405 
of the United States . 
base, ridge deeply grooved each side, edges dilated, sharp, 
entire : nostrils in the farrows, basal, linear, obsolete : 
tongue very short, lanceolate : gape very wide : orbits and 
lores naked : throat dilatable, pouch large. Head moderate ; 
eyes large : neck moderate : body compressed, elongated. 
Feet very short, drawn up into the belly; tibiae wholly 
feathered ; tarsus one third shorter than the outer toe, much 
compressed, carinated before and behind, half feathered ; toes 
long, semipalmated, the connecting membrane being deeply 
indented ; second much the longest ; outer longer, but 
subequal to the inner, edged exteriorly by a small mem- 
brane ; hind toe half as long as the middle; nails large, 
curved, acute : middle serrated on the inner edge, twice as 
large as the others. Wings extremely long, very narrow ; 
first primary longest, the others decreasing successively very 
much. Tail deeply forked, of twelve flaccid feathers. 
Female similar to the male. Young differing from the 
adult, and changing repeatedly. Moult twice a year, chang- 
ing somewhat in color. Plumage not water proof. Colors 
black. 
Tyrants of the ocean. Associate in small flocks. Keep 
constantly on the wing, flying swiftly against the strongest 
gales, and rising above the clouds. Easily distinguished at 
a distance. Traversing rapidly vast spaces, and appearing 
farthest at sea, though hardly able to rest on the water 
on account of the nature of their plumage. Never dive 
nor swim. Resting only on trees, or on high rocks : unable 
to rise, and easily caught when on the ground. Following 
large voracious fishes in pursuit of small ones, in order to 
catch the latter as they leap out of water, often seizing the 
pursuer himself. Prey also on the Pelicans, but especially 
on the Gulls and Boobies, which they compel, always keep- 
ing above them, to drop the fruits of their industry, or even 
to disgorge what they had swallowed, seizing it before it 
reaches the water. Flight very rapid. Sight very keen. 
Vol.IL 51 
