LYG^NID^. 185 



always the case, some species rest with wings fully expanded or half open to show off 

 the brilliant colouring of the upperside ; their flight is as a rule extremely rapid, so rapid 

 that the eye can scarcely follow them, but the flights are usually short, the species 

 that live in the grass have usually a weak flight. 



Sexual dimorphism is rare. Leech records that Zephyrus japonica, Murray, has 

 four distinct forms of females with many intergrades. We know of none from 

 the Indian region, whereas, on the other hand, seasonal dimorphism seems to be as 

 common as it is in the butterflies of other families. 



In determining a sub-division of this very interesting family and the order in 

 which they and the species they contain should stand, we have had much difficulty. 

 Dr. Moore left a number of notes, but they refer only to individual species, and are 

 under no arrangement whatever ; de Niceville described eighty-two genera and over 

 four hundred species, but he classified no sub-families, contenting himself with only 

 distinguishing certain groups of genera. These agree fairly well with the groups 

 Doherty had previously characterised from the egg alone. In 1884, in his grand work, 

 " Ehopalocera Malayana," Distant proposed a division of the genera into three 

 groups, founded more or less on the presence or absence of tails to the hindwings, 

 but this system of grouping cannot hold, because there are undoubtedly some genera, 

 such as Arhopala, in which some of the species have tails and some have not. 

 Dr. T. A. Chapman has, however, been working on the genitalia of many Lycsenids, 

 his excellent paper in the Proceedings of the Zoological Society, 1909, part ii. has 

 thrown entirely new light on the subject, and we are attempting to arrange the 

 order of this family in accordance with his views and with those of Mr. J. W. Tutt, in 

 his work on British Butterflies. 



Imago. — Usually of small size, body generally slender, six perfect legs, forelegs 

 somewhat smaller than the others, nearly alike in both sexes, the forelegs in the males 

 furnished with an exarticulate tarsus having several booklets at the tip, distinct from 

 the ungues ; palpi variable in length, often longer in the female than in the male 5 

 antennge generally shorter than half the length of the costa of the forewing, often 

 ringed with white, with an elongated club. Eyes often more or less hairy. Forewing 

 with two or three branches to the sub-costal vein, rarely four, vein 8 absent in all 

 but three genera in the Indian forms, and in the females but not the males of three 

 others, discoidal cell closed, generally narrow, owing to the distance between the 

 costal and sub-costal nervures, wing rather broad and short, the apex and hinder 

 angle well marked, seldom rounded. Hindwing with the outer margin often furnished 

 with one or more slender tails near the anal angle, precostal nervure absent, discoidal 

 cell closed by very slender nervules. 



Eggs hard, small, numerous, much wider than high, reticulate, with a whitish 

 accretion, forming an asymmetrical network of tetragons (Doherty). 



VOL. VII. 2 B 



