KEY TO FAMILIES. — WATER BIRDS. 21 
GROUP 5. 
Toes, three, full webbed; no hind toe. 
Nostrils, separate, not opening into one double-barrelled tube; upper mandible, curved 
near tip; bill, yellowish, or greenish yellow; an indication of a hind toe, in the form of a 
Cm small knob without nail; tail, entirely white, or 
a= x \ white with black band near tip. This is the only 
= 4 North American gull lacking a hind toe. 
- Kore Family LARIDAE (Larus tridactyla). 
Kittiwake Gull. 
See page 36. 
Bill, reddish (in life showing also yellow and blue), 
peculiar in form, suggesting that of parrot. 
Family ALCID. 
Subfamily FRATERCULINA:, Puffins. 
See page 30. 
Bill, black, with narrow white band. 
Family ALCIDA:. 
Subfamily ALCINZE. Auks. 
See page 30. 
= = Bill, black or brownish; wing, ze 
over 7.25 inches long, carpus (bend Ai 
' of wing) to tip. eS 
ae, Family ALCID. ae 
tox Subfamily ALCIN=. ae 
ig — Murres. 
a a 2 See page 30. = 
— 
a 
— 
Bill, black, or blackish; wing, less than 7.25, but more than 5.50, measured, carpus to tip. 
Family ALCIDAZ. Subfamily PHALARIN-E. Guillemots. 
° See page 30. 
