xiv DISTRIBUTION 605 



wards from South America, and including many of the Pacific 

 Islands ; and an area, also of less than 2,000 fathoms, 

 in the Antarctic Ocean, sending offshoots northwards. The first 

 of these may possibly indicate a former westward extension of 

 South America, the second a former Antarctic land-area, perhaps 

 more or less directly connected with the existing southern conti- 

 nents. The whole question is quite unsettled and extremely 

 obscure, and is complicated by the fact that in one respect the 

 New Zealand fauna shows Ethiopian affinities. There have been 

 discovered in the Chatham Islands, a small group about 400 

 miles to the east of New Zealand, the remains of a long-beaked 

 Rail (Diaphorapteryx), evidently not long extinct, the nearest ally 

 of which is the Red Bird (Aphanapteryx) of Mauritius, known to 

 have been exterminated by human agency. Moreover, the great 

 Ratite Birds, the ^Epyornithidae, of Madagascar show undoubted 

 affinities with the Dinornithida3. 



The foregoing comparison of the faunae of Great Britain and 

 New Zealand leads us to the consideration of certain fundamental 

 conceptions of zoo-geography. 



Insular Faunae. We notice, in the first place, the striking 

 contrast between the fauna of an island which has been recently 

 detached from a great continental area and that of an island 

 which has remained isolated for an immense and unknown period. 

 In the one case the fauna has a strictly continental character, 

 there having been insufficient time for modification since the 

 separation took place. In the other case immigration has taken 

 place from various sources over a vast period of time, during which 

 modification has taken place to a sufficient extent to give rise to 

 new or endemic species. 



Habitat, Range, and Station. Each kind of animal has, as 

 a rule, its own habitat, fresh-water in one case, the sea between 

 tide-marks in another, marsh, forest, snow-clad peaks, and so on. 

 A similar habitat may characterise whole genera and even orders. 

 Keeping always to its own habitat, the range of an animal may 

 extend over a vast area. The marsh-loving Curlew, for instance, 

 is found all over the world ; the Cormorants (Phalacrocorax), Gulls 

 (Larus), some Ducks (Anas), &c., are also cosmopolitan or world- 

 wide in distribution. On the other hand, the range of a species, 

 genus, or order may be restricted to a single limited district. The 

 genus Liopelma (New Zealand Frog) is found only in certain 

 very limited areas ; the species Salmo killinensis (Loch 

 Killin Char) occurs only in Loch Killin in Inverness-shire ; the 

 Order Rhynchocephalia is confined to New Zealand. The entire 

 range may be broken up, as it were, into a number of stations, 

 depending sometimes on habitat, sometimes on unknown causes ; 

 the Tuatara, for instance, is found at present only in some half- 



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