FAMILY BRUSH-FOOTED BUTTERFLIES. 103 



segments ; a pair of long, clubbed, and prickly tubercles on 

 second thoracic segment; not more than about twenty minute, 

 smooth warts on any one segment above the spiracles. Length 

 more than 1 inch. 



Chrysalis. — Strangely streaked and blotched with blackish 

 green, yellowish brown, pale salmon, and plumbeous, lightest on 

 the abdomen; tail-piece, viewed from above, twice as long as its 

 apical width. Length nearly 1 inch. 



The eggs, wliicli are globular, pitted, briefly filameutous, 

 and deep green, are laid as in the other species, but 

 occasionally also on the under surface of the leaf, and 

 hatch in from four to eight days. The caterpillar feeds 

 upon various Salicaceae, particularly willow and poplar; its 

 habits are precisely like those of the other species as 

 recorded above, but it is remarkable that, being everywhere 

 at least double-brooded, the caterpillars of the first brood 

 never form hibernacula, so that we have here an instinct 

 inherited only by alternate generations. The chrysalis 

 hangs from seven to ten days. The butterfly lives in the 

 open country and is widespread; as stated above, it is 

 double-brooded, and probably in the Southern States there 

 is a third brood, which may perhaps sometimes appear as 

 a supplementary feeble brood further north. About the 

 latitude of central New England the first butterflies, from 

 the caterpillars which have hibernated in their first or 

 second, rarely their third, stage, appear the first week in 

 June, continue to emerge throughout this month and begin 

 to lay eggs about a fortnight after they first apj)ear; the 

 second brood appears about the middle of July, while many 

 of the butterflies of the first brood are still on the wing; 

 as butterflies are still to be found laying eggs late in 

 August and even in September, there may possibly be a 

 third brood. 



This butterfly has a special interest from its remarkable 

 departure in coloring and pattern from the other species 



