INSECT'S. 
307 
found, the highest yet recorded for the flight of butterflies. 
Both the genera {Parnassius and Mesapia) are exclusively 
confined to mountain ranges and to the Northern Hemi- 
sphere ; Parnassius occurring (not lower than 1000 ft.) in 
the Pyrenees, the Alps, the Carpathians, the Ural, the Altai, 
and the mountains of East Siberia, Kamtschatka, and 
Japan, and the Himalaya, and in the Sierra Nevada 
and Rocky Mountains of North America; and Mesapia 
being peculiar, so far as at present known, to Western 
Thibet. The geographical distribution of the species of 
Parnassius, of which twenty-five are known, is peculiar in 
so far as, although the insects are never seen in the plains 
between the mountain groups, the species are not strictly 
local in their range : thus Parnassius Apollo, common in 
the Alps, occurs again on the Altai; the same may be said 
of P. Phoebus, and the common species of the Sierra Ne- 
vada of California (C. clodius) can scarcely be considered 
as more than a slight local variety of a species of Middle 
Siberia (C. clarius). The numerous species of the Hima- 
laya, however, are all peculiar to this mountain system, 
and are distinguished from their northern allies by the 
larger amount of coloration in their wings. The Himalayan 
species appear to have their distinct zones of elevation. 
The one which descends lowest into the plains is P. Hard- 
wickii, sent not uncommonly in collections from Simla. 
P. Jacquemontii appears to range rather higher up the 
southern slopes of the Himalaya. Three others — P. CharU 
tonius, P. Simo, and P. Acco — have only as yet been 
recorded from the highest elevations, having been discovered 
by Major Charlton at heights varying from 15,000 to 
16,000 feet in Western Thibet, and one of them again met 
with by Dr. Henderson from 17,000 to 19,690 feet of 
elevation. There can be little doubt that the food-plant 
of their caterpillars grows also in the same zone as the 
perfect insects. 
H. W. Bates. 
X 2 
