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Show 454 ISLAND LIFE. (PART 11. the birds. The lizards belong to three genera,-~inulia and M ocoa, wh 1. 0h h ave a w1' de ranOo" e in the Easte. rn tropws and. the Pacific and Malayan regions, as well as Austra~a ; and N ault~nus, a genus peculiar to New Zealand, but belongmg to a familyGeckotidre; spread over the whole of the warmer parts of tho world Australia on the other hand, has three small but peculiar families, ~nd no less than thirty~six peculiar gene~a of lizards, many of which are confined to 1ts temperate regwns, but no one of them extends to temperate New Zealand. Tho extraordinary lizard-like Hatteria punct~ta ~f New Zealand forms of itself a distinct order of rept1les, m some respects intermediate between lizards and crocodiles, and having therefore no affinity with any living animal. The only representative of the Amphibia in New Zealand is a solitary frog of a peculiar genus (Liopelma hochstetteri); but it has no affinity for any of the Australian frogs, which arc numerous, and belong to eleven different families; while tho Liopelma belongs to a very distinct family (Bombinatoridm), confined to Europe and temperate South America. Of the fresh-water fishes we need only say here, that none belong to peculiar Australian types, but are related to those of temperate South America or of Asia. The Invertebrate classes are comparatively little known, and their modes of dispersal are so varied and exceptional that the facts presented by their distribution can add little weight to those already adduced. We will, therefore, now proceed to the conclusions which can fairly be drawn from the general facts of New Zealand natural history already known to us. IJed~wtions from the peculiarities of the New Zealand Fa'l~na.The total absence (or extreme scarcity) 'Of mammals in New Zealand obliges us to place its union with North Australia and New Guinea at a very remote epoch. We must either go back to a time when Australia itself had not yet received the ancestral forms of its present marsupials and monotremes, or we must suppose that the portion of Australia with which New Zealand was connected was then itself isolated from the mainland, and was thus without a mammalian population. We shall see in our next chapter that there are certain facts in the distribution CH.A.P. XXI.] NEW ZEALAND. 455 of plants, no less than in the geological structure of the country, which favour the latter view. But we must on any supposition place the union very far back~ to account for the total want of identity between the wingeu birds of New Zealand and those peculiar to Australia, and . a similar want of accordance in the lizards, the fresh-water fishes, and the more important insectgroups of the two countries. From what we know of the long geological duration of the generic types of these groups we must certainly go back to the earlier portion of tho Tertiary period at least, in order that there should be such a complete disseverance as exists between tho characteristic animals of the two countries; and we must further suppose that, since their separation, there has been no subsequent union or sufficiently near approach to allow of any important intermigration, even of winged birds, between them. It seems probable, therefore, that tho Bampton shoal west of New Caledonia, and Lord Howe's Island further south, formed the western limits of that extensive land in which the great wingless birds and other isolated members of the New Zealand fauna were developed. Whether this early land extended eastward to the Chatham I slands and southward to the .Macquaries we have no means of ascertaining, but as the intervening sea appears to be not more than about 1,500 fathoms deep it is quite possible that such an amount of subsidence may have occurred. It is possible, too, that there may have been an extension northward to the Kermadec Islands, and oven further to the Tonga and Fiji Islands, though this is hardly probable, or we should find more community between their productions and those of New Zealand. A southern extension towards the Antarctic continent at a somewhat later period seems more probable, as affording an .easy passage for the numerous species of South American and Antarctic plants, and also for the identical and closely allied fresh-water fishes of these countries. The subsequent breaking up of this extensive land into a number of separate islands in 'vhich the distinct species of moa and kiwi were developed-their union at a later period, and the final submergence of all but the existing islands, is a pure |