402 Transactions. — Miscellaneous. 



of finches, which formed the greater number of the species of birds found on 

 the islands, he had sufficient reasons for believing that some of the species 

 of the sub-group Georpiza were confined to separate islands. 



The occurrence of a similar peculiarity in the distribution of a considerable 

 proportion of the birds of New Zealand, struck me whilst engaged in prepar- 

 ing the tables annexed to my former paper, and at the same time drew my 

 attention to the fact that the features which so much impressed Mr. Darwin 

 in connection with the organic productions of the Galipagos, also charac- 

 terized to a large extent those of New Zealaud. In order that you may be 

 enabled to appreciate this peculiarity, I propose to call your attention to 

 some of the more remarkable instances in the case of the avi-fauna and 

 flora. 



Beginning with the case of the birds, you will find, on reference to 

 table hi., annexed to my last" year's paper, that there are eighteen species 

 peculiar to the main islands of New Zealand, nine peculiar to the North 

 Island, and sixteen peculiar to the South Island. Of the species peculiar 

 to the North Island, there is only one belonging to any genus which con- 

 tains more than one species and is represented by other species of the same 

 genus in both islands. Of those peculiar to the South Island, there are six 

 belonging to genera which contain more than one species, and are repre- 

 sented by species in both islands, but these six comprize two species of 

 Nestor and two of Apteryx. 



The eight species which remain in the North Island belong to genera 

 not represented by any common form in both islands, and ten of the species 

 peculiar to the South Island are similarly unrepresented ; and yet, of the 

 nine species peculiar to the North Island, we have seven which are repre- 

 sented by allied species in the South Island, whilst except the South Island 

 species so represented in the North Island, none of the remaining nine are 

 represented by species in the latter island. 



The remarkable character of this distribution becomes even more strik- 

 ing, when attention is called to some of the special instances. Take, for 

 example, the case of Orthonyx albicilla, the North Island form of the genus, 

 and compare it with Orthonyx ochrocephala of the South Island. To the 

 eye no two birds can be more distinct, and yet in their notes, in their move- 

 ments, in their mode of feeding and in their nesting, these birds are 

 practically undistinguishable, indicating unmistakably their descent from a 

 common ancestor. Singularly enough, however, the North Island bird is 

 found frequenting the thickets in the rich and varied forest down to sea- 

 level, whilst the South Island one is rarely found outside of the Fagus 

 forest, or below an elevation of 500 or GOO feet. Still the curious fact 



