32 DERIVATION OF THE FLORA OF HAWAII 



VERTEBRATES 



FISHES 



Dr. David Starr Jordan has informed the writer that the shore fishes 

 of Hawaii are related to those of the Southern Pacific and not to Ameri- 

 can types. Such fresh-water species as are certainly indigenous have 

 been derived from marine species that have migrated into fresh water 

 and therefore throw no light upon the question of a possible former land 

 connection. 



REPTILES 



No indigenous amphibia are known in Hawaii. This absence may 

 perhaps be explained on the assumption that the isolation of the islands 

 took place at a period prior to the time when the modern amphibia, frogs 

 and toads, were developed. A similar condition exists in New Zealand, 

 where but a single species is known. 



Of the reptiles proper, there are seven species, four Geckos and 

 three Skinks. They differ little if at all from widespread species of the 

 Southern Pacific regions, and it is thought they possibly may have been 

 introduced through human agency. It has been thought, also, that they 

 may have reached the islands by drift. 



BIRDS 



The birds of Hawaii are of extraordinary interest, and have been 

 carefully studied. Perkins 36 says that except for a comparatively small 

 number of migratory species, wide-ranging sea-birds and occasional 

 stray visitors, all the species are peculiar to the archipelago. All the 

 species of passerine birds are endemic, and most of them confined to the 

 mountain forests. 



Perkins records forty-nine species of passerine birds, of which all 

 but one, a species of crow (Corvus), belong to genera peculiar to Hawaii. 

 Forty of the forty-nine species of passerine birds belong to a peculiar 

 family, Drepanididae, quite unknown outside the archipelago, and so 

 specialized as to make its relationships problematical. Wallace 37 thinks 

 the family most nearly related to the Flower-peckers (Dicaeadae), widely 

 distributed through Australasia and the Old World tropics. Gadow 38 

 suggests the Coerebidae, an American family, as the nearest relatives of 

 the Drepanididae; but in view of the predominance of Asiatic and Aus- 



36 "Fauna Hawaiiensis," 1, 368-465. 



" "Geographical Distribution of Animals," 2, 277-278. 



Perkins, loc. cit., p. 382. 



