294 BRITISH BIRDS. 



only sit on a single egg ; but this is, no doubt, the result of the constant 

 robbery of the eggs, which is continued until the power of producing them 

 is almost exhausted. Hume, who found this bird breeding on the Laccadive 

 Islands, says that three is the full clutch. We can fortunately form some 

 idea of the wonders of " Wide-awake Fair," as the great breeding-ground 

 on Ascension Island is called, since it has been photographed in the height 

 of the season, and various accounts have been published of the extraordi- 

 nary scene Collingwood, ' Zoologist/ 1867, p. 979 j Sperling, ' Ibis/ 1868, 

 p. 286 ; and Penrose, ' Ibis/ 1879, p. 272. The fact that the Sooty Tern, 

 if not molested, will lay three eggs is also confirmed by Audubon, who 

 found it breeding on the Tortugas Islands. 



The eggs of the Sooty Tern vary in ground-colour from white to pale 

 buff; the surface-spots are reddish brown, and the underlying spots are 

 pale brown. The markings are generally evenly distributed over the 

 surface of the egg, occasionally somewhat sparsely so, and not unfrequently 

 displaying a tendency to form a zone round the larger end. The spots are 

 generally small, ranging from the size of buckshot downwards. The eggs 

 vary in length from 2'1 to 1'8 inch, and in breadth from 1*5 to 1*35 inch. 

 They approach nearest to certain varieties of the Sandwich Tern ; but 

 although the spots on some examples of the eggs of the Sandwich Tern may 

 be no larger in size, they are always darker in colour. 



The Sooty Tern is almost as large as the Sandwich Tern, but has a 

 shorter wing and a much longer and more deeply forked tail. It belongs to 

 a different group to any of the Terns hitherto described, although it agrees 

 with the Lesser Tern in the distribution of the black and white on the 

 head, and probably also in the fact that the winter plumage does not differ 

 from that of summer. The whole of the under surface of the body, 

 including the under wing-coverts and the outer tail-feather on each side, 

 is white, slightly suffused with slate-grey on the belly, under tail-coverts, 

 the tips of the outer tail-feathers, and the under wing-coverts. The white 

 on the breast extends to the sides of the neck, and almost, but not quite, 

 meets on the nape at the termination of the black cap ; the rest of the upper 

 parts are sooty black. Bill, legs, and feet black ; irides hazel. Young in 

 first plumage are sooty brown, slightly paler on the underparts, the feathers 

 of the mantle, the scapulars, innermost secondaries, upper tail-coverts, and 

 tail having white tips. The intermediate stages of plumage are imperfectly 

 known. 



Young in down have the upper parts brownish grey and the underparts 

 white. 



Two other tropical species of Tern, the Smaller Sooty Tern (Sterna 

 ancestheta) and the Noddy Tern (Sterna stolida], have been admitted into 

 the British list upon what appears to be insufficient authority. Of the first 

 of these species an example is recorded (Sauuders, ' Zoologist/ 1877, 



