478 MB. O. SALVIN ON THE AVIFAUNA 



Genus Geospiza. 



This genus has been placed by Gray near Coccothraustes ; but full regard being taken 

 of the strongly angulated tomia of the upper and lower jaw, I think it will be seen 

 that this is not its right position. In the formation of its bill it hardly differs at all 

 from some species of Guiraca, such as G. concreta and its allies. The legs and feet, 

 however, are much longer and stronger than in any species of Guiraca ; and the tail, 

 in proportion to the wings, is very short. The general coloration too is quite different. 

 1 feel satisfied, however, that, Geospiza has its nearest continental ally in Guiraca. 



The different states of plumage, on which Dr. Habel remarks below, are to be attri- 

 buted to the different ages of individuals. The younger birds are the lighest-coloured 

 and present the most mottled appearance ; as they get older they become darker, until 

 at last in old males the plumage is almost uniform black. The colour of the bill 

 appears to vary irrespective of age, as some black birds have light-coloured bills, 

 though in the majority of birds in this dress it is black. Younger mottled birds have 

 light-coloured bills, but in old females, just as in the males, the bill is usually black. 



Dr. Habel has supplied me with the following general remarks on the birds of 

 this genus : — 



" The colouring of all the species of this genus exhibits three styles — a black, a 

 brown, and a grey. This is the case both in male and female birds, except that the 

 plumage of the females is of a dirty brownish colour, whereas in the males it is black. 

 It would seem reasonable to divide each species into three varieties, as besides the 

 plumage the colour of the feet, as well as of the beaks, is different in these three 

 varieties. The colour of the feet varies from a light grey to black, and that of the 

 beak from yellow to brownish black. 



" Though the food of the Gcosjrizw consists chiefly of seeds of plants and trees, they 

 also feed on insects. During the ebb of the tide these birds, especially the smaller 

 species, visit the bare places, where they pick up different plants and animals of the 

 sea from amongst the stones. The reason for their resorting to such localities for food 

 is perhaps to be found in the scarcity of water more or less experienced by birds on 

 these islands. On the Island of Abingdon, where no pools of water exist, the birds are 

 dependent for water on the morning dew and the water condensed from the steam 

 which issues from the crevices of the volcanic rocks. The feathers of the faces of 

 these birds are often smeared with the gummy substance formed by the juice of the 

 Opuntia, which stands to them in the place of water." — H. 



Geospiza magnikostkis. 

 Geospiza maffnirostris, Gould, P. Z. S. 1837, p. 5 ; Darwin, Zool. Beagle, iii. p. 100, t. xxxvi. 



c^ futiginoso-niger, crisso albo nigro variegato : rostri maxilla nigra : mandibula flavo 

 variegata: long, tota (cir.) 6"0, alee 3"5, caudse 2-0, tarsi I"05, rostri a rictu 0*9. 



