Classification of the Lepidoptera. 257 



separated groups of families : the first section, as a matter of 

 fact, being the Syntomidee, erected as a family first by 

 Herrich-Schaffer in 1845, dominant in America but poorly 

 represented in the Old World, and closely related in the form 

 of larvae and pupa?, as shown by Dr. Chapman, to the 

 Arctiidss ; whilst the second section, the Zygajuidee proper, 

 hardly represented in America but numerous in the Old 

 World, is related, as Dr. Chapman has also shown, to the 

 Limacodidte and the lowest families of the Frenatse ; these 

 relationships of the two families being fully borne out by the 

 structure of the imago. 



One of the many points of interest in Prof. Comstock's 

 paper is his confirmation of the fact that vein 4 is really a 

 part of the three-branched radial nervure, its connexion with 

 the two-branched median nervure being only secondary, as 

 Spuler * first demonstrated from a study of its development. 



The suggestion of the relationship of the Hesperiidas to 

 the Thyrididas is interesting, and is based on the origin of 

 veins 6 to 11 of the fore wing directly from the cell, which 

 is a character common in the lowest Frenatse, such as the 

 Zygajnidaa and Sesiidai. The small Oriental day-flying 

 family — the Callidulida? — akin to the ThyrididaB, has some 

 forms which are so like the Hcsperiidas in flight and general 

 appearance as to be indistinguishable on the wing. In the 

 Callidulida; and Thyrididse, however, vein 5 of the fore wing 

 has migrated to the lower angle of the cell, whilst in the 

 Hesperiidas it arises near the middle of the discocellulars — 

 from slightly above or below — so that it would be from some 

 ancestral form before the migration of vein 5 became fixed, 

 and not from the Callidulidee themselves, that the development 

 took place. Again, in the Thyrididaj and Callidulidte vein 8 

 of the hind wing approaches vein 7 after its origin from the 

 cell, whilst in the Hesperiidas they are widely separate, 

 though in the Callidulid genus Herimba there is an approach 

 to the Hesperid form, this genus being also of iuterest from 

 the retinaculum of the male consisting of a tuft of hair from 

 the median nervure of fore wing, which is the usual female 

 form. In the Hesperiida; also this tuft of hair is often deve- 

 loped, and to a certain extent articulates with rough hair 

 from the costa of the hind wing, possibly representing the 

 primitive form of the frenulum. In other Callidulidaa the 

 frenulum is entirely absent, whilst the Australian Euschemon 

 liafflesia, Westw., is a typical Hesperid in every point of 



* A. Spuler, ' Zur Phylogeuie uud Ontogenie dea Fliigelgeiiders dor 

 Schmetterlinge.' 



