EASTERN UNITED STATES. 23 



moult, when they close every place of egress and pass 

 the winter in the web. In the spring they leave the web 

 and bask in the sunshine on the leaves. 



THE CHRYSALIS, OR PUPA. 



When ready to change to a chrysalis, the larva seeks 

 some retreat, if it be one of the species that does not 

 pupate in a web or a cluster of leaves, where it prepares 

 to change to the pupal or quiescent period. In the 

 Papilionidse and Lycsenidae this preparation consists in 

 spinning a button of silk on the under side, or side, of 

 some object, within which it entangles the hooks of the 

 anal feet. Then a loop of silk is woven from side to 

 side that will support the body a little in front of the 

 middle, in which the body is allowed to rest, held in 

 place by the anal feet. Soon the skin is shed, and the 

 chiysalis appears limp and pale, but as the moisture is 

 evaporated the outside hardens, and it assumes a shape 

 and color peculiar to the species. In others, as the 

 Nymphalid^e, the button of silk is spun and the anal 

 feet are entangled in it, but the front part of the body 

 hangs down without the loop of silk to support it. 

 The anterior part bends like a fish-hook, after which 

 the skin is shed and the chrysalis suspended by the anal 

 hooks. 



In the larva there was but little distinction of parts, 

 as head, thorax, and abdomen. In the chrysalis there is 

 more of a division of these parts, the head and thorax 

 being united, but the abdomen readily separable. 



In moths the head part of the chrysalis is usually 

 rounded, but in butterflies, especially some of the large 

 Papilios, the cephalo-thora x bears several prominences 



