90 



Sierra Club Bulletin. 



this explanation of the habit, for the only creatures whose pur- 

 suit would thus be rendered unusually difficult are human but- 

 terfly chasers, and, surely, there are not enough of them on Mt. 

 Washington, nor have been in ancient times, to lead to the 

 ehmination of the along-slope flyers and thus to the establish- 

 ment, by selection, of the other type. About the only actively 

 pursuing enemies of the Chionobas are the few high-flying 

 birds, and they can fly as well up and down slope as along it. 



Chionobas, like Erebia, will drop down into a crevice between 

 rocks to escape when closely pressed. The under sides of the 

 wings are mottled and marbled in dull color tone, and Scudder 

 noted that semidea has the habit of tumbling on one side with 

 a sudden fall, as soon as it alights, thus especially exposing the 

 under sides of the wings with their mottled markings next the 

 gray rock mottled with brown and yellow lichens. It is an 

 obvious case of protective resemblance, with a special habit to 

 aid the color pattern to become effective as a concealment. 



Another strictly mountain summit California butterfly is 

 Papilio indra, one of the swallow-tails. It is one without much 

 tail, and with no very great size or brilliancy of appearance. 

 The wings, which expand only about two and one-half inches, 

 are dark velvet brown with two broken yellow bands across 

 each one. These bands, one very near the margin and one 

 farther in, are made of separate small yellow blotches, those in 

 the marginal series being much smaller and more widely 

 separated than those in the inner series, and the marginal band 

 itself thus much more broken than the sub-marginal one. I 

 have never seen this adventurous swallow-tail alive, although 

 I have looked closely for it on many peaks and especially on the 

 top of Mt. Tallac, reputed to be one of its favorite resorts. 



The veteran butterfly collector Wright says that it is at home 

 on sharp rocky peaks of 10,000 to 12,000 feet in height, never 

 coming down the mountainsides lower than 9000 feet. "It is 

 peculiar in its habits as well as in its habitat," he writes, "in that 

 while most Papilios are good feeders, Indra spends its time on 

 those high, bare rocks in sunning itself when the sun shines, 

 and in occasionally starting up energetically to flirt with or to 

 fight some other butterfly, but never wasting any time in feed- 

 ing on flowers to prolong its Hfe. 



