Page:Encyclopædia Britannica, Ninth Edition, v. 22.djvu/214

 198 SNAKES and prolonged anterior part of the body, which is termed the " neck," and terminates in a very small head. The eye is small, with round pupil, which is so much con- tracted by the light when the snake is taken out of the water that the animal becomes blinded and is unable to hit any object it attempts to strike. The tongue is short, and the sheath in which it lies concealed opens near to the front margin of the lower jaw; scarcely more than the two terminating points are exserted from the mouth when the animal is in the water. The mouth shuts in a somewhat different way from that of other snakes: the middle of the rostral shield is produced down- wards into a small lobule, which prevents the water from entering the mouth ; there is generally a small notch on each side of the lobule for the passage of the two points of the tongue. Cantor says that when the snake is out of the water and FIG. 16. Rattlesnake (Crotalus din-issiis). blinded by the light it freely makes use of its tongue as a feeler. The food of sea snakes consists entirely of small fish ; the present writer has found all kinds of fish in their stomach, among them species with very strong spines (Apogon, Siluroids). As all these animals are killed by the poison of the snake before they are swallowed, and as their muscles are perfectly relaxed, their armature is harmless to the snake, which commences to swallow its prey from the head, and depresses the spines as deglutition proceeds. There cannot be the slightest doubt that sea snakes be- long to the most poisonous species of the whole order. Russell and Cantor have ascertained it by direct observa- tion : tortoises, other snakes, and fish died from their bite in less than an hour, and a man succumbed after four hours. Accidents are rarely caused by them, because they are extremely shy and swim away on the least alarm ; but, when surprised in the submarine cavities forming their natural retreats, they will, like any other poisonous terres- trial snake, dart at the disturbing object ; and, when out of the water, they attempt to bite every object near them, even turning round to wound their own bodies (Cantor). They cannot endure captivity, dying in the course of two or three days, even when kept in capacious tanks. The greatest size to which some species attain, according to positive observation, is about 12 feet, and therefore far short of the statements as to the length of the so-called sea serpents (see SEA-SERPENT). The largest examples the present writer has seen measured only 8 feet. Passing over Rattlesnakes (fig. 16) and Vipers, which are treated of in separate articles, we notice the following types of the fourth sub-order, the Ophidii viperiformes. The sole representative of the sub-order in Australia is Death the Death Adder (Acanthophis antarctica), a short stout adder of snake having a similar habitus and habits to vipers and scarcely attaining 3 feet in length. It differs from the Flo. 17. Echis carinata (India). other Viperines in having the poison-fang permanently erect. Although much feared, and justly, there is reason to believe that its bite is not so dangerous as has been represented, and that the majority of the fatal accidents ascribed to it are in fact caused by other snakes, probably Hoplocephalus curtus. It occurs throughout the whole of Australia, except Tasmania and perhaps South Australia. Generally it is of a uniform grey colour, relieved by some forty dark rings of irregular outline. The " tic-polonga " of the Singalese (Daboia russellii] Daboia is beautifully marked : on a light chocolate ground colour russeUii ' three series of large black white-edged rings run along the back and sides of the body, a yellow line borders the surface of the head on each side, the two lines being con- vergent on the snout. It attains to a length of 50 inches, and occurs locally in abundance in southern India, where it is called " cobra monil " ; in Bengal, where it is called "jessur"; in the plains of central India, as well as in the Himalayas to an altitude of 6000 feet ; and in Burmah. It is highly poisonous, probably causing many deaths.