16. Ornithoptera Brookeana, Wallace.
O. Brookeana, Wall. Proc. Ent. Soc. 1855, p. 104; Hewitson, Ex. Butt. Papilionidæ, i. f. 1. Papilio Trogon, V. Voll. Tijdschrift voor Ent. 1860, p. 69, pl. 6.
Hab. Borneo (Sarawak) (Wall.), Sumatra (Leyden Museum).
Remarks.—I have been in much doubt about the position of this remarkable species, and was for some time inclined to place it among the Papilios. It agrees, however, far better with Ornithoptera in the form and stoutness of the wings, the long stout and curved antennæ, the red collar and patches at the base of the wings beneath, the abdominal fold, and the flight and general appearance. It is powerful on the wing, and occasionally settles on the ground in damp sunny places. It inhabits the interior of North-west Borneo and the mountains of West Sumatra. The female is unknown. It is peculiar in the great length of the discoidal cell of the wings and its altogether unique style of coloration, and must be considered as the type of a distinct group of the genus Ornithoptera.
Papilio.
This is without doubt the finest and most remarkable genus of Diurnal Lepidoptera. About 360 species are now known, all, except ten, being tropical or subtropical. I have given at p. 23 the characters of the sections and groups into which I divide the Malayan species.
Section A.
a. Nox group.
17. Papilio Nox, Swainson.
P. Nox., Sw. Zool. Ill. pl. 102; Horsf. Lep. Ins. E. I. C. pl. 1. f. 1; Boisd. Sp. Gén. Lép. p. 277.