Page:Encyclopædia Britannica, Ninth Edition, v. 22.djvu/211

 SNAKES 195 snakes lack a special apparatus for breaking the shell. The Indian cobra also is said to rob birds of their eggs. The Tree Snakes (Dendrophidx) are among the greatest ornaments of tropical fauna. The graceful form of their body, the elegance and rapidity of their movements, and the exquisite beauty of their colours have been the admiration of all who have had the good fortune to watch them in their native haunts. The majority lead an exclu- sively arboreal life ; only a few descend to the ground in search of their food. They prey upon every kind of Fio. 10. Indian whip snake. Passerita mycterizans. arboreal animal, birds, tree-frogs, tree -lizards, etc. All seem to be diurnal, and the larger kinds attain to a length of about 4 feet. The most beautiful of all snakes are perhaps certain varieties of Chrysopdea ornata, a species extremely common in the Indian Archipelago and many parts of the continent of tropical Asia. One of these varie- ties is black, with a yellow spot in the centre of each scale; these spots are larger on the back, forming a series of tetrapetalous flowers ; the head is similarly ornamented. Another variety has a red back, with pairs of black cross- bars, the bands of each pair being separated by a narrow yellow space ; sides brown, dotted with black ; belly dark green, the outer portion of each ventral shield being yellow, with a blackish spot. The features by which the tree snakes are distinguished Whip are still more developed in the family of Whip Snakes snakes (Dryophidae), whose excessively slender body has been compared to the cord of a whip. Although arboreal, like the former, they are nocturnal in their habits, having a horizontal instead of a round pupil of the eye. They are said to be of a fierce disposition, feeding chiefly on birds ; and indeed a long tooth placed about the middle of the maxillary seems to assist them much in penetrating the thick covering of feathers and in obtaining a firm hold on their victims. In some of the species the elongate form of the head is still more exaggerated by a pointed flexible appendage of the snout (Passerita), which may be nearly half an inch in length, and leaf-like, as in the Madagascar Langaha. The well-defined family of Lycodontidse is chiefly com- Lyco- posed of ground snakes, but a few of its members have a dontid& sufficiently elongate body to indicate arboreal habits. The Indian genera are principally reptilivorous, while the African prey upon mice, rats, and other small nocturnal mammals. Scarcely any other snake is so common in collections as the Indian Lycodon aulicus, which inhabits the continent of India and Ceylon, some of the islands of the East Indian Archipelago (Timor), and the Philippines. It occurs in many varieties, but generally is of a uniform brown, or with some whitish crossbands on the anterior part of the body. Although only 2 feet long, it is a fierce snake, which when surprised bites readily, but its bite is innocuous. The Boidee are so similar in their habits to the Pythons Boaa (see PYTHON, vol. xx. p. 144) that it is sufficient to refer in a few words to the species most frequently mentioned in the literature dealing with the fauna of the virgin forests of tropical America. The real Boa constrictor is com- mon from the north- ern parts of Central America to southern Brazil, and is fre- quently brought alive to Europe. Generally it is only about 7 feet long; but the present writer has seen skins of specimens which must have been nearly twice that length. The gigantic snakes of from 20 to 30 feet in length mentioned in books of South- American travels belong to a different species, the Anaconda or B. murina, which has the same habits as the B. constrictor, haunting the banks of rivers and lakes and lying in wait for peccaries, deer, and other mammals of similar size, which come to the water to drink. It has already been stated (see REPTILES) that this family is not restricted to South America, but is well represented in the tropical Pacific region. The Boid most common in that region is Enygrus, which ranges all over New Guinea, the Fiji Islands, the Solomon group, Samoa, and many other Pacific islands ; it is of small size, scarcely 30 inches long. We pass now to the Venomous Colubrine snakes, that is, snakes which combine with the possession of a perfect poison apparatus the scutellation and general appearance of the typical non-poisonous snakes. It is a remarkable FIG. 11. Head of Boa caniiut. FIG. 12. Head of Python retieulatus.