21. —— Scottianus, _Feld._ (Ash Islands). 22. Eurycus Cressida, _Fab._ 6. Pacific Islands. 16. Australia. _Catalogue of Malayan_ PAPILIONIDÆ. ORNITHOPTERA (Boisd.). [Illustration: Fig. 1. Anal valves of _O. Amphrisius_. ] The characters in the _larva_ and _pupa_ which have been supposed to distinguish this genus from PAPILIO are erroneous, or at least do not exist in all the species. My own observations on _O. Poseidon_ show that the _larva_ has no “external sheath” to the thoracic tentacles, and that the suspending thread passes round the pupa, and is not “fastened on each side to a silky tubercle.” There remain therefore only the characters of the perfect insect, the most important of which are the anal valves in the male. These are very large, ovate or rounded, coriaceous, and not hairy, and are furnished with projecting points or spines (sometimes very conspicuous) which serve to attach the male more firmly to the female _in copulâ_. In several species I have observed, these points or hooks were buried in the protruded anal gland of the female, and thus effectually prevented the great weight of the insects causing them to separate upon suddenly taking flight. The great strength and size of these insects, the thick texture of their wings, their long curved and stout antennæ, their peculiar form, colour, and distribution, are the only other characters that separate them from _Papilio_. Though these may not perhaps be technically sufficient, I think it advisable and convenient to retain a genus so well known and long established. _Ornithoptera_ is pre-eminently a Malayan genus, seventeen species inhabiting the archipelago, one (_Rhadamanthus_, Bd.) India and China, one (_Darsius_, G. R. Gray) peculiar to Ceylon, one (_Richmondia_, G. R. Gray) North Australia. _O. Victoriæ_, G. R. Gray, from some island east of New Guinea, should probably be included in the Malayan list; and _Æacus_, Felder, from an unknown locality. The following are the well-established Malayan species. a. _Priamus_ group. 1. ORNITHOPTERA PRIAMUS, Linnæus. ♂. _Papilio Priamus_, L.; Cram. Pap. Ex. t. 23. f. A, B; Godart, Enc. Méth. ix. p. 25. _O. Priamus_, Bd. Sp. Gén. Lép. p. 173. ♀. _P. Panthous_, L.; Cram. Pap. Ex. t. 123. f. A, t. 124. f. A. This may be at once distinguished from all the allied species with which it has been often confounded—in the _male_, by the more rounded and deeply scalloped hind wings, with larger black spots and a broader border, the upper wings with no green on the median nervure or its branches, and the sooty patch extending only to the second median nervule; in the _female_, by the very constant and peculiar light olive-brown colour, the absence of any spots in the discoidal cell of the upper wings, and the broad shallow scallops of the hinder margin. _Hab._ Amboyna and Ceram, probably also Bouru (_Wall._).