THE BIRDS 211 
chick (Podilymbus podiceps), for example, found abundantly 
on the larger lakes and streams throughout the United 
States, captures its food, sleeps, and breeds without leaving 
the water. The loons living in the same situations as the 
dabchick are also remarkable swimmers and divers. Of 
the three species found in this country, the common loon 
or diver ( Gavia imber) attains a length of three feet, and is 
otherwise distinguished by its black plumage, mottled and 
barred with white, which is also the color of the under 
parts. The auks, murres (see frontispiece), and puffins are 
marine, and, like their inland relatives, are expert swim- 
mers and divers, strong fliers, and spend much of their 
time on the open sea. During the breeding-season they 
assemble in vast numbers on rugged cliffs along the shore, 
and lay their eggs on the bare rock or in rudely constructed 
nests. 
198. The gulls, terns, petrels, and albatrosses (Longi- 
pennes).—The birds belonging to this group are among the 
most abundant along the seacoast, and several species make 
their way inland, where they often breed. All are char- 
acterized by long, pointed wings and pigeon or swallow-like 
bodies, which are carried horizontally as the bird waddles 
along when ashore. Many are excellent swimmers and 
powerful fliers, especially the petrels and albatrosses, which 
sometimes travel hundreds of miles at a single flight. 
The gulls are abundantly represented along our coasts, 
where they frequently associate in companies, usually rest- 
ing lightly on the surface of the water, or wheeling lazily 
through the air on the lookout for food. The terns are 
of lighter build than the gulls and are more coastwise in 
their habits, and are further distinguished by plunging like 
a kingfisher for the fishes on which they live. Both the 
gulls and terns breed in colonies, every available spot over 
acres of territory being occupied by their nests, which are 
usually built of grass and weeds placed on the ground. 
The petrels and albatrosses are at home on the high 
