480 MR. O. 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 two 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. . . . 2:9 inches to 3°3 inches, or 0-4 inch. 
The tail varies from . . . . I:8inchto 2-1 inches, or 0°3 inch. 
The tarsus varies from . . . O9inchto J:Oinch, or 0:1 inch. 
Geospiza strenua 
Geospiza strenua g (Bindloe Island), 
(Abingdon Island). 
Dr. Habel notes that the 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. 
“J 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 Bindloe 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 DUBIA. 
Geospiza dubia, Gould, P. Z.S. 1837, p.6; Darwin, Zool. Voy. Beagle, iii. p. 103. 
Hab. Chatham Island (Darwin). 
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. 
