Lepidoptera of Sikkim. 437 
433. Papilio agamemnon. 
Papilio agamemnon, Linn., Mus. Ulr., p. 202 (1764). 
Common up to 8000 ft. from April till December. 
434. Papilio Gyas. 
Papilio Gyas, Westw., Arc. Ent., i., t. xi. (1841). 
_ This is a decidedly rare species in Sikkim. I have 
seen it once only flying round the top of a hill at 
6000 ft. at Rikisum in August. Méller has seen it on 
Birch hill at 7000 ft. in July, and Mr. Knyvett has taken 
the very rare female on Sinchul in August. It seems 
therefore to be a single-brooded species, inhabiting the 
same zone of elevation as most of the peculiar Sikkim 
species do. The female, which has never been described, 
differs very markedly from the male in its pale whitish 
colour above. 
435. Papilio machaon. 
Papilio machaon, L., var. asiatica, Mén., Cat. Mus. 
Petr, .1...p. (0.(1855).5. Elwes, P.Z.S., 1882, 
p. 399, ef. Hagen, Papilio, ii., p. 151 (1882). 
P. Sikkimensis, Moore, J. A. 8. B., 1884, p. 32. 
Neither Méller or myself have ever seen this species 
in British Sikkim, and I believe it only occurs in the 
higher, dryer hills of the interior, whence our native 
skikaris have brought very numerous specimens-in July 
and August. 
The interesting papers on the varieties of this species 
by Prof. Hagen and Mr. W. H. Edwards in Papilio, 
1882 and 1883 show how hard it.is to come to any just 
conclusion as to the variation of wide-ranging species like 
machaon; but I see no reason to alter what I formerly 
said as to the Sikkim form, viz., that itis darker and 
more heavily marked than in Europe, smaller and more 
uniform in co’our thanin Japan. It must be remembered 
that only one brood is found, as far as we know, in the 
Eastern Himalaya, and that at a great elevation, pro- 
bably from 8 or 10 to 12,000 ft. and upwards. 
436. Papilio castor. 
Papilio castor, Westw., Ann. Mag. Nat. Hist., ix., 
p. 87 (1842); Arc. Ent., i1., t. 80 (1848). 
9, PB. pollux, Westw., l.c. 
