longing to a different family, the Casurariidae. To the right are a pair of crested pigeons (Ocyphaps lophotes), one of the many singular forms of the pigeon family to which the Australian region gives birth. In every other part of the globe pigeons are smooth-headed birds, but here they have developed three distinct forms of crest, as seen in this bird, the crowned pigeon figured in Plate X., and the double-crested pigeon (Lopholamus antarcticus). The large bird on the tree is one of the Australian frog-mouthed goat-suckers (Podargus strigoides), which are called in the colony "More-pork," from their peculiar cry. They do not capture their prey on the wing like true goat-suckers, but hunt about the branches of trees at dusk, for large insects, and also for unfledged birds. A large kangaroo (Macropus giganteus) is seen in the distance; and passing through the air, a flying opossum (Petaurus sciureus), a beautiful modification of a marsupial, so as to resemble in form and habits the flying squirrels of the northern hemisphere.

III. The Pacific Islands, or Polynesian Sub-region.

Although the area of this sub-region is so vast, and the number of islands it contains almost innumerable, there is a considerable amount of uniformity in its forms of animal life. From the Ladrone islands on the west, to the Marquesas on the east, a distance of more than 5,000 miles, the same characteristic genera of birds prevail; and this is the only class of animals on which we can depend, mammalia being quite absent, and reptiles very scarce. The Sandwich Islands, however, form an exception to this uniformity; and, as far as we yet know, they are so peculiar that they ought, perhaps, to form a separate sub-region. They are, however, geographically a part of Polynesia; and a more careful investigation of their natural history may show more points of agreement with the other islands. It is therefore a matter of convenience, at present, to keep them in the Polynesian sub-region, which may be divided into Polynesia proper and the Sandwich Islands.

Polynesia proper consists of a number of groups of islands of some importance, and a host of smaller intermediate islets.

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For the purpose of zoological comparison, we may class them in four main divisions. 1. The Ladrone and Caroline Islands ; 2. New Caledonia and the New Hebrides; 3. The Fiji, Tonga, and Samoa Islands; 4. The Society, and Marquesas Islands. The typical Polynesian fauna is most developed in the third division; and it will be well to describe this first, and then show how the other islands diverge from it, and approximate other sub-regions.

Fiji, Tonga, and Samoa Islands. The land-birds inhabiting these islands belong to 41 genera, of which 17 are characteristic of the Australian region, and 9 more peculiarly Polynesian. The characteristic Australian genera are the following: Petroica (Sylviidæ); Lalage (Campephagidæ); Monarcha, Myiagra, Rhipidura (Muscicapidae); Pachycephala (Pachycephalidæ); Rectes (Laniida); Myzomela, Ptilotis, Anthochara (Meliphagidae); Amadina, Eythrura, (Ploceida); Artamus (Artamida); Lorius (Trichoglossidae); Ptilopus, Phloganas (Columbida); Megapodius (Megapodiida).

The peculiar Polynesian genera are:-Tature, Lamprolia (Sylviida); Aplonis, Sturnodes (Sturnida); Todiramphus (Alcedinidæ); Pyrhulopsis, Cyanoramphus, (Platycercidæ); Coriphilus (Trichoglossidæ); Didunculus (Didunculidæ).

The wide-spread genera are Turdus, Zosterops, Hirundo, Halcyon, Collocalia, Eudynamis Cuculus, Ianthenas, Carpophaga, Turtur, Haliaetus, Astur, Circus, Strix, Asio. The aquatic birds are fifteen in number, all wide-spread species except one-a form of moor-hen (Gallinulide), which has been constituted a new genus Pareudiastes.

Society, and Marquesas Islands.-Here, the number of genera of land-birds has considerably diminished, amounting only to 16 in all. The characteristic Australian genera are 5;-Monarcha, Anthochara, Trichoglossus, Ptilopus, and Phloganas. The Polynesian genera are 4;-Tatare, Todiramphus, Cyanoramphus, Coriphilus, and one recently described genus, Serresius, an extraordinary form of large fruit pigeon, here classed under Carpophaga. These remote groups have thus all the character of Oceanic islands, even as regards the rest of Polynesia, since they

possess hardly anything, but what they might have received by immigration over a wide extent of ocean.

Ladrone, and Caroline Islands.-These extensive groups of small islands are very imperfectly known, yet a considerable number of birds have been obtained. They possess two peculiar Polynesian genera, Tatare and Sturnodes; one peculiar sub-genus, Psammathia (here included under Acrocephalus); and ten of the typical Australian genera found in Polynesia,— Lalage, Monarcha, Myiagra, Rhipidura, Myzomela, Erythrura, Artamus, Phlogenas, Ptilopus, and Megapodius, as well as the Papuan genus Rectes, and the Malayan Calornis;—so that they can be certainly placed in the sub-region. Genera which do not occur in the other Polynesian islands are, Acrocephalus, (s.g. Psammathia) originally derived perhaps from the Philippines; and Caprimulgus, a peculiar species, allied to one from Japan.

New Caledonia, and the New Hebrides.-Although these islands seem best placed with Polynesia, yet they form a transition to Australia proper, and to the Papuan group. They possess 30 genera of land-birds, 18 of which are typical of the Australian region; but while 13 are also Polynesian, there are 5 which do not pass further east. These are Acanthiza, Eopsaltria, Gliciphila, Philemon, and Ianthanas. The peculiar Polynesian genus, Aplonis, of which three species inhabit New Caledonia, link it to the other portions of the sub-region. The following are the genera at present known from New Caledonia:-Turdus, Acanthiza, Campephaga, Lalage, Myiagra, Rhipidura, Pachycephala, Eopsaltria, Corvus, Physocorax (s.g. of Corvus, allied to the jackdaws), Glicphila, Anthochara, Philemon, Zosterops, Erythrura, Aplonis, Artamus, Cuculus, Halcyon, Collocalia, Cyanoramphus, Trichoglossus, Ptilopus, Carpophaga, Macropygia, Ianthœnas, Chalcophaps, Haliastur, Accipiter. The curious Rhinochetus jubatus, forming the type of a distinct family of birds (Rhinochetida), allied to the herons, is only known from New Caledonia.

It thus appears, that not more than about 50 genera and 150 species of land-birds, are known from the vast number of islands that are scattered over the Central Pacific, and it is not probable