LYcmmDm. 
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 Zephyr us. 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 Malay ana,” 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 Lycaenids, 
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 hooklets at the tip, distinct from 
the ungues; palpi variable in length, often longer in the female than in the male; 
antennae 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 si b-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 
