OF THE MALAYAN REGION. 23 
The genera Ornithoptera and Leptocircus are highly characteristic of Malayan ento- 
mology, but are uniform in character and of smallextent. The genus Papilio, on the other 
hand, presents a great variety of forms, and is so richly represented in the Malay islands, 
that more than one-fourth of all the known species are found there. It becomes ne- 
cessary, therefore, to divide this genus into natural groups before we can successfully 
study its geographical distribution. 
Owing principally to Dr. Horsfield's observations in Java, we are acquainted with a 
considerable number of the larvæ of Papilios; and these furnish good characters for the 
primary division of the genus into natural groups. The manner in which the hinder 
wings are plaited or folded back at the abdominal margin, the size of the anal valves, the 
structure of the antennæ, and the form of the wings are also of much service, as well 
as the character of the flight and the style of coloration. Using these characters, I 
divide the Malayan Papilios into four sections, and seventeen groups, as follows :— 
Genus ORNITHOPTERA. 
a. Priamus-group. Black and green. b. Pompeus-group. Black and yellow. 
c. Brookeanus-group. 
Genus PAPILIO. 
A. Larvæ short, thick, with numerous fleshy tubercles ; purplish. 
a. Noz-group. Abdominal fold in g very large ; anal valves small, but swollen ; antennæ mode- 
rate; wings entire, or tailed: includes the Indian Philoxenus-group. 
b. Coon-group. Abdominal fold in 4 small; anal valves small, but swollen; antennz moderate ; 
wings tailed. 
c. Polydorus-group. Abdominal fold in g small, or none; anal valves small or obsolete, hairy ; 
wings tailed or entire. 
B. Larvæ with third segment swollen, transversely or obliquely banded ; pupa much bent. Imago with 
abdominal margin in & plaited, but not reflexed; body weak ; antennæ long; wings much 
dilated, often tailed. d. Ulysses-group. 
e. Peranthus-group. | Protenor-group (Indian) is somewhat intermediate between these, and is 
f. Memnon-group. | nearest to the Noz-group. 
g. Helenus-group. h. Erectheus-group. 
i. Pammon-group. k. Demolion-group. 
C. Larvæ subcylindrical, variously coloured. Imago with abdominal margin in d plaited, but not 
reflexed ; body weak ; antennæ short, with a thick curved club ; wings entire. 
l. Erithonius-group. Sexes alike, larva and pupa something like those of P. Demolion. 
m. Paradoza-group. Sexes different. 
n. Dissimilis-group. Sexes alike; larva bright-coloured; pupa straight, cylindric. 
D. Larvæ elongate, attenuate behind, and often bifid, with lateral and oblique pale stripes, green. 
Imago with the abdominal margin in d reflexed, woolly or hairy within; anal valves small, 
hairy; antennæ short, stout ; body stout. 
o. Macareus-group. Hind wings entire. 
p. Antiphates-group. Hind wings much tailed (swallow-tails). 
q. Eurypylus-group. Hind wings elongate or tailed. 
Genus Lerrocircvs. ; 
making, in all, twenty distinct groups of Malayan Papilionidæ. 
The first section of the genus Papilio (A) comprises insects which, though differing 
considerably in structure, have much general resemblance. They all have a weak, low 
