Lepidoptera of Sikkim. 829 
Melanitis zitenius. 
Papilio zitenius, Herbst, Nat. Schmett., vii., p. 5, 
t. elxxxin., 1.,.2°(1776).; Butt. Ind: i3qni25s8. 
Melanitis zitenius, Dist., Rhop. Mal., p. 412, t. xxxviil., 
2.5, (1886). 
This occurs in Sikkim commonly from April to 
November. 
Melanitis duryodana. 
Melamtis duryodana, Feld., Reise Nov., iii., p. 464 
(1867) ; Butt. Ind., 1., 257. 
Recorded by Moller in the autumn months only from 
September to November, but occurred in 1887 in March. 
Melanitis aswa. 
Melanitis aswa, Moore, P.Z.8., 1865, p. 769; Butt. 
Ind., i. p. 258. 
This form varies more or less in shape and markings, 
and is found at the same elevations as the preceding 
three from 2 to 4000 ft. from April to November. I have 
only taken it at Mongpo in August. Mller is inclined 
to regard this as the wet-season form of duryodana. 
I have tried in vain to separate the species by the key 
to the genus given in the ‘ Butterflies of India,’ but I 
find that, though picked specimens may be separated, 
there remain a number of others which combine some 
of the characters of the different forms in a greater or 
less degree. Neither size, shape, or markings on either 
side have any constancy, and some of the forms seem 
to be present in almost all the localities of the Eastern 
Himalaya, as Assam and Tenasserim, where collections 
have been made. If any one can show that any of these 
forms can be defined by any fixed characters, however 
trifling, or that any characters exist in them which are 
only found in specimens from particular districts, or 
taken at a particular season, I shall be very ready to 
recognise them. Until then I think it is better to keep 
them together, as there is certainly less difference 
between some specimens of aswa and leda, or of ismene 
and duryodana, than there is between leda and ismene, 
which are proved to be one. 
