Page:Transactions and proceedings of the New Zealand Institute (IA transactionsproc61873newz).pdf/182

118 Celebes, the Navigators, the Caroline Islands, New Caledonia, the Philippine Islands, and New Zealand, are referable to one and the same species, we are bound, it seems fo me, to acopt the older name of R. philippensis, Linn. (Syst. Nat., i, p. 263).

Hydrochelidon leucoptera, Temm.

I believe Capt. Hutton is right in his identification of Mr. Monro's specimen in the Colonial Museum, although Dr. Finsch thinks he has confounded it with H. hybrida, Pall. Almost immediately after my arrival in England I had an opportunity of examining a fine series of these birds in the collection of Mr. Howard Saunders, and having at that time a very distinct recollection of the New Zealand specimens, I satisfied myself that they were the same.

Eudyptes pachyrhynchus, Gray.

I have treated this in my work as a synonym of Eudyptes chrysocomus.

Apteryx mantelli, Bartl.

Dr. Finsch states that "after careful and repeated examination" of several specimens from both islands, he is unable to admit Apteryx mantelli (of the North Island) to the rank of a distinct species; but he proposes to distinguish it from the South Ishnd form as "Apteryz australis var. mantelli, Bartl." This opens up again the old questio vexata, "whan is a species?"

The amount of difference necessary to constitute a "species," in the generally accepted sense, is not capable of definition, and must ever remain, to a certain extent, a matter of opinion with each individual naturalist.

I haye already stated fully my reasons for keeping the two forms specifically distinct ("Birds of New Zealand," pp. 366–367); and it is sufficient for my argument that Dr. Finsch recognizes constant characters in the North Island bird of a kind to distinguish it as a permanent "variety."

I may add that I had the satisfaction of submitting good specimens of Apteryx australis and ''Ap. mantelli'' to Professor Newton, Dr. Sclater, Mr. Salvin, and Mr. Sharpe, all of whom were decidedly of opinion that the characters relied on were of sufficient importance to warrant the separation of the species.