480 



ME. 0. SALVIN ON THE AVIFAUNA 



sions is associated with any particular island, every gradation being observable in the 

 large series from Abingdon Island. Dr. Habel had especially noted tvpo birds as 

 females of black males ; and these two present almost the extremes as regards the size 

 of their bills. Both are from Bindloe Island. The following table shows the extent to 

 which this species varies in some of its dimensions. The woodcuts show the largest 

 and smallest bills I have been able to select out of Dr. Habel's series. 



The wing varies from . 

 The tail varies from . 

 The tarsus varies from 



2'9 inches to 3'3 inches, or 0'4 inch. 

 1-8 inch to 2'1 inches, or 0'3 inch. 

 0'9 inch to I'O inch, or 01 inch. 



Geospiza strenva c? 

 (Abingdon Island). 



Geospiza strenua 

 (Bindloe Island). 



Dr. Habel notes that tlie colour of the iris is brown or dark brown, the tarsus black 

 or grey, the underpart of the foot light brown or light grey, the bill brown, yellowish 

 brown, or black, the gums straw-colour, and the food chiefly seeds. 



" I felt disposed," Dr. Habel writes, " to separate two or three varieties of this 

 species, not only on account of the colour of their plumage, but also because the black 

 individuals keep apart from the others, are livelier in their movements, and quicker in 

 their flight ; they wander in small groups all over the island in which they live, uttering 

 their short, not unpleasing song from the branch of a tree. The grey and the brown 

 birds form a large flock, and search for their food in bushes or on the ground ; they are 

 slower in their movements, and utter a harsh, croaking note. Nearly all the specimens 

 I obtained were from Bmdloe and Abingdon Islands. On Indefatigable one only 

 belonging to this species, and that the only one seen, was secured. It was found 

 by the side of a small lagoon formed in the sand at high water. By filtering through 

 the sand this water had lost its salt, and could be used for cooking. Hither the birds 

 came to slake their thirst." — H. 



Geospiza dtjbia. 

 Geospiza dubia, Gould, P. Z. S. 1837, p. 6; Darwin, Zool. Voy. Beagle, iii. p. 103. 



Hah. Chatham Island (Dartvin). 



Unrepresented in Dr. Habel's collection. 



Mr. Darwin's type specimen has, since the dispersion of this Society's Museum, been 

 lost sight of, as it is not to be found in the British Museum. With Bonaparte (Consp. 



