1038 THE BUTTERFLIES OE NEW ENGLAND. 



leniTtli. Tlie mature caterpillars have a small head and are uniformly 

 cylindrical, slenderer than usual, and almost invariably sparsely pilose, 

 with very short hairs ; some exotic species have long, scattered hairs. 



They feed exclusively on polypetalous plants and almost wholly on 

 Lesjuminosae and Crucifcrao ; sometimes the neirjliborin"' families are 

 selected. They are generally solitary, or at most, where the eggs are laid 

 in open clusters, as in Mancipium brassicae, semigregarious. But there 

 are others which are strictly social, such as Aporia crataegi of Europe, 

 where the caterpillar lives in company beneath a web spread over the haw- 

 thorn bushes ; and a Mexican species, Eucheira socialis, found at an ele- 

 vation of 3200 metres above the sea, whei'e the nest, as described by 

 Humboldt and Westwood, is eight inches long, and made of tougli layers 

 of parcliment-like silk, which Humboldt says can be used as writing paper, 

 and indeed was used as such by the early Spanish fathers ; it is suspended 

 from a tree and has a hole in the bottom for the entrance and exit of the 

 caterpillars ; within this sac they undergo their transformations, and being 

 thus protected the chrysalids are attached to the inner walls by their hinder 

 extremity only, having no need of the supporting girth that is otherwise 

 invariably used througliout this family. Mr. Auguste Salle opened a nest 

 wiiich he brought to Paris from Mexico, and showed me the chrysalis 

 skins iianging in profusion, just as they are depicted in Professor West- 

 wood's plate ; there was certainly no sign of a girth. Rambur (Faune 

 ent. Andal., 249) says that the caterpillar of Zegris eupheme spins a sort 

 of strong gauze envelope, within which the chrysalis hangs b}' its hinder 

 extremity and is further supported l)y an almost invisible band around the 

 body . 



The chrysalids may be distinguished at a glance from all other buttei-fly 

 pupae (excepting some Libytheinae and Hesperidae) by the presence of a 

 single pointed projection in front ; sometimes this is excessively long, 

 often curved upward, and occasionally, as in the Anthocharidi, the exten- 

 sion of the abdomen forms a similar prolongation at the other extremity, 

 80 that the whole presents an oddly bisymmetrical appearance ; tlie chrys- 

 alis is frequently bent backward and the edges of the wing-cases often pro- 

 ject beneath. Nearly all the chrysalids of this subfamily are I'emarkable 

 for their imitations of the colors of their surroundings, sometimes even of 

 the form of seed-vessels or leaves of the food plant of the caterpillar, and 

 have been the subject of some curious experimentation in this direction, as 

 will be elsewhere descriljed. 



The insects of this subfamily are generally double brooded or polygo- 

 neutic, and may pass the winter in any stage excepting that of the egg. 

 The butterflies live in the open country, — Wallace calls them "open ground 

 butterflies"; and Bates speaks of them as "a conspicuous feature in the 

 fauna of temperate latitudes" ; certainly they are here familiar sights to 

 every one. 



