habitats, and of such occasional visitants as Hirundo nigricans, Eurystomus pacificus, Platelia regia, and others, but certainly appears to be a heavy task for Nyclicorax caledoniensis and Zosterops lateralis. Mr. Wallace himself, however, calls attention (in the work above referred to) to the fact, that small and weak birds are often carried accidentally across great widths of ocean by violent gales, and instances the case of the large number of North American birds which are from time to time found on the coasts of Europe during the prevalence of westerly winds. The occurrence in New Zealand, of forms common to it and Australia is, therefore, explicable without resorting to any supposition of a former land connection; and the discovery in New Zealand, within the few years which have elapsed since the colonization of the islands, of no less than eight instances of occasional visitants from Australia and Tasmania, gives strength to the supposition that they were aided in their transit by strong north-westerly winds. In this connection I may mention that the common sparrow has recently found its way to the Chatham Islands without man's intervention, no doubt assisted across the intervening waters by a north-west gale, and although both Mr. Wallace and Dr. Buller treat Zosterops lateralis as a true New Zealand form, I think it pretty certain that we owe its presence here and in the Chathams to a similar cause. The enormous increase in the numbers of this bird which has taken place both in Australia and New Zealand, is evidently due to a corresponding increase in the quantity of suitable food provided by the introduction, into both countries, of various kinds of succulent fruits, and of a great variety of foreign insects. The Maoris, who now capture the Zosterops in thousands for potting-down, and who are very shrewd and intelligent observers, unhesitatingly assert that it is a stranger and of comparatively recent appearance in these islands.

Mr. Wallace is in error, moreover, in supposing that the Zosterops found in the Chathams differs from the form which occurs in the main islands.

Reverting now to the principal objects of these notes, I find from the Hand-book that the seven orders which I am dealing with comprise (exclusive of occasional visitants from Australia) 19 families, 47 genera, and 88 species, the occasional visitants from Australia and Tasmania numbering 8 species belonging to 6 families and 7 genera.

Of the 47 genera, 25 have only one species each, 10 have two species, 7 have three species, 3 have four species, and 2 have five species.

Of the 88 species (excluding, as above-mentioned, the occasional visitants) 66 are peculiar to the main islands the Chathams and the Auck-lands together, 18 are common and peculiar to both the main islands, 8 are common and peculiar to the main islands and the Chathams, 3 are common and peculiar to the main islands and the Aucklands, 22 are common

to the main islands and habitats outside of them and of the Chatham and Auckland Islands, 9 are peculiar to the North Island, 16 to the South Island, 6 to the Chathams, 2 to the Aucklands, 1 is common and peculiar to the North Island and the Chathams, 2 are common and peculiar to the South Island and the Chathams, and 1 is common and peculiar to the main islands and the Chatham and Auckland Islands. In making this analysis I have assumed that Dr. Buller has seen good reasons for reaffirming Platycercus alpinus as a species, notwithstanding the remarks on the subject in his larger work, and that there is also good ground for including the bird called called Platycercus rowleyi as a species; it seems, too, that Dr. Buller does not accept Finsch's views in relation to Apteryx australis and Apteryx mantelli. Assuming these points, and looking, in the first place, at the species peculiar and common to both the main islands only on the one hand, and those peculiar to the North Island on the other, it will be seen that there is only one instance in which any genus represented amongst the latter is represented by species amongst the former, namely, in the case of Apteryx, there being only one species, out of the four belonging to that family, which is common to both islands, namely Apteryx oweni, unless we accept Dr. Finsch's views that Apteryx mantelli is only a variety of Apteryx australis; and then, looking at those species which are peculiar and common to both the main islands only on the one hand, and those peculiar to the South Island on the other, it will be seen that there are four instances in which a genus represented amongst the latter is represented by species amongst the former, namely, in the cases of Zenicus, Sphenœacus, Nestor, and Apteryx.

Of the species peculiar to the North Island there are seven, namely Orthonyx albicilla, Petroica toitoi, Petroica longipes, Turnagra hectori, Glaucopis wilsoni, Apteryx mantelli and Ocydromus earli, which have representative species in the South Island, namely, Orthonyx ochrocephala, Petroica albifrons, Turnagra crassirostris, Glaucopis cinerea, Apteryx australis, Apteryx haastii, and Ocydromus australis, fuscus and brachypterus, whilst the remaining two of those which are peculiar to the North Island, namely Pogonornis cincta, and Heteralocha acutirostris, although each belongs to a family of which there are genera in each island, have no special representatives in the South Island. In like manner two of the species peculiar to the South Island, namely Certhiparus novæ-zealandiæ and Notornis mantelli, although each belongs to a family of which there are genera in both islands, have no special representatives in the North Island, whilst the genus Notornis is represented by Notornis alba in Norfolk Island, one of the most distant of the outlying districts assigned to the New Zealand zoological sub-region.

I have already mentioned that the North Island possesses nine species peculiar to itself, of which Orthonyx albicilla is represented in the South Island by Orthonyx ochrocephala. The latter is a very different-looking and somewhat more robust bird than its North Island congener, but not-withstanding this difference in size and the greater differences which the two forms present in external characters, they both have precisely the same habits and notes. The differences between the external characters of the species of Petroica, Turdidæ, Apterygidæ, and Ocydromus peculiar to each of the main islands, though less manifest than in the case of the two species of Orthonyx, is very well marked, but in each of these instances also the habits and notes of the birds are the same. In the case of the Corviæ, the North Island species is only distinguished from the South Island one by its slightly larger size and by the colour of the wattles, but in this instance also the notes and habits of the birds are identical. It will have been observed by those who have seen them in their natural state, that, with the possible exception of Pogonornis cincta, all the birds of flight peculiar to the North Island, and with the exception of the two species of Nestor, all those peculiar to the South Island, which frequent forest habitats in the respective islands, are birds which never voluntarily rise above the level or move outside the limits of the forests in which they dwell, and the chances are, therefore, very remote that any of them should pass, in numbers at all events, across the waters dividing the two islands.

