Proceedings, 1915. 107 



ever to the more specialized superfamilies that have risen from the stirps, 

 of which these are now the lowest representatives. 



" 2. The Frcniihtm. — Chapman has pointed out that one of the 

 superfamilies (Jlicropterygids) placed with the Jugatse has also dis- 

 tinct traces of a connecting frenulum in the development of some strong 

 hairs ; whilst Kellogg finds, in the Trichopterygid genus Hallesus, ' the 

 beginning of the frenate method of wing-tying,' there being ' present on 

 the base of the costal margin of the hind-wing two long, strong hairs, the 

 ver\- counterpart of the generalized frenulum (i.e., frenulum in which the 

 hairs are not united into one single strong spine) of the lepidopterous 

 wing.' That the frenulum had its origin much lower than is usually 

 assumed, e.g"., in Trichoptera, and. therefore, probably in Lepidoptera, 

 before they were differentiated as such, leads us to suppose that, pos- 

 sibly in the earlier Lepidoptera (now extinct), many frenate and jugate 

 families, otherwise closely related, ran on side by side. Of the latter 

 only the Micropterygids, Eriocraniids, and Hepialids are left, and these, 

 although retaining this primitive trait, have become greatly modified in 

 other directions. 



" 3. Xciiration. — It is now generally accepted that the most gener- 

 alized superfamilies exhibit the most complicated system of neuration, 

 and that the more reduced in number the nervures become, the more 

 specialized is the family, superfamily. etc. This with certain limitations 

 we consider to be generally true. The neuration of the Micropterygids 

 (Eriocephalids), Eriocraniids, and Hepialids is perhaps more generalized 

 than that of any other Lepidoptera. Broadly, on these lines, the neura- 

 tion allows us to separate the more generalized from the more specialized 

 superfamilies. When, however, one comes to detail — i.e., to the consid- 

 eration of the characters arising from the modification of the neuration 

 — we find the characters to be so variously interpreted and applied by 

 different authors that, standing alone, the neurational characters appear 

 to be of very little value. 



" 4. Mozvblc Incisions of Pupa. — Chapman's pupal characters of 

 movable segments divide off sharply, and with definiteness, the general- 

 ized from the specialized superfamilies — the Incompletje representing the 

 former, the Obtectas the latter ; but it is only in the details such as those 

 of the dorsal head-piece, the maxillary palpi, etc., that we get any clue 

 to the real relationships of the superfamilies to one another, although 

 the amount of incompleteness of the pupa (i.e., the actual number of 

 movable segments) affords, in a comparative sense, valuable aid. 



" 3. Hooks on Prologs. — The arrangement of the hooks on the larval 

 ])rolegs is largely associated with a concealed or exposed habit of life, 

 yet, with scarcely an exception, the character is sound in separating the 

 generalized from the specialized superfamilies, and it i;; remarkable that 

 even when a species belonging to one of the specialized superfamilies 

 reverts to a concealed mode of life, the prolegs do not revert to the 

 generalized, but maintain the specialized proleg structure. 



