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Insular or "Malayan" Province.-The northern boundary of the Insular Province is not at present easily determinable, but it is quite evident that, as already stated, the southern maritime portions of Indo-China belong here rather than with the northern division of the Indian Region. To the southward and eastward it embraces, as already explained, the Sunda Islands, the Philippines, and Celebes. Of the eighty-three genera occurring in it, twenty-five, or nearly one fourth, are peculiar, while twenty-seven others do not range beyond the Indian Province. Twenty of the remainder are properly Indo-African genera, while about a dozen others have a wide extralimital range, and about the same number have a very local range, the larger islands having each one or two peculiar genera. Aside from several tropicopolitan genera of Bats, and the wide-ranging genera Sus and Mus, only one genus is properly Australian, and this is a straggler that merely reaches Timor and Celebes. As would be expected, the larger central islands, together with Malacca and the mainland belt, possess the richest and most varied fauna, the smaller outlying islands presenting a paucity of types proportionate to their size and isolation.

Timor, considering its close proximity to Australia, is remarkably free from Australian forms, presenting, in common with Celebes, the single Marsupial genus Cuscus. The distribution of the genera of this province is roughly indicated in the subjoined table. Notwithstanding its much smaller land-area, and the fact that it has ten less genera than the Continental Province, it has, as would be naturally expected, many more peculiar genera,* the ratio of peculiar genera in the one being as 16 to 94, and in the other as 25 to 83.

* Four, however, are peculiar only in regard to the Indian Region, they being simply wide-ranging tropical forms that are unrepresented in the Continental Province.

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Restricted to the province*.

Restricted to the Indian Region.....

Found outside of the Indian Region in the African only.

Common to the African and Indian Regions

Wide-ranging (exclusive of tropicopolitan).

Of local distribution

Restricted to Borneo

Restricted to Borneo and Sumatra..

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* Exclusive of several tropicopolitan genera not occurring elsewhere in the Indian Region.

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The Australian Realm will be here restricted so as to embrace none of the islands situated to the westward of the Moluccas. The Molucca Group forms a transitional link between the Indo-African and the Australian Realm, but they are faunally more closely allied to the latter than to the former. These islands embrace, excluding Chiroptera and species probably or known to have been introduced by man,* only a single genus (Sorex) of Placental Mammals, while two genera of Papuan Marsupials (Cuscus and Belideus) are abundantly represented.

The Australian Realm, considered as a whole, is made up of very heterogeneous elements, its land-surface consisting of islands, many of them of small size and widely scattered. The mammals are almost wholly limited to its three larger constituents,-Australia, Tasmania, and New Guinea, and a few of the larger islands in close proximity to them. Among the prominent types very generally represented throughout all of these areas are several wide-ranging (almost tropicopolitan) genera of Bats, which, in consequence of their wide geographical range, wholly fail to be distinctive, and may hence be safely ignored in the following general analysis of the region. The marine species (the Dugong and various species of Seals) are likewise of small importance in the present connection, since they are all wide-ranging species, not properly charac teristic of the region. After these eliminations, we have left a few genera of Murida and the distinctively characteristic implacental mammalia. The latter, with the exception of a single family (Didelphida, occurring now only in the warmer parts of the two Americas), are found nowhere else, and hence give to the region an exceptional distinctness as a primary zoogeographical region. The numerous groups of small, widely scattered islands, usually considered as collectively forming the Polynesian Region, being destitute of mammalia, need not be here further considered.

New Zealand, situated more than a thousand miles to the southeastward of Australia (its nearest large land-area), is also wholly deficient in characteristic forms of mammalia; the only representatives of this class, aside from Seals and Bats, being a Rodent, supposed, rather than certainly known, to be found there. The Seals are wide-ranging species, and of the two species of Bats, one has Australian and the other South

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These include, besides the common domestic species, Cynopithecus nigrescens, Viverra tangalunga, Babirusa alfurus, and Cervus hippelaphus var. moluccensis, considered by Mr. Wallace as "probably" or "almost certainly" introduced by man, since they are species "habitually domesticated and kept in confinement by the Malays".-Geogr. Dist. Anim., vol. i, p. 417.

American affinities. Judged by other classes of animals, the fauna of New Zealand is Australian (or Australian and Polynesian), but is yet so specialized that the New Zealand islands must be recognized as forming a distinct and highly differentiated region (New Zealand Region) of the Australian Realm.

As regards mammalia (and the same is true of the fauna and flora considered collectively), Tasmania, Australia, and New Guinea have many features in common, fully one-half of the genera (seven out of fourteen) of mammals occurring in Tasmania being represented not only throughout the greater part of Australia, but also in New Guinea.

