366 LEPIDOPTERA CHAP. 



riiipty skin, and by a series of contortions similar to those made 

 by an Insect in depositing an egg, it soon re-attached its anal 

 segment or cremaster to the wel), throwing away the cast-off skin 

 by wriggling its body about." 



Series II. Heterocera. Moths. 



Although Rhopalocera if exclusion be made of the Hes- 

 periidae is probably a natural group, yet this is not the case 

 with Heterocera. The only definition that can be given of 

 Heterocera is the practical one that all Lepidoptera that are not 

 butterflies are Heterocera,. Numerous divisions of the Heterocera 

 have been long current, but their limits have become more and 

 more uncertain, so that at the present time no divisions of greater 

 value than the family command a recognition at all general. This 

 is not really a matter of reproach, for it arises from the desire to 

 recognise only groups that are capable of satisfactory definition. 



Several attempts have recently been made to form a rough 

 forecast of the future classification of moths. Professor Comstock, 

 struck by some peculiarities presented by the Hepialidae, Mierop- 

 terygidae (and Eriocephalidae), recently proposed to separate them 

 from all other Lepidoptera as a sub-order Jugatae. Comstock's 

 discrimination in making this separation met with general ap- 

 proval. The character on which the group Jugatae is based is, 

 however, comparatively trivial, and its possession is not suffi- 

 cient, as pointed out by Packard, 1 to justify the close association 

 of Hepialidae and Micropterygidae, which, in certain important 

 respects, are the most dissimilar of moths. The characters 

 possessed by the two families in common may be summarised by 

 saying that the wings and wing-bearing segments remain in a 

 low stage of development. In nearly all other characters the 

 two families are widely different. Packard has therefore, while 

 accepting Comstock's separation of the families in question, 

 proposed a different combination. He considers that Eriocepha- 

 lidae should l)e separated from all others as " Protolepidoptera " 

 or " Lepidoptera Laciniata," while the whole of the other Lepi- 

 doptera, comprised under the term "Lepidoptera Haustellata," 

 are divided into Palaeolepidoptera (consisting only of Microp- 

 terygidae) and jSTeolepidoptera, comprising all Lepidoptera (in- 



1 Mem. Ac. Jl / '(is.'iingtun, vii. 1895, p. 57. 



