[Illustration: _Photo by W. Saville-Kent, F.Z.S._] [_Milford-on-Sea._
Sea-snakes have compressed tails, which they use for steering.]
The typical TREE-SNAKES of the Indian and Australian region, with large eyes, somewhat compressed bodies, and colours of green or olive, in harmonious accord with their arboreal surroundings, also belong to the solid-toothed and harmless section. An especially interesting representative of this group is the so-called EGG-EATING SNAKE of South Africa. It does not exceed 2 feet in length, and is for the most part arboreal in its habits, and, as its name implies, would appear to feed exclusively on eggs. As a structural adaptation for this peculiar habit, the spinous processes of a number of the vertebræ project into the throat and are tipped with enamel, thus constituting supplementary throat-teeth. Normally this snake subsists on the eggs of the smaller birds, but when short of this supply has been known to leave the trees and rob hen-roosts, being able, notwithstanding its comparatively small size, to dilate its mouth and throat for the reception of a hen's egg. The egg is split longitudinally by the action of the throat-teeth, the contents swallowed, and the shell ejected.
The second or "back-fanged" group includes many exceedingly poisonous species. Among these may be mentioned the INDIAN WHIP-SNAKES and their allies, comprising many tree-frequenting species, closely resembling in habits and colours the harmless solid-toothed tree-snakes of the preceding section.
[Illustration: Photo by H. G. F. Spurrell, Esq.] [Eastbourne.
It is among the third or "front-fanged" group, however, that the most venomous species occur. To this section belongs the death-dealing COBRA, the yet more formidable HAMADRYAD, the INDIAN CRAITS, the EGYPTIAN ASP, and the AUSTRALIAN BLACK SNAKES and DEATH-ADDERS. The COBRA-DE-CAPELLO, HOODED, or SPECTACLED SNAKE, as it is variously known, is perhaps the most notoriously familiar example of its section, being responsible for the greater moiety of the many thousands of fatalities that annually occur among the natives of India from the bites of venomous serpents. The craits, which resemble the cobras, but do not possess an erectile hood, are accredited a second position in death-dealing. The peculiar feature of the erectile hood that characterises the cobras is due to the circumstance that a certain number of the ribs in this region are independently movable, and can be elevated and depressed at will, the skin-fold that overlies them being loose and elastic. The back of the hood in the ordinary Indian cobra is usually ornamented with two eye-like spots, connected with a loop-like band, which communicate to the complete pattern the fancied resemblance to a pair of spectacles, whence it has derived its appellation of Spectacled Snake. Individuals vary, however, very considerably in this matter of colour-markings; in some instances a single eye-like spot is alone developed, while in others it may be entirely absent. The COMMON COBRA grows to a length of 6 or 7 feet, dimensions greatly exceeded by the GIANT COBRA, or HAMADRYAD, a fortunately rarer form more exclusively confined to jungle and forest districts. This species may attain to a length of 13 feet or more, and on account of its deadly bite and fiercely aggressive disposition is much feared by the natives of the countries it inhabits, which include not only India, but Burma, Siam, and the Malay region. This giant cobra preys almost exclusively on smaller snakes, frequently including the common cobra.