118 Transactions. — Zoology. 



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 to me, to adopt the older name of R. i^^t'^^WP^nsis, 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 II. hyhrida, 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 pachyrliynchus, Gray. 



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



Apteryx miantelli, 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 distrnguish 

 it from the South Island form as " Apteryx australis var. mantelli, Bartl." 

 This opens up again the old quoistio vexata, " what is a species T 



The amount of difierence necessary to constitute a " sjDecies," 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 have already stated fully my reasons for keeping the two forms 

 specifically distinct (''Birds of New Zealand," pp. 366 — 367) ; and it is sufiicient 

 for my argument that Dr. Finsch i-ecognizes 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. 



