Winter 
plumage. 
Young. 
438 NATATORES. FRATERCULA. 
Fig. 2. In the winter plumage. 
The space between the bill and eyes, crown of the head, 
and nape of the neck, brownish-black, with a slight ci- 
nereous tinge. The white streak on each side from bill 
to eye, not so distinct as in the summer plumage, and 
in young birds scarcely visible. Ear-coverts, cheeks, 
sides of the neck and under plumage, white. Upper 
plumage black. Wings as in the summer. 
In the young of the year the bill is black, and the fur- 
rows very slight, acquiring their marked character on- 
ly as the bird gains age. 
Genus FRATERCULA, Briss, PUFFIN. 
GENERIC CHARACTERS. 
Brit shorter than the head, arched, deeper than long, the 
base of it occupying the whole length of the face, very much 
compressed, having both mandibles transversely furrowed, 
and with their tips notched. Lower mandible entire, with- 
out Gnathidie; the keel projecting beyond the line of the 
chin; angle ascending. Corners of the mouth having a star- 
shaped dilatable skin. Margin of the base of the upper 
mandible thickened or swollen. Nostrils basal, placed close 
to the lower edge of the upper mandible in the form of a 
~ marrow slit. 
Wings short, narrow, and acuminate. ‘Tail very short, 
consisting of sixteen feathers. 
Legs abdominal, short; the tarsi only free. Feet of three 
toes, palmated ; outer toe nearly as long as the middle, and 
longer than the inner one. Claws hooked ; that of the inner 
toe the most so, and very sharp; middle claw the longest. 
In this genus the depth and lateral compression of the bill 
is carried to a still greater extent than in the genus Alca, 
with which its members were associated by many of the ear- 
lier systematists. Its construction is very different, the lower 
