NYMPHALID^ 247 



terior segment in such way that it can twist the pupa case 

 around and catch the hook of the pupa case into the web. 

 The pupa case hxsts only a week or ten days and then gives 

 rise to the adult form. It is mimicked by a species which has 

 an additional black band on the hind wing and there are 

 differences in the legs. This, the viceroy (Basilarchia 

 archipjms) has evidently gained protection by taking on 

 the appearance of the monarch. 



One other species in the family Nymphalidce that should 

 be noticed is the common mourning cloak vanessa (Euvan- 

 essa antioya) which is interesting because of its very wide 

 distribution and its very great hardihood. It is said to occur 

 over practically all of the northern hemisphere from 30° to 

 the Arctic Circle. It occurs here in the winter time, hiber- 

 nating as an adult and has been found secreted in hollow 

 logs, bridges, and in almost any sheltered place, and if 

 taken indoors will revive and feed on sweetened water 

 quite readily. They begin to fly quite early in the spring. 

 It is double-brooded — the eggs deposited in early spring 

 produce larvae which mature in midsummer. They breed 

 on willow particularly and the larvae are dark-colored and 

 rather conspicuous. They also infest poplar, elm, and 

 dogwood, but willow seems to be the favorite. The chrysalis 

 is attached to the twigs of these plants and the adults 

 appear in midsummer. These adults deposit eggs and a 

 second generation appears in autumn which hibernates and 

 carries the species o^•er winter. In some places they have 

 an economic importance, but ordinarily they are not a 

 serious pest, and the butterfly is such a handsome species 

 that it may be counted as deserving immunity. 



