Of the Coleoptera we know much less, but a few interesting facts may be noted. There are a number of fine species of Cicindela, some of peculiar forms; and one Odontochila, a South American genus; while Collyris reaches Celebes from the Oriental region. In Carabidæ it has one peculiar genus, Dicraspeda; and a species of the fine Australian genus Catadromus. In Lucanidæ it has the Oriental genus, Odontolabris. In Cetoniidæ it has a peculiar genus, Sternoplus, and several fine Cetoniæ; but the characteristic Malayan genus, Lomaptera, found in every other island of the archipelago from Sumatra to New Guinea, is absent—an analogous fact to the case of Ceyx among birds. In Buprestidæ, the principal Austro-Malay genus, Sambus, is found here; while Sponsor, a genus 8 species of which inhabit Mauritius, has one species here and one in New Guinea. In Longicorns there are four peculiar genera, Comusia, Pytholia, Bityle, and Ombrosaga; but the most important features are the occurrence of the otherwise purely Indo-Malayan genera Agelasta, Nyctimene, and Astathes; and of the purely Austro-Malayan Arrhenotus, Trysimia, Xenolea, Amblymora, Diallus, and Ægocidnus. The remaining genera range over both portions of the archipelago. In the extensive family of Curculionidæ we can only notice the elegant genus, Celebia, allied to Eupholus, which, owing to its abundance and beauty, is a conspicuous feature in the entomology of the island.
Origin of the fauna of Celebes.—We have now to consider, briefly, what past changes of physical geography are indicated by the curious assemblage of facts here adduced. We have evidently, in Celebes, a remnant of an exceedingly ancient land, which has undergone many and varied revolutions; and the stock of ancient forms which it contains must be taken account of, when we speculate on the causes that have so curiously limited more recent immigrations. Going back to the arrival of those genera which are represented in Celebes by peculiar species, and taking first the Austro-Malay genera, we find among them such groups as Zonœnas (s.g.), Phlogœnas, Leucotreron (s.g.), and Turacœna, which are not found in the Moluccas at all; and Myzomela, found in Timor and Banda, but not in Ceram or Bouru, which are nearest to Celebes. This, combined with the curious absence of so many of the commonest Moluccan genera, leads to the conclusion that the Austro-Malay immigration took place by way of Timor and the southern part of New Guinea. It will be remembered, that to account for the Indo-Malayan forms in New Guinea, we suggested an extension of that country in a westerly direction just north of Timor. Now this is exactly what we require, to account for the stocking of Celebes with the Australian forms it possesses. At this time Borneo did not approach so near, and it was at a somewhat later period that the last great Indo-Malay migration set in; but finding the country already fairly stocked, comparatively few groups were able to establish themselves.
Going back a little farther, we come to the entrance of those few birds and insects which belong to India or Indo-China; and this probably occurred at the same time as that continental extension southward, which we found was required to account for a similar phenomenon in Java. Celebes, being more remote, received only a few stragglers. We have now to go much farther back, to the time when the ancestors of the peculiar Celebesian genera entered the country, and here our conjectures must necessarily be less defined.
On the Australian side we have to account for Megacephalon, and the other genera of purely Papuan type. It may perhaps be sufficient to say, that we do not yet know that these genera, or some very close allies, do not still exist in New Guinea; in which case they may well have entered at the same time with the species, already referred to. If, on the other hand, they are really as isolated as they appear to be, they represent an earlier communication, either by an approximation of the two islands over the space now occupied by the Moluccas; or, what is perhaps more probable, through a former extension of the Moluccas, which have since undergone so much subsidence, as to lead to the extinction of a large proportion of their ancient fauna. The wide-spread volcanic action, and especially the prevalence of raised coral-reefs in almost all the islands, render this last supposition very probable.
On the Oriental side the difficulty is greater; for here we find, what seem to be clear indications of a connection with Africa, as well as with Continental Asia, at some immensely remote epoch. Cynopithecus, Babirusa, and Anoa; Ceycopsis, Streptocitta, and Gazzola (s. g.), and perhaps Scissirostrum, may be well explained as descendants of ancestral types in their respective groups, which also gave rise to the special forms of Africa on the one hand, and of Asia on the other. For this immigration we must suppose, that at a period before the formation of the present Indo-Malay Islands, a great tract of land extended in a north-westerly direction, till it met the old Asiatic continent. This may have been before the Himalayas had risen to any great height, and when a large part of what are now the cold plateaus of Central Asia may have teemed with life, some forms of which are preserved in Africa, some in Malaya, and a few in Celebes. Here may have lived the common ancestor of Sus, Babirusa, and Phacochœrus; as well as of Cynopithecus, Cynocephalus, and Macacus; of Anoa and Bubalus; of Scissirostrum and Euryceros; of Ceyx, Ceycopsis, and Ispidina. Such an origin accounts, too, for the presence of the North-Indian forms in Celebes; and it offers less difficulties than a direct connection with continental Africa, which once appeared to be the only solution of the problem. If this south-eastward extension of Asia occurred at the same time as the north-eastward extension of South Africa and Madagascar, the two early continents may have approached each other sufficiently to have allowed of some interchange of forms: Tarsius may be the descendant of some Lemurine animal that then entered the Malayan area, while the progenitors of Cryptoprocta may then have passed from Asia to Madagascar.
It is true that we here reach the extremest limits of speculation; but when we have before us such singular phenomena as are presented by the fauna of the island of Celebes, we can hardly help endeavouring to picture to our imaginations by what past changes of land and sea (in themselves not improbable) the actual condition of things may have been brought about.
II. Australia and Tasmania, or the Australian Sub-region.
A general sketch of Australian zoology having been given in the earlier part of this chapter, it will not be necessary to occupy much time on this sub-region, which is as remarkably homogeneous as the one we have just left is heterogeneous. Although much of the northern part of Australia is within the tropics, while Victoria and Tasmania are situated from 36° to 43° south latitude, there is no striking change in the character of the fauna throughout the continent; a number of important genera extending over the whole country, and giving a very uniform character to its zoology. The eastern parts, including the colonies of New South Wales and Queensland, are undoubtedly the richest, several peculiar types being found only here. The southern portion is somewhat poorer, and has very few peculiar forms; and Tasmania being isolated is poorer still, yet its zoology has much resemblance to that of Victoria, from which country it has evidently not been very long separated. The north, as far as yet known, is characterised by hardly any peculiar forms, but by the occurrence of a number of Papuan types, which have evidently been derived from New Guinea.
Plate XI.
