438 XATATORKS. FRATERCULA. 



Fig. 2. In the winter plumage. 



Winter The space between the bill and eyes, crown of the head, 

 plumage. an( j na p e o f ^ nec ]^ 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. 



Young. 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. 



BILL 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 Gnathidia; 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 

 narrow 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 



