506 PAPILIONID.E. 
insects ascend to higher altitudes, whence after pairing the females descend 
again to the breeding-ground to deposit their eggs. This supposition is 
based on my experience of an allied species, P. charltonius, of which I 
captured some numbers in Baltistan, North-west Himalayas. There both 
sexes were disporting themselves about the rugged grassy slopes on the very 
edge of the snow-line. Their flight was exceedingly rapid, and they were 
very difficult to capture, except when at rest on the rocks. In the hot gorges 
some thousands of feet lower I took a few specimens, but they were all 
females. The ground frequented at the higher elevation would be covered 
with snow during the earlier stages of the insect. 
The variation of P. imperator is very similar to tliat of many others of the 
genus. The ocelli on the upper portion of the submarginal area of second- 
aries vary in colour from the deepest crimson to a palish orange, and the 
white centre may be either very large or eutii'ely absent; these ocelli are 
sometimes connected by a black streak. The blue subanal ocelli vary in 
number from two to four, but two is the typical and more usual number. In 
addition to his type of P. imperator, Oberthiir has figured on the same 
plate (fig. 4 c) an aberration with four subanal ocelli. 
Occurs commonly at Ta-chien-lu, and more sparingly at "Wa-shan and Wa- 
ssu-kow in Western China. I have also received specimens from the high 
Thibetan plateau beyond Ta-chien-lu, and most of the males of this species 
that I have came from that locality. Grum-Grshimailo (Horse Soc. Ent. Ross. 
1S91, p. 446) describes a form (var. musgeta) from the Amdo region. 
Parnassius citrinariiis. (Plate XXXIII. figs. 6 d , 5 var. ? .) 
Parnassius citr'niarius, Motscliulsky, Bull. Mosc. xxxix. p. 189 (18G6). 
Parnassius glacialis, Butler, Journ. Linn. Soc, Zool. ix. p. 50 (1866) ; Fryer, Rliop. 
Nihon. p. 5, pi. iii. fig. 5 (1886). 
" Statura Parn. siuhhendorjii, Menetr., sed brevior. Corpora nigro, thorace ventreque dense citrino- 
villosis ; alis subhyalinis, testaceo-albidis, nervis nigris, mediis nigro pulverosis ; alis posticis 
basi nigricantibus." (Motschulsl-i/, L c.) 
P. glacialis, Butler. — " Alae supra subhyalinoe, albte, venis nigris : antico apice byalino : cella 
media faseiata faseiaque brevi terminata, fasoiis cinereis : postieoe margine abdominali late 
nigro : corpus nigrum, thoraee pras ferrugineo : abdomine cincreo pilosato, a latere ferru- 
gineo ; antennae nigrse. 
" Alae subtus nitentes : posticsB margine abdominali cinereo ; aliter vclut supra : corpus nigrum, 
pilis ferrugineis sparsum. 
" Alar, exp, unc. rf-^^^^." {Butler, I. c.) 
