VIPERIDIE, family of snakes constituting with Crotalidx, the Viperina, or third sub-order of Ophidia. The general characteristics of viperidze are wide angular depressed head, caus ing the neck to appear small in comparison; short, thick body; and tail tapering suddenly to a point. In some of the largest vipers, the short, unmistakable tail is only two inches in length. The head is mostly covered with scales, rarely plates, or only a few about the eyes and lips, or with extremely fine plates. The scales are carinated, often rough, even spincus. The ventral shields are broad, and the subeaudal plates in two row's. The nostrils are large, and in some species they close with a valve. This highly venomous family of serpents arc furnished with a pair of long, curved fangs. In this order the upper maxillary, bearing two isolated fangs firmly fixed to it, is reduced to a mere wedge of bone, which is movably. articulated, and by especial muscles rotates or rocks to and fro, and the fang with it. The action is volitional as a whole. The viperine 3nakes are often said to have "movable" fangs, though the fangs themselves do not move in dependently, hut only with the bone to which they are attached. Thus, when at rest, the fang, protected by a membranous sheath, lies supine along the jal,v; but when in use springs down by the rotation of the maxillary hone, just as a scythe might point downward or hori zontally by the movement of the handle. The fang has a canal in its interior, connected with a poison gland, whose contents are ejected into the wound made by the fang in the act of biting. Behind the pair of functional fangs, others, in a ructimentary stage, arc found, and may even create a wound, though, being as yet unconnected with the poison-duct, they do not convey venom into the wound. The lower jaw has numerous solid teeth of the ordinary form. Formerly the vipers were
confounded with colubrine snakes, and even at the present day authorities differ in the ar rangement of genera and species, on account of the forms running so much into each other. Dumeril gives six genera and 17. species; Wal lace, three genera and 22 species, and Gray nine genera and 20 species. Strauch gives three genera; Vipera (with 20 species), &his (with one species), and Atheris (with three species). Those of the family best known are the °River Jack" of western Africa, the Horned Viper or Cerastes (q.v.) of northern Africa and West ern Asia. the Puff Adder of Africa, the Death Adder of Australia, Russell's Viper and the Carpet Sfialce of India. The cobra de capello and the Egyptian Naja haje also belong here. The viperida, as above mentioned, are mostly distinguished by their broad fiat, angular head; thicic, heavy body; short, tapering tail; rough, carinated scales, and a generally hideous physiognomy, which seems to express their noxious qualities. Nevertheless some have a handsome exterior and are adorned vvith dark, rich colorings and patterns. The Daboia of India is one of these, ,and, being of less clumsy form, has been named Vipera elegans. The true vipers, or those which have not the nasal fosse, are most largely represented in Africa, which has about 12 species. Europe has three, Inclia two. The anomalous Death Adder (Aeanthophis antarctica) of northern Australia, with its unmistalcably venomous look, is included among the vipers, nowithstanding it has a pair of fixed fangs like the The largest and deadliest species are found in tropical countries. They itdrabit dry, sandy deserts, and are of retiring, sluggish nature. See LACHESIS ASP; PUFF-ADDER j RAMS SNAKE, etc.