THE AUSTRALIAN NATURALIST. 93 
or grouping of closely-related forms, because I have been 
studying them for some time, and I think I will be able to put 
before you facts not only of interest to the Entomologist, but 
to all naturalists, especially those engaged in the study of 
geographical distribution. I will also illustrate by this species 
some of the difficulties with which a systematic Entomologist 
is confronted. 
Tam exhibiting to-night as many forms as I am able to 
bring together to illustrate my remarks, while some of my 
later views will in addition be based on the series of geographi- 
cal variations of T'roides priamus now before you. 
My remarks will fall under the following headings :-—— 
. Life history. 
. History in literature. 
. Variation. 
. Distribution. y 
. New Guinea as a centre of dispersion as exemplified by 
Papilio segeus and Troides priamus. 
1, Life history.—In speaking of the life history of this species 
I must of necessity confine myself to those facts I have 
observed myself. most of which have been obtained in the 
neighbourhood of Sydney. As in Australia this species ranges 
from Cape York to Sydney, and more rarely to the Northern 
portions of Victoria, some of my details may not be strictly 
applicable to other latitudes. 
Ub wir 
The most general food plant of this species during the last 
one hundred years has been the ordinary orchard citrus trees, 
and for that reason the species is popularly known as the large 
black and white orchard butterfly. Before the colonization of 
Australia, this could not have been its food plant, which was 
no doubt the Australian ljme, a plant which occurs north of 
Newcastle, but I have never taken it feeding on this plant. 
Near Sydney I have seen pups in the bush on Zeria levigata, 
and I have heard of larve being found on the same plant. 
Lately I was shown several pups on a plant of Chotsea growing 
in a friend’s garden, which was much eaten, evidently by the 
larve of this species. I exhibit portions of these plants to- 
night, and I believe these as food plants have not yet been 
recorded. ‘The egg is spherical in shape, excepting at its point 
of attachment to the leaf of the food plant, smooth and pale 
lemon green in colour. It is usually laid in the Autumn, and 
before hatching the dark young larva can be seen within the 
ege shell. The young larva is a dark olive brown, usually 
with a whitish bar on either side, and bearing on the back a 
double row of short, fleshy spikes. When nearly full grown 
the larva changes to green with a pinkish white stripe on 
either side. As in all Papilio the larva is provided on the 
