Buller. — Illustrations of Darwinism. 99 



landicus), much smaller, but in other respects similar to our 

 Platycercus nova-zealandia. Eepresenting our Ballus philip- 

 pensis, there is a very distinct species of Rail (Ballus muelleri, 

 Rothschild), of which the only known specimen is in the 

 Natural History Museum at Stuttgart ; and, as if representing 

 our Anas chlorotis, there is a flightless Duck (Nesonetta auch- 

 landica) frequenting the seashore as well as the streams. But, 

 what is still more significant and curious, there exists in the 

 Auckland Islands a species of Merganser (Mergus australis), of 

 which there is no representative in New Zealand, or indeed 

 anywhere else in the Southern Hemisphere. The Bell-bird is 

 there also, but it seems to be absolutely identical with the New 

 Zealand form (Anthornis melanura), showing, as I think, a 

 comparatively recent introduction. 



On x\ntipodes Island, as already indicated, there is a 

 strictly endemic Parrakeet (Platycercus unicolor), a species 

 living abundantly on this oceanic rock, but not to be met with 

 in any other part of the world, and commingling with a species 

 (Platycercus erythrotis) more nearly approaching to the typical 

 • Platycercus nova-zealandia. Going further south we come to 

 Macquarie Island, where there is a Rail differing so perceptibly 

 from ordinary examples of Ballus philippensis that Professor 

 Hutton has proposed to distinguish it as Ballus macquariensis ; 

 and, although I am not prepared to concede to it distinct rank 

 as a species, its presence there is another proof of the existence 

 of transitional forms. It is an inexplicable fact, however, that 

 ■on the same island is to be found the flightless Ocydromus earli, 

 differing in no respect from examples obtained in New Zealand 

 and on Stewart Island.* 



On the Snares, a group of islets about seventy miles south 

 ■of the southernmost extremity of New Zealand, there is a 

 peculiar form of Fern-bird, which I have recently distinguished 

 under the name of Sphcnazacus caudatus, very similar to 

 Splienceacus punctatus of New Zealand, but quite distinct as a 

 species, and being intermediate in character between the last- 

 named bird and Spilienceacus rufescens of the Chatham Islands. 

 Now, no ornithologist who has studied the subject can doubt 

 that these three closely-allied forms, although now perfectly 

 distinct as species, have sprung from a common parent-form. 

 Curiously enough, another Chatham Island bird, the Black 

 Robin (Miro traversi) is abundant on the Snares, although not 

 found in any part of New Zealand. 



* Since the above was written I have had from Captain Fairchild 

 what seems to be a sufficient explanation of this. He states that, about 

 the year 1830, Captain Gilroy (who is still living at the Bluff) was first 

 mate of a small sealing vessel visiting the Macquaries, and that, in order 

 to provide another source of food-supply, he brought a number of live 

 Woodhens from New Zealand and turned them loose there. 



