NATATORES. SULA. 453 
PLare 86. Represents a Male of this species (killed near the 
Fern Islands) in the nuptial plumage, or with the fron- 
tal crest fully developed. Natural size. 
Head, neck, lower part of the back, and under plumage, ou 
fine silky blackish-green. Upon the forehead is a tuft tion, se 
of blackish-green elongated feathers, upwards of two Summer 
inches long, and curving forwards. Mantle, scapulars, a 
and wing-coverts deep-black, bronzed green, each fea- 
ther being surrounded by a band of velvet-black. Tail 
consisting of twelve feathers, scarcely six inches long, 
black, with the shafts strong and elastic; the webs 
coarse, and generally much worn at their tips. Legs 
and toes black. Guttural skin and corners of the mouth 
gamboge-yellow, the former having black specks. Bill 
black ; two inches and three-eighths in length from the 
forehead to the tip. 
In autumn, and the early part of winter, it is destitute of 
the frontal elongated feathers, but in other respects the 
plumage is the same as in summer. Both sexes are 
nearly alike.-—The young of the year have the head and Young. 
neck of a greyish-black, tinged with green, and the un- 
der parts are more or less mixed with greyish-white. 
The upper plumage inclines to greenish-brown, and the 
zone that margins each feather is broader than in the 
adults. 
Genus SULA, Briss. GANNET. 
GENERIC CHARACTERS. 
Bitt longer than the head, thick, strong, strait, acumi- 
nate, compressed towards the point, with the dertrum slightly 
convex. Mandibles equal; the upper one laterally sulcated 
from the base to the tip, and with a hinge near the posterior 
part, making it to appear as if composed of five separate 
pieces. Culmen rounded. Lower mandible having the 
