GALLERY.] NATURAL HISTORY. 43 
bill lengthened, curved, and hooked at the tip ; their nostrils placed in 
a long nasal groove ; their wings are short, imperfectly formed, being 
only covered by scale-like plumes; their hind toe short and united to 
the side of the inner toe. They are found in the Antarctic regions, 
where they feed on fish, cuttlefish, Crustacea, &c. 
The remainder of the Web-footed Birds have very long wings, which 
enable them to suspend themselves in the air for a great length of time, 
so that it almost appears to be their proper sphere, as they are seldom 
seen on the ground except in the breeding season. They construct 
their nests in the clefts of rocks or on little hillocks. 
The family of Gulls (Larid^e, Cases 156—161) have the hind toe 
free, and sometimes very short and rudimentary, and a compressed bill. 
The Petrels have the bill strongly hooked at the end ; their hind claw 
is placed immediately on the tarsus, without any toe. Of all the Water 
Birds, these keep more especially out at sea; they often fly so far from 
land that during tempests they are obliged to take refuge on board the 
vessels they may happen to fall in with. They build in holes on rocks, 
and when attacked, squirt out a quantity of acrid oil from their stomachs. 
The Petrels (Pr ocellar ince, Cases 156 and 157) have the bill longer than 
the head, formed of several pieces, and acutely hooked ; their nostrils tu¬ 
bular, at the base or on the side of the bill; their hind toe is elevated, and 
consists merely of a claw. They are inhabitants of the higher latitudes 
of both hemispheres, and are almost constantly seen on the wing, only 
alighting on the ocean to take a short repose, rarely coming to land, 
except during the breeding season ; their food consists of fish, &c. The 
Gulls ( Larince , Cases 158—160) have the bill moderate, compressed, 
with the tip hooked and acute ; their nostils placed in the middle of the 
biil ; their wings very long and pointed ; their hind toe elevated from 
the ground, very small and free. They are found in every part of the 
vrorld, feeding most greedily on all kinds of animal matter, fish, &c. 
Others seek for food in the interior, which consists of worms, slugs, and 
larvae of insects. Some attack their brothers of the ocean, and cause 
them to drop or even disgorge their prey, which they then seize before 
it arrives at the water. The Skimmers ( ffliynchopince , Case 163) have 
the upper mandible much shorter than the lower; both are straight, 
very much compressed, and truncated at their ends; their wings very 
long and curved ; found in the tropical climates, where they keep in 
small flocks near the shores, or in salt, marshes, and seldom venture far 
to sea, as they are bad swimmers. They feed on small fish, skimming 
along the surface of the sea, in which they dip the lower mandible, the 
upper being elevated out of the water until the prey is felt by the lower. 
The Terns ( Sternince , Case 161) have the bill lengthened, straight, 
slender, and rather curved at the tip ; their nostrils placed near the base 
and linear; their wings very long and pointed; their legs rather short, with 
the hind toe always elevated if apparent. These birds are met with on 
almost every sea coast in the world, and occasionally proceed inland to 
the lakes, &c. They are continually seen on the wing, and sometimes 
found at very great distances from the land; their food consists princi¬ 
pally of fish, some also attack the eggs and young of water birds; 
others feed solely on insects, like the swallows. 
The family of Pelicans (PELECANiEiE, Cases 162-166) is at once dis¬ 
tinguished by the hind toe being united to the others by a web : their 
