Vol. IX] TAYLOR— COOPER'S MAMMALS 103 



This specimen is an immature molting- from the soft pelage 

 of the adolescent into a bright summer pelage. Its coloration 

 is well within the range of variation of Thomomys hottce pal- 

 lescens. Identified by Vernon Bailey of the U. S. Biological 

 Survey. 



Thomomys monticola monticola Allen 



''T[homomys'\ horealis" (probably part), Cooper, Zoology, 

 in Cronise, The Natural Wealth of California, 1868, p. 446 

 (Said to be found northward and on the mountains). 



Specimen examined. — One : No. 145272, U. S. Nat. Mus. ; 

 obverse of label "1125 Thomomys Summit Johnson's Pass" 

 Sept. 25 '63 J. G. C"; reverse, nine measurements. 



Specimen prepared as usual, skull inside skin ; fore feet bent 

 back, hind feet folded forward beneath body; tail not skinned 

 out, disposed straight out behind. 



The coloration of this specimen is identical with that of a 

 series of topotypes in the collection of the U. S. Biological 

 Survey. 



Thomomys perpallidus mohavensis Grinnell 



"Thomomys umbrinus" (part), Cooper, Proc. Cal. Acad. 

 Nat. Sci., 2, 1861, p. 121 (Said to occur in the "Mojave river 

 bottoms and Cajon Pass") ; Amer. Nat., 3, 1869, p. 183 

 (Southern California). 



"T\^liomoinys'\ iimhrinus" (part), Cooper, Zoology, in 

 Cronise, The Natural Wealth of California, 1868, p. 446 

 ("found in the southeast quarter [of the state]"). 



Specimen examined. — One : No. 5845, Univ. Calif. Mus. 

 Vert. Zool. ; original label missing; label from old University 

 collection reads "No. 254, Thomomys umbrinus? 6 Bottom 

 land MojaveR. June." 



Skull left within the skin ; fore legs crossed on breast, hind 

 feet crossed at base of tail ; tail not skinned ; abdomen not sewed 

 up ; in fairly good condition. 



This animal is evidently an immature ; it is molting conspic- 

 uously from a pale to a much browner pelage. 



"Johnson's Pass: El Dorado County, California (see Whitney's Map of California 

 and Nevada, State Geological Survey of California, 2nd ed., 1874), about eight miles 

 south of the south end of Lake Tahoe, at the head of the South Fork of the Ameri- 

 can River between Lake Valley and Phillips (see Pyramid Peak Sheet, U. S. Geo- 

 logical Survey, Topographic Map of the United States, 1905). 



