184 Transactions. — Zooloyy. 



first place, five of the six peculiar species have representatives in both the 

 main islands of New Zealand, but are themselves specifically distinct from 

 any of the latter, the Anthorms and Ralliis especially presenting marked 

 differences from the New Zealand forms. Except in these more extreme 

 instances, the variations in the other species are very similar in extent to 

 those which are presented by their respective special representatives in the 

 main islands. 



It will be observed too that, except in the case of Anthomis, all the 

 above instances are those of birds of weak flight and of close habits. The 

 case of Cabalus modestus is one of peculiar preservation, analogous to that of 

 Notomis in the South Island. 



The Auckland Island birds call for less remark, the only species peculiar 

 to that group which has any general representative in New Zealand being 

 Rallies brachipus, whilst the four species common to both habitats are all 

 birds of strong flight. 



Of the birds common to the New Zealand zoological sub-region and 

 habitats outside of it, the only instances which present any peculiarity are 

 Ortygometra tabuensis and Porphyria melanotics. The former is a peculiarly 

 close bird in its habits, and seldom takes wing when pursued, but its powers 

 of flight are considerable when put in use. The latter is a heavy and 

 laboured flier, and although we may not marvel at its presence in both 

 the main islands and even in the Chathams, it is not easy to account for 

 the persistency of a species so widely distributed and so unlikely to under- 

 take a migration from one zoological district to another, more especially if 

 the distance between them be great. 



I do not pretend to account for the differences observable between 

 the species common and peculiar to the main islands and the allied 

 species peculiar to each, or, indeed, for any other of the phenomena 

 above referred to ; the full materials for such a purpose having yet to 

 be collected. 



It will be seen that many of the instances to which I have called atten- 

 tion bear a strong analogy to the cases observed by the late Mr. Charles 

 Darwin in the Gallipagos Islands, and that we have in relation both to that 

 and to our own group, a problem of no ordinary difficulty to solve. Its 

 solution may not be beyond our reach, but can certainly only be arrived at 

 by patient and exhaustive observations. 



The tables appended to these notes will probably be found to be useful 

 addenda to the recently published manual. 



