40 
Allen’s naturalist’s library. 
inches, but without anything like regularity of form ; the top is 
nearly flat, there being but a very slight hollow to prevent the 
egg rolling off. The nests are so completely plastered with 
the excrement of the birds, that at first sight it appears tu be 
almost the only material ; they are either placed on the ground, 
in a clear open space, or on the tops of the thick scrub, over 
those of S. fuliginosa. These two species, the Noddy and 
the Sooty Tern, incubate together in the utmost harmon}’, 
the bushes to an immense extent wearing a mottled appearance 
from the great mass of birds of both species perched on the 
top, the male Sooty Tern sitting quite close to the nest of the 
Noddy, whilst its mate is beneath, performing her arduous 
duties of incubation. (Cf. Gould’s Handb. B. Austr. ii. p. 413). 
Sometimes no nest is made and the egg is placed in a crevice 
of rock or coral-reef. 
Eggs. — One only, according to the observations of all recent 
observers. Audubon gives the number as three. They 
are similar to those of the Sooty Tern, and of the same 
character, but they are always much paler and never exceed a 
light stone-colour, the spotting being much more sparsely 
distributed and smaller; the type with scratclies or zig-zag 
markings appears to be absent. On tlic other hand, there are 
one or two eggs in tlie British Museum which have distinct 
blotches, confluent at the larger end, and in one example, the 
large end of the egg is taken up by an immense patch of red- 
dish-brown. Axis, 2’o5-2‘i5 inches; diam. i '4-1 -55, 
Mr. Saunders points out that the yolk of the Noddy’s 
egg is yellow, while that of the Sooty Tern is deep orange- 
red. The Hon. Walter Rothschild also calls attention to the 
fact that the inside of the Noddy’s egg is darker and more 
green when held up to the light. 
THE GULLS. SUB-FAMILY LARINHi:. 
In the Gulls, the bill is what is called “ epignathoiis,” 
the upper mandible being longer and bent down over the 
tip of the lower one ; tail usually square, seldom forked, 
exceptionally cuneate. (Cf. S.iunders, Cat. B. Brit. Mus. xxv, 
p. 4 (1895).) 
