262 Univcrslfii of Calif or nia Fuhlications in Zoology. [Vol. 7 



may be responsible for the di mi nut ion in numbers of g^ophers 

 the two species of weasels, Putorius arizo)i( itsis and Putonas 

 cicognaui, should be mentioned. It is not improbable that the 

 larger weasel can handle a gopher of almost any size, while the 

 smaller species may prey upon the young ones. It is impossible, 

 however, to state with certainty the exact cause of the apparent 

 dying-out of the species on the western side of the mountains 

 and on many of the high meadows. 



Thomomys nevadensis C. H. ]\Ierriam. 

 Nevada Pocket Gopher. 



Status. — All the specimens secured exhibit the lighter or 

 buffy-gray phase of coloration, called by C. Hart ^lerriam 

 (1897b, p. 213) the "normal" pelage. The dark color around 

 the mouth varies from dusky to a burnt sienna or chestnut. The 

 fur of the throat is white, the patch varying in extent in different 

 specimens. One example (no. 7860) has a white spot in the mid- 

 pectoral region. In certain old specimens (nos. 7856 and 7868) 

 the buffy white ends of the hairs of the underparts have worn 

 off, leaving the plumbeous under-fur most in evidence. In no. 

 7856, too, the dorsal surface is very patchy in appearance, due 

 to the same cause. In some places the hair is so thin as to leave 

 the skin exposed. 



Four juvenals (nos. 7858, 7861, 7862, 7865) may be described 

 as follows : Upperparts uniformly buffy-gray, the gray pre- 

 dominating over the buff'; lighter dorsally than the adults; 

 underparts white, the plumbeous bases of the hairs showing 

 through ; a very slight tinge of buffy is shown by one specimen 

 (no. 7862) ; throat pure white; around fore-legs and along sides 

 of neck buffy; dusky around the mouth; fore and liind feet and 

 tail whitish; ear aud small post-aui-icular area prominently 

 dusky. Juvenals may be distiiiguished fi-om adults by the differ- 

 eiici' ill llic cluii'actcr of llic pelage, that of llic young ones being 

 made up of imicli liner bail's than that of the adults. There are 

 compai'atively more of the long hispid hairs on the young ones, 

 though this is not a sui'e criterion in my e\|)ei-ieiice. One very 

 young Juvenal 'no. 7865) ])reseiits some marked variations in 



