XXXVIli INTRODUCTION. 
Order ALC 4. 
Family ALCID. 
Subfamily ALCINA, 
Auca, Lizneus.—Bill straight, large, compressed, very much decurved towards 
the point, basal half of both mandibles covered with feathers, grooved towards 
the point, the superior mandible hooked, the under one forming with it a 
salient angle. Nostrils lateral, marginal, linear, near the middle of the beak, 
the aperture almost entirely closed by a membrane covered with feathers. 
Wings short. Tail pointed. Legs short, very far back ; only three toes, all 
in front and entirely webbed ; claws slightly curved (p. 695). 
URIA, &rtsson.—Bill of moderate length, strong, straight, pointed, compressed ; 
upper mandible slightly curved near the point, with a small indentation or 
notch in the edge on each side. Nostrils basal, lateral, concave, pierced 
longitudinally, partly closed by membrane, which is also partly covered with 
feathers. Wings short, first quill the longest. Tail shorter than in Ada. 
Legs short, slender, placed behind the centre of gravity in the body ; only 
three toes, all in front and entirely webbed (p. 699). 
MeERGcuLUus, Vzed//ot.—Bill shorter than the head, thick, broader than high at the 
base ; culmen arched ; upper mandible indistinctly grooved, under mandible 
with the symphysis very short and oblique ; the tips of both notched ; com- 
missure arched. Nostrils lateral, round, situated at the base of the bill, and 
partly covered with small feathers. Wings and tail short. Legs far bac, 
short ; three toes, all directed forward and united by a membrane (p. 705). 
Subfamily FRATERCULINA. 
FRATERCULA, Srzsson.—Bill higher than long, much compressed ; both mandibles 
arched, transversely grooved, notched towards the point. Nostrils lateral, 
naked, almost closed by a membrane. Wings and tail short. Legs far back ; 
feet with three toes, all in front and fully webbed ; claws curved (p. 707). 
Order PYGOPODES. 
Family COLYMBIDE. 
CotymBus, Lzvneus.—Bill about as long as the head ; strong, straight, rather 
compressed, pointed. WNostrils basal, lateral, linear, perforated. Wings 
short, the first quill the longest. Tail short and rounded. Legs thin, 
compressed, placed very far backwards, and closely attached to the posterior 
part of the body ; three toes in front united by membranes, one tue behind 
with a small membrane, articulated upon the tarsus ; claws flat (p. 709). 
Family PODICIPEDID. 
Popicipes, Latham.—Bill of moderate length, straight, hard, slightly com- 
pressed, pointed, forming an elongated cone. Nostrils lateral, concave, 
oblong, open in front and perforated, closed behind bya membrane. No true 
tail. Wings short, first three primaries nearly equal and the longest in the 
