DISTRIBUTION OF PAPILIONIDA IN THE HIMALAYAS. 199 
Himalayas are situated wholly outside the astronomical limits of 
the Tropics (being between 27° 5’ and 28° 10’ north latitude), by 
reason of its sheltered position, equable temperature and super- 
abundant precipitation, the tropical zone is powerfully repre- 
sented in its animal and plant-life, which extends from the 
malarial Terai Jungle and Sal Forest at the foot of the outer 
hills at the low altitude of only about 200 ft. above the sea-level 
to 2500 ft. or thereabouts. To this circumscribed belt the most 
strictly tropical species of butterflies are chiefly confined. Among 
the Papilionide, which are specially characteristic of this zone, 
special mention may be made of the following :—Ornithoptera 
rhadamanthus, Pangerana didoneus, Tamera castor, Menamopsts 
slatert, M. epycides, Isamiopsis teleachus, Paranticopsis megarus, 
P. «wenocles, P. macareus, Pazala glycerion, Pathysa agetes, P. 
antiphates, P. anticrates, Zetides eurypylus, Z. bathycles, Mean- 
drusa evan. While the following, although they belong more 
properly to the fauna of the peninsula, may also be enume- 
rated, namely :—Menelaides aristolochie, Iliades polymnestor, 
Lertias polytes, Orpheides erichthonius, Pathysa nomius, the 
second and fifth of which are only occasional stragglers from 
the plains, and have not been known to perform their metamor- 
phoses within the district under discussion. 
Most of the typical forms of arborescent vegetation extend 
upwards to 5000 ft. or thereabouts, which may be taken to be 
the upper limits of the subtropical zone, between which and the 
one below there is apparently not a great deal of difference 
either in the zoological or the botanical physiognomy, so that 
the fauna and flora are in reality only an extension of the pre- 
ceding, the principal difference consisting in the gradual elimina- 
tion of the strictly tropical element towards the confines of the 
belt above. The majority of the intertropical species of butter- 
flies ascend to various altitudes within this zone, for the most 
part, however, performing their transformations probably below 
4000 ft., though in the imago state some of them may occasion- 
ally be seen considerably higher up the mountain sides, while 
towards the upper limits an entirely new element commences to 
come into existence in the shape of temperate modifications of a 
tropical fauna. 
Between 5000 ft. and 7500 ft. or so the warm-temperate zone 
holds sway with its sombre, dense forests of dark olive-green 
oaks and chestnuts and thick undergrowth of laurels and ferns. 
It is here that some of the most interesting Himalayan Papi- 
lionide have their headquarters, the various species which are 
endemic or nearly so to this particular climatal belt consisting 
exclusively of temperate modifications of tropical forms belong- 
ing to the Indo-Malayan fauna, corresponding to those occurring 
in the more elevated districts of Southern China, most of them, 
indeed, being absolutely identical therewith. The following is a 
