Briefly to summarize these peculiarities, Celebes possesses three genera of mammals (out of the very small number which inhabit it) which are of singular and isolated forms, viz., _Cynopithecus_, a tailless Ape allied to the Baboons; _Anoa_, a straight-horned Antelope of obscure affinities, but quite unlike anything else in the whole archipelago or in India; and _Babirusa_, an altogether abnormal wild Pig. With a rather limited bird population, Celebes has an immense preponderance of species confined to it, and has also five remarkable genera (_Meropogon_, _Streptocitta_, _Enodes_, _Scissirostrum_, and _Megacephalon_) entirely restricted to its narrow limits, as well as two others (_Prioniturus_ and _Basilornis_) which only range to a single island beyond it. Mr. Smith’s elaborate tables of the distribution of Malayan Hymenoptera (see ‘Proc. Linn. Soc.’ Zool. vol. vii.) show that, out of the large number of 301 species collected in Celebes, 190 (or nearly two-thirds) were absolutely restricted to it, although Borneo, on one side, and the various islands of the Moluccas on the other, were equally well explored by me; and no less than twelve of the genera are not found in any other island of the archipelago. I have just shown in the present paper that, in the Papilionidæ, it has far more species of its own than any other island, and a greater proportion of peculiar species than many of the large groups of islands in the archipelago—and that it gives to a large number of the species and varieties which inhabit it, 1st, an increase of size, and, 2nd, a peculiar modification in the form of the wings, which stamp upon the most dissimilar insects a mark distinctive of their common birth-place.