Type, a caste of the distal portion of the right tibio-tarsus, in the British Museum. The original is preserved in the Museum at Sydney and was obtained from the pleistocene cavern-deposits in the Wellington Valley in New South Wales.
A bird usually stated to be extinct is Monarcha dimidiata, from Rara-Tonga, but in March, 1901, two specimens, male and female, were procured by the Earl of Ranfurly. Doubtless this is a species which will one day vanish entirely, but at present it hardly comes within the scope of this work.
The birds known to be more or less on the verge of extinction which I have not thought advisable to give in the main part of this book might, for convenience of reference and to avoid possible controversy as to my having omitted any species, be given here, but it must be understood that of these species I only know the fact that their numbers have been greatly reduced and mostly almost to vanishing point. I have already mentioned before that some of them may already have disappeared, but in many cases recent investigations are wanting, and all, therefore, that can be said of them is that they are threatened and may soon become extinct, if they still exist.
Many of my readers will, I fear, find fault with me for having bestowed names on a number of forms, known only from fragments of bones, single bones, or two or three bones. Especially will they, I fear, blame me for doing this when these forms have been described by other authors who have refrained from giving names. My reasons for doing so are very simple: in such cases as Dr. Parker's species which are fully described, but quoted under the formula Pachyornis species A or Anomalopteryx species B, the danger lies in different authors using the same formula for quite other species. In the case of others, where an author fears to name a form, but gives the distinctive characters and quotes only Casuarius species or Emeus sp., unless the author and page are quoted, confusion must arise, and so in both cases I have thought it easier for reference and also more concise to name all these forms which have been described or differentiated without a binomial or trinomial appellation. I have, however, refrained from doing so in the foregoing list of Pleistocene species in the
following eight cases as I was not able to decide anything about them with the material or literature at my disposal, viz.:—
| Phalacrocorax sp. Lydekker | New Zealand. |
| Anser sp. Lydekker | England. |
| Cygnus sp. Lydekker | Malta. |
| Gallus sp. Lydekker | New Zealand. |
| Gallus sp. Lydekker | Central Germany. |
| Phasianus sp. Lydekker | Germany. |
| Perdix sp. Issel | Italy. |
| Tetrao sp. Issel | Italy. |