484 MR. O. SALVIN ON THE AVIFAUNA 
adult. In this the crissum is nearly pure black, the feathers being very narrowly edged 
with white. The bill, as pointed out by Mr. Gould, has a distinct tooth-like prominence 
in the middle of the cutting-edge of the mandible on either side. The female is darker 
than is usual in other Geospize. 
Of G. dentirostris Dr. Habel says: —‘ Usually seen in groups of families, frequenting 
low bushes in search of fruit, the members uttering a cheerful chirping note. In the 
morning they visit the bushes growing near the shore; later in the day they retire more 
inland. I only met with this bird on Abingdon Island, where it predominates over 
the other species in numbers.” —/Z. 
Before passing to the next genus I will recapitulate the measurements of all the 
above species of (eospiza, except G. nebulosa and G. dubia, of which our knowledge is 
as yet incomplete, and also G. dentirostris, which seems to have distinct characters of 
its own. 
G. magnirostris. G. strenua. G. fortis. G. fuliginosa. G. parvula. 
inches. inches. inches. inches. inches. 
Wing; 26.1315 3°3-2'9 2°95-2'5 2°55-2°25 240-215 
Dail ce 2:0 2-1-1°8 1°85-1°5 1°65-1°4: 1:50-1°3 
Tarsus . . 1:05 1:0-0°9 0:90-0'8 0:85-0°7 0°72-0°63 
Of all except G. magnirostris the largest and smallest measurements are given. 
From this table it will be at once seen that the gradations from the largest to the 
smallest species are quite complete, and that the only grounds for separating them at 
all rests upon the dimensions of the bill, where the steps are not quite so gradual. 
But the dimensions of the bills furnish but slender specific characters, as will be seen 
by the accompanying cut. 
A “s<= 
. ~ 
wis 
G. fortis. G. fuliginosa. G. fuliginosa. G. parvula. G. parvula. 
The important and indisputable fact remains that whether we treat Geospiza as 
including one highly variable species, or as comprising several in themselves variable 
