302 
VERTEBEATA. 
ally in Florida. It is sometimes called Courlan and also Aramus. It feeds on frogs and insects, 
lives alone or in couples, perches on elevated trees, and lias a piercing cry of carau, carau^ carau^ 
wliicli may be lieard for half a raile. 
GUIiLS, ETC. GUILLEMOT. SNAKE-BIED. CORMORANT. CRESTED PENGUIN. FRIGATE-BIRD. 
ORDER 8 NATATORES. 
The most striking character of the Natatores, or Swimming-Birds, is derived from the structure 
of the feet, which are always palmate, that is, furnished with webs between the toes. There are 
always three toes directed forward, and these are usually united by a membrane to their extremi- 
ties ; but in some cases the membrane is deeply cleft, and the toes are occasionally quite free, and 
furnished with a distinct web on each side. The fourth toe is generally but little developed, and 
often entirely w^anting ; when present it is usually directed backward, and the membrane is some- 
times continued to it along the side of the foot. These webbed feet are the principal agents by 
which the birds propel themselves through the water, upon the surface of which most of them 
pass a great portion of their time ; and by the same means many species dive to a considerable 
distance below the surface in search of their food, which consists almost entirely of fish, mollusca, 
and other small aquatic animals. The feet are generally placed veiy far back, a position which 
is exceedingly favorable to their action in swimming and diving, but which renders their progres- 
sion on the land somewhat awkward. In some instances the feet are situated quite at the hinder 
extremity of the body, which then assumes an upright position when on land. 
The body is generally stout and heavy, and covered with a very thick, close, downy plumage, 
which the bird keeps constantly anointed with the greasy secretion of the caudal gland, so that 
it is completely waterproof. The wnngs exhibit a very great variety in their development. In 
the Penguins they are reduced to a rudimentary condition, destitute of quills, and covered with a 
scaly skin, forming flat, fin-like organs ; while in some other species the wings are of vast size and 
power, and the birds pass a great part of their lives in the air. Between these two extremes we 
meet with every intermediate degree of development. Those species which are endowed with 
the greatest power of flight are usually incapable of diving, although they frequently take their 
j)rey by plunging suddenly into the water, from the air. 
The form of the bill is also very variable : in some it is broad and flat, in others deep and com- 
