376 JOURNAL, BOMBAY NATURAL HISTORY SOCIETY, Vol. IX. 



long, more than half the length of the costa of the forewing, with an 

 elongated slender club, the terminal crook short. Palpi erect, second 

 joint densely hairy ; third joint naked, bluntly conical, standing out 

 prominently from the second joint. Thokax rather stout. Abdomen 

 slender, reaching to the anal angle of the hindwing. Legs, hindleg, 

 femur fringed throughout its length, not tufted ; tibia with a tuft of 

 hairs attached to its proximal and two pairs of spines on its distal end. 

 Female. Differs from the male only in the wings being broader, and 

 lacking the sexual brand on the^forewing. Type, " Baoris " unicolor, 

 Distant. 



Idmon is apparently nearest to Amelia, Watson, but differs entirely 

 in the male secondary sexual characters, the male of A. atkinsoni, Moore, 

 the type of Arnetta, having the inner margin of the forewing lobed, 

 with a tuft of long setse attached to the lobed portion, while I. unicolor, 

 Distant, has the inner margin to the forewing straight, with no 

 tuft of hairs, but has instead a narrow raised brand of modified 

 scales lying alongside a portion of the submedian nervure towards 

 its base on the upperside of the forewing. The shape of the 

 wings in the males of the two typical species of the two genera is very 

 similar, but Idmon has the second median nervule of the forewing 

 arising nearer to the lower end of the discoidal cell, while the first 

 median nervule arises much nearer the base of the wing than in 

 Arnetta ; and the discoidal nervule of the hindwing is quite wanting in 

 Idmon, while it is present in Arnetta. Idmon is more distantly related to 

 Itys, de Niceville, but the shape of the wings and the palpi will readily 

 distinguish between them. The male glandular streak on the upperside 

 of the forewing is almost exactly similar to that found in some species of 

 the otherwise very different genus JPadraona, Moore. I am persuaded 

 that the genus is a valid one, and can give no more convincing reason 

 for the fact that it is quite distinct from Arnetta than the postulate 

 laid down by Captain E. Y. Watson in Proc. Zool. Soc. Lond., 

 1893, p. 6, quoted below, with which I cordially agree : — " In any 

 particular genus in which male secondary sexual characters are 

 found, the particular male character (be it costal fold, discal stigma, 

 or tuft of hairs) may be present or absent in different species of 

 that same genus, but is never replaced by a character of different 

 structure." - 