Tasmania and New Guinea are less rich in mammalia than Australia, but this is obviously due to their insular character and small area. Tas mania is scarcely more closely related to Southern Australia than New Guinea is to Northern Australia. Formerly, New Guinea was thought to be very distinct from Australia, but the recent exploration of the interior of New Guinea by MM. Beccari, d'Albertis, and Laglaize, has brought to light the existence there of many forms before supposed to be restricted to Australia and Tasmania. M. Alphonse Milne-Edwards, in a recent communication to the French Academy respecting some new species of mammalia discovered in New Guinea by M. Laglaize, in referring to the close relationship existing between the fauna of New Guinea and Australia, thus observes:-" Plus on étudie la faune de la NouvelleGuinée, plus on lui trouve de ressemblance avec celle de l'Australie, et les indications fournies par la répartition des espèces animales permet d'affirmer qu'autrefois ces terres ne formaient qu'un seul grand continent. Déjà les résultats des voyages de circumnavigation entrepris dans la première moitié de ce siècle . . avaient permis de soupçonner cette conformité d'origine; mais elle a été principalement mise en lumière à la suite des explorations de M. Wallace, de M. Beccari et de M. d'Albertis. Enfin les collections qui M. Laglaize a formées dans ces régions, ainsi que celles qui lui ont été remises par M. Bruijn et qui viennent d'arriver en France, fournissent des faits nouveaux qui accentuent encore les ressemblances entrevues."*

Formerly the Monotremes were supposed to be restricted to the southern half of Australia and Tasmania, but within the last two or three years the existence of Tachyglossus in North Australia (latitude 21°) has been established, and an allied species has been discovered in the mountains of New Guinea. M. A. Milne Edwards has also just described a species of Dromicia from New Guinea, and also a species of Hapalotis, and Dr. Peters has recently added species of Phalangista, Chatocercus, and Hydromys, making six genera recently discovered in New Guinea that were previously known only from Australia and Tasmania.

So far as at present known, only three or four genera (Uromys, Dendrolagus, Dorcopis, and Myæctis) of mammals are peculiar to New Guinea and the small islands situated between New Guinea and Australia, and Compte-rendu, tom. lxxxv, 1079, déc. 3, 1877.

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probably some of these will yet be found in Australia. One of these (Myoctis) has been thus far reported only from the Aru Islands. As Tasmania has two peculiar genera (Thylacinus and Sarcophilus), New Guinea, in view of its four or five times greater area, is in reality scarcely more specialized than is Tasmania, and is hence faunally as much a part of Australia as is the latter. As will be shown later, nearly as many of the genera occurring in Southern Australia have been found in New Guinea as in Tasmania. Scarcely two years ago Mr. Wallace stated that "as yet no other [referring to the genus Sus] nonmarsupial terrestrial mammal has been discovered [in "Papua, or the New Guinea Group"] except a Rat, described by Dr. Gray as Uromys aruensis, but about the locality of which there seems some doubt."* This genus has not only now been established as occurring there, but four additional species of it have been described by Dr. Peters, who has also added a species of Hydromys, and Mr. Alston has added a species of Mus and M. A. Milne-Edwards a species of Hapalotis, in all seven species, belonging either to Australian genera or having decided Australian affinities.

Regions of the Australian Realm.-Accepting the Polynesian Islands as forming one region (the Polynesian), and New Zealand as constituting another (the New Zealand), we have left for detailed considera. tion only the larger land-masses, consisting of Tasmania, Australia, and New Guinea with its associated islands, forming the third or Australian. The close zoological affinity of Tasmania and Australia no one questions, and it has been already shown that New Guinea and Australia are almost equally inseparable. Although many genera range from Tasmania across Australia into New Guinea, this large area, embra cing as it does nearly fifty degrees of latitude, falls naturally into two well-marked subdivisions, the one tropical the other temperate. These

* Geogr. Distr. Anim., vol. i, pp. 409, 410.

In 1871, in referring to the Australian Realm (Bull. Mus. Comp. Zoöl., vol. ii, p. 381), I said:-" It is divisible into a Temperate and a Tropical Region, the former embracing New Zealand and Australia." The latter portion of this statement was of course made without due consideration. As already stated, New Zealand has no intimate relationship with Australia, and should be treated as a separate and independent region of the Australian Realm. Mr. Wallace, in stating his "* Objections to the System of Circumpolar Zones" (Geogr. Distr. Anim., vol. i, p. 67), has very naturally taken notice of this unfortunate slip, and cites it as evidence of the "erroneous results" that follow from the adoption of the principle of the "distribution of life in circumpolar zones". My "separation of New Zealand to unite it with the southern third of Australia was certainly most thoroughly erroneous; but while, as Mr. Wallace says, the fauna of Australia, taken as a whole, is exceptionally homogeneous, I cannot agree with him that New Guinea, so far at least as its mammalian fauna is concerned, is as sharply differentiated from Australia as any adjacent parts of the same primary zoological region can possibly be "-in other words, that it can be only arbitrarily joined with the northern portion of Australia. I freely admit that I was not only in error as regards New Zealand, but also in respect to my division of the Australian continent, and I accept this portion of Mr. Wallace's criticism as fairly made. That the error was not one of "principle", but merely a wrong application of a principle, I think the text

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