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-grev 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. 1 3.), but the upper plumage of that is 
described as “ obscui-e cinereis." 
