Some other general schemes have been promulgated, as those of M. Trouessart and Professor Möbius; but they have found little support, and with regard to the Class _Aves_, though certainly not with regard to other groups as _Pisces_, or _Mollusca_, what is practically the scheme of Mr. Sclater has met with acceptance, whether with or without the modifications proposed by Huxley and Professor Newton, there being really but two important points of difference–(1) the recognition of New Zealand as a distinct Region, and (2) the union of the Nearctic and Palaearctic areas into a single Region. It would be impossible here to set forth the arguments by which these views are maintained or contested, and it must suffice to trace briefly the outlines of the several districts. _New Zealand_, if admitted as a distinct Region, consists only of the islands so named, the smaller Chatham, Auckland, and Macquarie groups, Antipodes Island, Lord Howe's, Norfolk and Kermadec Islands. The _Australian_, if the preceding be cut off, will include Tasmania, all Australia, and the islands to the northward as far as what has been called "Wallace's Line" (between Lombok and Bali), Celebes, New Guinea, New Britain, and all the countless groups of tropical islands in the Pacific Ocean–except the Galapagos, which undoubtedly belong to the next Region. The _Neotropical_ is made up of all South America, the Antilles and Central America, the only doubt being whether to draw the northern boundary so as to exclude or include Mexico, or even the southern part of the United States. To this naturally succeeds, but with an indefinite southern boundary, the _Nearctic_, comprising the whole of the rest of North America to the shores of the Polar Sea, with the addition of Greenland. Its north-western corner, Alaska, is now known to be largely tenanted by forms from Asia, not found elsewhere in America, and this is one of the chief reasons assigned for uniting it with the _Palaearctic_ area, which may be taken to include Japan and all continental Asia to the north of China proper, the Himalayas, the Persian Gulf and the east end of the Mediterranean. Some authorities would add Northern Arabia and Lower Egypt; but all have agreed to include Tunis and the ancient Mauritania–the Barbary States lying north of the Great Desert to the Atlantic Ocean about Mogador, as well as the Canaries, Madeira and the Azores, with the whole of Europe {17}from Greece to Iceland. What is left of Arabia and Africa, after taking off the above portions, with the addition of Madagascar and the Mascarene Islands, is the _Ethiopian_ Region; and all the rest of continental Asia, with the islands not included in the Australian Region, becomes the _Indian_, or, as it has lately been called, the _Oriental_. It would be quite impossible to enumerate here the various Sub-regions and Provinces into which these several Regions may be divided. The views of Mr. Wallace