

 region are not at all typical; and, what proves disconcerting, they 

 vary slightly towards pacificus in some respects, having a narrow 

 brain-case and incisive foramina, large bullae, and small pterygoid 

 fossae. Average measurements, in the flesh, of 18 apparently adult 

 specimens from the Yosemite National Park : length, 227.4 mm. ; tail, 

 136.5 ; foot, 32.4. 



Still another variant is found in the Sierras of Tulare County, 

 which is closer to typical alleni as far as small bullae are concerned, 

 but the incisive foramina are even narrower than in Yosemite 

 examples. The pterygoid fossae are very small, the pterygoid plates 

 short, and the rostrum rather short and tapering, with the nasals of 

 equal width throughout, as in pacificus. Average measurements, in 

 the flesh, of 5 apparently adult specimens from the mountains of 

 Tulare County : length, 220 mm. ; tail, 132.4 ; foot, 31.2. 



All the cranial differences of the specimens from these several 

 regions are rather subtle, but unmistakable in series. It might be 

 justifiable, to recognize subspecifically one or another of these variants, 

 but that could hardly be done without naming at least one, and prob- 

 ably two other divisions of alleni, which would then be subspecies 

 of pacificus. Such a course of action would be eminently out of place 

 until suites from a large number of intermediate points are available, 

 and skins of Z. p. pacificus are more numerous. 



Zapus major Preble 

 Warner Mountain Jumping Mouse 



Zapus major Preble (1899, pp. 24-25). 

 Type.—Fem&le adult; no. 79983, Bur. Biol. Surv. ; Warner Mountains, Oregon; 

 August 4, 1896; collected by C. H. Merriam and V. Bailey; original no. 5720 (^de 

 Preble, 1899, pi. 42). 



Eancje.—Yi.\^\ Transition and Boreal zones in the Warner Moun- 

 tains of Modoc County, California, from Lassen Creek south to War- 

 ren Peak. Number of specimens examined, 30, from the following 



