184 Transactions.— Zoology. 
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 Anthornis and Rallus 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 Anthornis, 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 
Notornis 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 
Rallus 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 Porphyrio melanotus. 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. 
