248 CRESTED TERN. 



their descriptions are faulty or imperfect, and they 

 thus become as useless as if they never had existed. 



The species now before us is one of the largest 

 sized in this genus, measuring no less than twenty 

 inches. The upper plumage, but for a very slight 

 tinge of grey, hardly perceptible, might be termed 

 as white as the under parts, the quills alone being 

 grey, frosted, as it were, with white ; the bill is rich 

 orange, rather longer, but not so stout as that of the 

 gull tern. The deep black upon the head and front 

 includes half the lores and the eyes, but it is inter- 

 rupted by a white spot on the lower eye- lid ; the 

 feathers of the hind head and nape are lengthened 

 and pointed, so as to form a nuchal crest ; the wings 

 are long, and reach to the end of the tail : the first 

 five quills are light-grey, with a frosted white ap- 

 pearance on their outer webs, the inner webs are 

 dark-grey on their inner half and white on their 

 outer; but the stripe of this latter colour almost 

 disappears on the fourth and fifth quills, whose inner 

 shafts are almost entirely dark-grey, excepting a 

 narrow white edging : the remainder quills are uni- 

 form whitish, except a stripe of light-grey on the 

 outer webs of the secondaries : the tail, which is 

 deeply forked, is white both above and beneath. 

 The feet are deep black, and are naked for nearly 

 an inch above the tarsus *. 



Total length, 20 ; bill, from the gape, 3| ; front, 



* This bird makes the nearest approach to the Sterna velox 

 of Riippell (Atlas, pi. 13.), but the upper plumage of that i* 

 described as " obscure cinereis" 



