Page:EB1911 - Volume 25.djvu/307

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291
SNAKES


teeth, hence the terra " proteroglypha," which is intended to mean that the anterior teeth are grooved. These snakes are ail very poisonous, mostly viviparous and found in all tropical and sub- tropical countries, with the exception of Madagascar and New Zealand.

Sub-family 1. Elapinae. — Terrestrial, with a cylindrical tail, comprising about 150 species which have been grouped into numerous genera, mostly upon very slight differences. The most remarkable are the following. Naja tripudians and N. haje, the cobra (q.v.). The largest species is the N. bungarus s. elaps, the " hamadryad," " snake-eating cobra," or king-cobra of Indian countries, reaching more than 12 ft. in length, and living mainly upon other snakes. Sepedon haemackates, of S. Africa, is named by the Boers " roode

Fig. 8. — Indian Whip-Snake. Passerita mycterizans.

koper kapel" or " ring-hals," i.e. banded neck, the latter name being, however, often applied also to the cobra. It resembles in colour some varieties of the latter snake, and, like this, it has the power, though in a less degree, of expanding its hood. But its scales are keeled and its form is more robust. It is equally active and courage- ous, not rarely attacking persons who approach too near to its resting-place. In confinement it evinces great ferocity, opening. its mouth and erecting its fangs, from which the poison is seen to flow in drops. During such periods of excitement it is even able, by the pressure of the muscles on the poison-duct, to eject the fluid to some distance; hence it shares with the cobra a third Dutch name, that of " spuw slang " (spitting snake). It grows to a length of 2 or 3 ft. Another kind is the " schapsticker " (sheep stinger), 5. rhombeatus. It is extremely common in S. Africa, and extends far N. along the

Fig. 9. — Head of Herpeton tentaculatum.

E. as well as W. coast. It is of smaller size than the preceding, and causes more injury to animals, such as sheep, dogs, &c. than to man. It varies in colour, but a black mark on the head like an inverted V remains nearly always visible.

The species of Bungarus, four in number, are extremely common in India, Burma, and Ceylon, and are distinguished by having only one row of undivided sub-caudal shields. Three of the species have the body ornamented with black rings, but the fourth and most common (B. coeruleus), the " krait" of Bengal, possesses a dull and more uniform colora- tion. The fangs of the bunga- rums are shorter than those of the cobras, and cannot penetrate so deeply into the wound. Their bite is therefore less dangerous and the effect on the general system slower, so that there is more prospect of recovery by treatment. Nevertheless, the krait is probably the most destructive snake to human life in India, since it is very common and often creeps into the houses. Doliophis intestinalis of Indo-China has enormously developed poison glands, which extend down the whole anterior third of the body, in front of the heart.

No part of the world possesses so many snakes of this sub-family as Australia, where, in fact, they replace the non-venomous colubrine snakes; many of them are extremely common and spread over a considerable area. Fortunately the majority are of small size, and their bites are not followed by more severe effects than those from the sting of a hornet. Only the following are dangerous to man and larger animals: the " death-adder," Acanthosis antarctieus, easily recognized by the peculiar end of the tail which is compressed and terminates in a thin horny spine; common throughout Australia to the Moluccas, scarcely one yard in length; the " black snake " (Pseudechis porphyriacus) , likewise common throughout the Australian continent, especially in low marshy places, and upwards of 6 ft. in length; it is black, with each scale of the outer series red at the base; when irritated it raises the fore part of its body and flattens out its neck like a cobra, the females are sometimes known as "brown adders"; the "tiger-snake," Nolechis scutatus (s. Hoplocephalus curtus), with a similar distribution, and also common in Tasmania, from 5 to 6 ft. long, and considered the most dangerous of the tribe. Good descriptions and figures of all these snakes are given in Krefft's Snakes of Australia (Sydney, 1869, 4to).

Several genera of the Elapinae lead a more or less burrowing life ; their body is of a uniform cylindrical shape, terminating in a short tail, and covered with short polished scales; their head is short, the mouth rather narrow, and the eye small. They are the tropical American Elaps, the Indian Callophis, the African Poecilophis and the Australian Vermicella. The majority are distinguished by the beautiful arrangement of their bright and highly ornamental colours ; many species of Elaps have the pattern of the so-called coral-snakes, their body being encircled by black, red and yellow rings — a pattern

Fig. 10.— A Poisonous Snake {Elaps fulvius) swallowing a similarly coloured Opisthoglyphous Snake (Homalocranium semicinctum).

which is peculiar to snakes, venomous as well as non-venomous, of the fauna of tropical America. Although the poison of these narrow-mouthed snakes is probably as virulent as that of the preceding, man has much less to fear from them, as they bite only under great provocation. Moreover, their bite must be frequently without serious effect, owing to their narrow mouth and the small size of their poison-fangs. They are also comparatively of small size, only a few species rarely exceeding a length of 3 ft., for instance Elaps futvius, which extends into the S. states of N. America.