8G (Japt. F. W. Ilutton on the Geograplilcal 



the species [D. capensh) that occurs at the Cape of Good 

 Hope. The occiUTence of G. hrevirostris and G. melanoleucus 

 in New Zealand presents a parallel case to the two species of 

 stilt-plover, with, however, this difference — that, judging from 

 the colours of the young bird, it is probable that G. melano- 

 hucus has been derived from G. hrevirostris owing to its having 

 been isolated in Australia, and that its descendants have 

 migrated back again to Ncav Zealand. 



Of the gulls we possess a species [Larus jpomare) which is 

 found nowhere else — a peculiarity of which few countries can 

 boast, but which can perhaps be accounted for by the fact that 

 this gull only frequents freshwater lakes and seldom comes 

 doAvn to the sea. Our other gulls are widely spread ; but it is a 

 most remarkable fact, which at present appears to me to be 

 quite inexplicable, that neither gulls nor cormorants occur in 

 any of the Polynesian islands. 



Of ducks we possess nine species, four, or perhaps five, of 

 which are endemic — one, the blue duck [Hymenoh^mns ma- 

 lacorhynchus)^ belonging to a curious genus found only in New 

 Zealand, but related to a genus [MaJacorhynchus) in Australia. 

 The others are all found in Australia — one [Pterocyanea gih- 

 herifrons) ranging through New Caledonia and the Indian 

 archipelago, and anotlier, the common grey duck [Anas super- 

 ciliosa) , spreading over Polynesia as far north as the Sandwich 

 Islands. The most remarkable circumstance connected witli 

 our ducks is the presence of a species of Fuligula, a genus 

 found neither in Australia nor Africa, but belonging properly 

 to the northern parts of America, Europe, and Asia, although 

 one species is found in South America. The occmTcnce, how- 

 ever, of a northern species {F. cristata) in the Pelew Islands 

 points out to us perhaps the route along which the ancestors 

 of our species travelled. 



The Chatham Islands possess thirty-two species of birds 

 (omitting the gulls, penguins, and petrels), of which six are 

 found nowhere else. All the others are found in New Zealand, 

 except the shining cuckoo [C. plagosus)^ wliicli, as already 

 stated, migrates to and from Australia. No genus, however, 

 is peculiar to these islands, except perhaps a rail {RaUus ? 

 modestus) which is evidently incapable of flight, and which 

 will probably liave to be placed in a genus by itself. This 

 curious form must not, however, be regarded as a change pro- 

 duced by long isolation, but rather as an old form preserved 

 from destruction by isolation. The most noticeable cir- 

 cumstance in the Chatham-Island fauna is the absence of 

 Raptores, with the exception of an occasional visit from 

 the harrier {Circus GouJdi), which does not, however, appear 



