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FAMILY IV. PALAMEDEADÆ.
Of this very limited, but widely distributed Family, very little is known. Hence their true affinities and their position in the natural system is still matter of some uncertainty. We follow Mr. G. R. Gray, who, in his “Genera of Birds,” elevates them, few as they are in number, to the rank of a Family. Some of them seem modified on the type of the Plovers, and manifest in their anatomy and other points an approach to certain Lapwings; others, again, bear a resemblance to the Gallinacea, with which they have been supposed to connect themselves through the greatfooted Megapodida. But their strongest affinities are, we think, with the Rallide, especially with the genus Porphyrio, which they resemble in their greatly developed toes, their spurred wings, and their habits of walking upon aquatic plants.
The beak is usually slender, rather short, more or less compressed at the sides, and curved downwards at the point. The wing is armed at the shoulder with one or more spurs, of a horny texture, and sharp pointed, which, where most developed, seem to be used as weapons of offence. The feet are long, as are also the legs (tibiæ), the lower portion of which is bare of feathers, and scaled; the toes are four, three before and one behind, the latter resting on the ground; the whole are greatly lengthened, and furnished with exceedingly long, straight, and pointed claws, by the expansion of which the birds are enabled to
walk with ease and celerity on the leaves of aquatic plants that float on the surface of rivers and lakes in tropical countries. Their food is believed to consist principally of the seeds and leaves of such plants as grow in the waters.
The tropical regions of South America, Africa, and Asia, are the native countries of these birds, which are found only in the vicinity of large expanses of water.
GENUS PALAMEDEA. The Screamers are large birds which are confined to the hot and teeming forests of South America. They have the beak shorter than the head, covered at the base with small feathers slightly arched, rather high at the base, tapering to the point, where it descends somewhat abruptly. The forehead is armed with a long, slender pointed horn. The nostrils are oval and open. The wings are armed with two spurs, the one large and lancet-shaped, situated on the shoulder, the other a little nearer to the tip; these are firmly fixed on a bony core : the third and fourth quills are the longest. The front toes are united at the base by a small membrane; the hind claw is very long, straight, and sharp: the tarsi are clothed with regular many-sided scales instead of transverse plates.
There is only one ascertained species, the Horned Screamer (Palamedea cornuta, Linn.), called in Brazil the Anhima, and in Guiana the Camichi or Camouche. It is larger than a goose, of a greenish-black hue, variegated on the long neck with white, and marked with a large cinnamoncoloured spot on the shoulder.
This singular bird is an inhabitant of the inundated grounds of South America, where the immense rivers overflowing their banks, cover large
tracts of flat country with sluggish water, which soon becomes choked
up with multitudinous forms of rank aquatic vegetation. In the vast swamps and morasses thus formed, which teem with the
most singular forms of animal and vegetable life, the Horned Screamer raises its extraordinary and startling voice at intervals above the incessant din of mingled cries, the croaking of myriads of frogs, and the ringing of insects. This wild scream, from which it derives its name, is said by Marcgrave to consist of the syllables vyhou, vyhou, uttered with a loud, clear, and shrill intonation.
The use of the long, slender, pointed horn with which the Screamer's forehead is furnished, is not apparent: Mr. Swainson believes that it is moveable at the base. There can, however, as Mr. Martin observes, be no possibility of mistaking the use of the shoulder-spurs. Snakes of various size, all rapacious, and all to be dreaded, abound in its haunts, and these formidable weapons enable the bird to defend itself and its young against the assaults of such enemies. If not attacked, however, the Screamer is an inoffensive bird, of shy but gentle manners. The male is contented with a single mate, and their conjugal union is said to be broken only by death.
Some writers have asserted that the Screamer feeds on reptiles; but it would rather appear, that it confines itself to the leaves and seeds of aquatic plants, to obtain which it walks on the matted floating masses of vegetation, or wades in the shallows. Its flight, as might be expected from the length and pointed character of the wings, is sweeping and powerful; on the ground its gait is stately, its head proudly erected, whence, probably, it was regarded by the older travellers, as allied to the Eagle.
The nest of this singular bird is made on the ground at the root of a tree, in which it lays two eggs, resembling those of a goose. The stomach, notwithstanding its vegetable food, is but slightly muscular: the windpipe (trachea) has an abrupt bony box or enlargement about the middle, somewhat like that of the male Velvet Pochard (Oidemia fusca). The loud and piercing character of its voice is doubtless connected with this remarkable structure.
FAMILY V. RALLIDÆ.
valuable and elaborate observations of the late Mr. Vigors on the affinities of animals, he remarks that the Rallidæ are separated from the other Families of their Order, and united among themselves, by the shape of their body, which is compressed and flattened on the sides,
consequence of the narrowness of their sternum. “If we were allowed,” continues this acute naturalist, “ to draw an inference from the analogical construction of other bodies, which move with the greater facility through the water in proportion as they assume this compressed and keel-like form, we might almost conclude that this structure, peculiar to the birds of the present Family, facilitates their progress through that element, and is intended to counterbalance the deficiency in the formation of the foot, which separates them from the truer and more perfectly formed water-birds. . . . . It is certain that the greater portion of these birds are excellent swimmers; and in such habits, as well as in the shortness of their tarsi, which is equally conducive to