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 to 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 harmony, 

 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 scratches or zig-zag 

 markings appears to be absent. On the other hand, there are 

 one or two eggs in the 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. 1*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 LARIN.E. 



In the Gulls, the bill is what is called " epignathous," 

 the upper mandible being longer and bent down over the 

 tip of the lower one ; tail usually square, seldom forked, 

 exceptionally cuneate. (Cf. Saunders, Cat. B. Brit. Mus. xxv, 

 p. 4 (1895).) 



