72 THE BUTTERFLIES OF NEW ENGLAND. 



obvious reason whatever. It is w^ell known that as a general rule moths 

 undergo their transformations to chrysalis within a cocoon, spun by the 

 caterpillar, or in a cell moulded beneath the surface of the ground. The 

 same is true of the lowest family, Hesperidae, which usually make such a 

 cocoon within a rolled-up leaf or cluster of leaves, and hence had given 

 them by Boisduval the term Involuti. It was not noted l)y him, nor has 

 it been, as far as we are aware, by any author, though figured by many, 

 that within this cocoon they generally, perhaps always, spin a pair of 

 shrouds, into the middle of one of which they plunge their cremaster, 

 while by the other they support the middle of the body (86:26 ; 87:12). 



Now, remove this outer cocoon and leave the shrouds, and one has, 

 with only such changes as are absolutely required by the lack of the en- 

 circling cocoon, the character of the support of the chrysalis of the Papili- 

 onidae, viz., a button of silk attached to the object from which the 

 chrysalis hangs, and a loose girt around the middle of the body. In the 

 Lycaenidae, we pass simply to a still closer attachment of these fastenings, 

 so that the rounded chrysalis appears almost glued to the surface to which 

 it is attached ; and these two families, the Lycaenidae and the Papilionidae 

 were classed by Boisduval under his Succincti. In the Nymphalidae, by 

 the loss of the median girt the chrysalis hangs suspended by its hinder end, 

 and forms the group termed by Boisduval Suspensi or Penduli, which he 

 and his followers interpose between the Involuti and the Succincti. Yet we 

 have here a regular progression from the cocoon of the moths to the almost 

 total absence of the use of any silk for the quiescent period of life. Even 

 the few exceptions to this rule seem to be entirely explanable as instances 

 of reversion. Thus the only case among the higher butterflies where a 

 cocoon properly speaking is made, is in the subfamilies most closely allied 

 to the Hesperidae, among the group of Parnassidi and Anthocharidi ;* 

 and again in exceedingly feeble instances where the necessities ap})ear to 

 be overwhelmingly great, among some of the higher Nymphalidae, which 

 have lost even the last remnant of the cocoon of moths ; viz., in some of the 

 Satyridae, which lack cremastral hooks and undergo their transformations 

 ordinarily in the rudest form of a cell which they can construct above or at 

 the surface of the ground, by the mere movements of the body and the spin- 

 ning of one or two threads of silk. So, too, there are known to be one or 

 two instances where one of the Nymphalidae is suspended so firmly by its 

 cremastral hooks as to hold the chrysalis in a rigid oblique position very 

 akin to that of the Lycaenidae, but without the aid of the median girt ; 

 and as a forerunner of the "suspended" condition, one or two of the 

 Lemoniinae, species of Stalachtis and Emesis, are stated by Bates to have 

 an entirely similar mode of pupation. Again, anotlier of the Nymphalidae, 

 Ageronia, is said by Lacordaire to be supported in part by a median girt 



*Bar asserts that the same is true in some South American Lemoniinae. 



