138 Meri'icnn Xar Ground Squirrels. 



patches whitish, not sharply denned; facial stripes pale; ear 

 stripes indistinct ; legs and feet gray. Tail : upper surface 

 hoary (rarely yellowish), becoming black toward the tip (the 

 individual hairs buffy gray sub-basally, then black, and broadly 

 tipped with pale buffy gra^y or yellowish) ; under surface, pale 

 buffy fulvous, bordered and broadly tipped with black, broadly 

 edged laterally with pale buffy. 



Summer Pelage : Dorsal dark stripes bright ferruginous ; facial 

 stripes strengthened by dull rusty ; flanks bright fulvous, the 

 fulvous -reach ing forward over shoulders to sides of neck. 



Cranial Characters. Skull similar in size and general appear- 

 ance to that of T. minimus pictus, but with longer nasals and 

 nasal branches of premaxillaries. The length of the nasals 

 equals or exceeds the combined length of the basioccipital and 

 basisphenoid. In minimus the nasals fall considerably short of 

 this measurement.* 



General Remarks. The Alpine chipmunk is one of the two 

 smallest chipmunks known, the other being the Sage Plains 

 species (T. minimus), which it resembles in general appearance, 

 except in the full summer pelage. In all pelages it may be dis- 

 tinguished from minimus by the tail, which is hoary above 

 (rarely yellowish) ; is broader and more bushy, and has the 

 black terminal part much longer. The outer pair of white dorsal 

 stripes also are much broader, as in speciosus. In spring and 

 early summer, before the post-breeding molt, the animal is very 

 much paler than the palest specimens of minimus pictus. In 

 midsumer pelage, on the other hand, the sides and dark stripes 

 are deeper ferruginous than ever seen in the brightest summer 

 specimens of minimus pictus or even minimus consobrinus, and in 

 high-colored individuals even the inner pair of light stripes are 

 sometimes obscured by rusty. 



Geographic Distribution. This beautiful little chipmunk is re- 

 stricted, so far as known, to the alpine summits of the High 

 Sierra, where it lives among rocks at timber-line, ranging a little 

 above and a little below the upper limit of tree growth. Thus 

 the haunts of the alpine chipmunk are the same as those of the 

 pika (Lagomys'), the alpine marmot (Arctomys fl&viventer), and 

 the mountain sheep (Ocis canadensis). No mammal ranges 

 higher. Sixty specimens were obtained by the Death Valley 

 Expedition. 



*This has been verified in 100 skulls, 50 of 7/>//m.y and 50 of 

 and subspecies. 