The same observations may be applied to a large proportion of the species common and peculiar to the two islands, rendering it remarkakle that so many of them should have retained common characters during the enormous period that must have elapsed since the formation of Cook Straits.

The non-occurrence of Heteralocha acutirostris in the South Island may excite surprise; but it must be remembered, in the first place, that this is one of the birds which never voluntarily rises above the level or passes outside of the limits of the forest in which it lives, and in the next, that its range, even in the North Island, is restricted to mountain districts so placed that the only winds of sufficient strength to overcome the efforts of stray birds to return to their own special abode, would prevent their crossing the dividing waters. The restriction in the range of this bird is, however, not so surprising as that which occurs in the cases of Nestor occidentalis and Nestor notabilis in the South Island, seeing that, apparently, the very same natural conditions as those which characterize their respective special habitats, extend over a large portion of both islands. We are but little aware of the circumstances which operate in causing a restriction in the range of any particular species, or which may lead to the local

extinction of some particular form, and until we have before us well-considered observations on both these subjects, we must remain unable to account for such cases as those last above referred to.

A very remarkable instance of rapid and apparently unaccountable extinction is presented to us in the North Island, in the case of Anthornis melanura. For years after this colony had been settled this bird was common all over both islands; but it seems to have disappeared from the North Island, although at present it is not merely abundant but actually increasing in numbers on the other side of the Straits. The rat and the bee may each have played a part in bringing about its disappearance from the North Island, as both of these swarm all through the forest there, whilst in the South Island the rat has been nearly extirpated from the great Fagus forests by the woodhen (Ocydromus), and the bee is limited in its range to the cultivated districts. But the cause of the disappearance of this bird is mere matter of speculation, and I have only cited the case in order to show how little we really know of the circumstances which may govern or limit the distribution of any particular species.

I do not know upon what authority Dr. Buller (in his Manual) has given the Chatham Islands as a habitat of Stringops habroptilus. I find no mention of this in his larger work. He probably follows Mr. Wallace in making the statement, but without giving the reasons assigned for it by that writer. Mr. Wallace says (speaking of the Chatham Islands) “that the Natives—I presume the Morioris—declare that both the Stringops and Apteryx once inhabited the islands, but were exterminated about the year 1835.” In the first place, so far as I have been able to ascertain, the Morioris had no knowledge whatever of either Stringops or Apteryx. In the next place, the date fixed for their extirpation is singular. It was in that year that a numerous war-party of the Ngatitama (one of the most savage and ruthless of the New Zealand tribes) chartered a whaleship to take them to the Chathams, the existence of that group and its occupation by a peaceful and well-fed people having been reported to them by a member of their tribe, who was serving as a sailor in an European vessel which had then recently come into Wellington Harbour after visiting that group.

The Ngatitama invaded the islands for the sole purpose of slaughter and cannibalism, and, in the course of a very few months, had nearly “extirpated” the unfortunate Morioris, one of the leading chiefs of the invaders (whose taiaha, made from the bone of a whale, is in the Wellington Museum) actually living for many months almost exclusively upon the flesh of young children. Until the statement above referred to had appeared in Mr. Wallace's work, my son, who was the first to collect systematically the fauna and flora of the Chatham Islands, and who spent upwards of a year

there for that purpose, and who was diligent in his enquiries, had never heard it even suggested that either Slringops or Apteryx had existed there. He was informed that a bird described as resembling a New Zealand Ocydromus was formerly found abundantly on the main island of the group, but he believes that the bird referred to was Rallus dieffenbachii, of which Dr. Buller tells us that the last recorded specimen was obtained by Dr. Dieffenbach in 1842. At all events I am not disposed to accept statements as to the occurrence either of Stringops or Apteryx in this habitat until something more satisfactory than the alleged “declaration of the Natives” is brought forward in support of it.

It has been suggested that specimens of Stringops and of some South Island species of Apteryx may have been taken to the Chathams by Maori voyagers, which I do not however believe, and therefore, whilst the occurrence of a form of Ocydromus upon this group would not have been very surprising, that of Stringops and Apteryx would, if for no other reasons than, firstly, that no part of the islands presents physical conditions at all similar to those which obtain in the known habitats of those birds; and, secondly, that had these birds ever existed there at all, they would certainly have been extirpated by the Morioris long before the latter were themselves practically extirpated by the Ngatitama. Assuming, however, that the Chatham Island habitat may be eliminated from the question, the continued existence in both the main islands of New Zealand of such forms as Stringops habroptilus and Apteryx oweni is a most noteworthy and extraordinary fact. It will be observed that all the other birds mentioned in the tables, as well those common and peculiar to both the main islands as those common to them and to other habitats, possess powers of flight which prevent any suggestion of impossibility in accounting for their distribution, and that in the cases in which particular species in one of the main islands are represented by species in the other, the ordinary laws of variation may be sufficient to account for the observed differences. But the persistency of such types as Stringops and Apteryx oweni stands upon a different basis, unless we resort to the suggestion that each of these species may have been introduced by Maori voyagers from the South to the North Island within comparatively recent times, it being noteworthy that both are used as call-birds and pets by the native inhabitants of the South Island districts in which they are found.

Setting aside the supposed occurrence of Stringops, Apteryx, and Ocydromus in the Chathams, we have certain facts in connection with the species peculiar to that group, which add considerable strength to the conclusion derived from an examination of its flora, namely, that it was formerly directly connected by land with the main islands of New Zealand. In the