ZOSTEROPS. 
The bill is short, shorter than the head, conical, pointed, tip sharp, fairly 
slender, culmen gently arched, basally keeled, depth of both mandibles at the 
base about equal to its width ; nostrils a linear slit in a short nasal groove, 
a prominent operculum present; no nasal bristles, but the feathers of the 
fore-head encroaclung a little on the nasal groove ; lower mandible not quite 
as stout as the upper, the interramal space triangular, short, feathered, less than 
half the length of the mandible ; rictal bristles weak and obsolete ; tongue 
brushed; the wing long, with the feathers narrow, the secondaries fairly 
long; in the typical species the first (really the second) primary is about equal 
to the fourth, longer than the fifth and a little exceeded by the second and third, 
which are subequal and longest; the real first primary is very minute, entirely 
hidden by the coverts ; not the outer primary, but the succeeding three, are 
incised on their outer webs for the apical half. 
The tail is long, straight, almost emarginate ; the upper tail-coverts long, 
extending more than half the length of the rectrices. 
The legs are comparatively short and slender, the front of the tarsus more 
or less boldly scutellate, five scutes being counted, the hinder part bilaminate, 
the outer lamina with a tendency to fusion with the acrotarsium ; the toes 
delicate, the claws small, the hind-toe a little stronger with a stouter claw ; 
the hind-toe and claw a little less than the middle toe and claw, the inner 
toe a little less than the outer, but with claw just reaching to the length of the 
middle-toe alone; the toes are almost free from each other basally. 
As pointed out by Castelnau and Ramsay, their Z. gulliveri has a much 
more rounded wing than the typical Zosterops, and I find that my Z. albi- 
ventris cairncrossi is even more rounded, the primaries being only a little longer 
than the secondaries and equal to the seventh ; the second, third, and fourth 
subequal and longest, but the fifth and sixth very little shorter. In this form 
the tarsus is comparatively weaker and anterior toes more delicate, but the 
hind-toe stouter. I have proposed the subgeneric name Imteozosterops to 
indicate this difference. 
Apparently the immature birds resemble the adult. 
Key to the Species. 
Back grey; throat grey or only tinged with yellow 
Throat and under tail-coverts yellow" 
Back green, throat only yellow 
All under-surface yellow 
lateralis 
albiventris 
australasice=gouldi olim 
lutea 
135 
