Page:Encyclopædia Britannica, Ninth Edition, v. 22.djvu/213

 SNAKES 197 Austral- No part of the world possesses so many snakes of this ian i>oi- su b-order as Australia, where, in fact, they replace the non- sonous venomous Colubrine snakes. Of the genus Diemenia six brine species, of Pseudechis three, and of Hoplocephalus some snakes, twenty species have been described, and many of them are extremely common and spread over a considerable area. FIG. 14. A jioisouous snake (Elaps fulmta) swallowing a DOB-poiBOnoQfl (Homalocntnium se m id net it m ). 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, especially if the simple measures of sucking or cauterizing the wound are resorted to. Only the following are dangerous to man and larger animals : the Brown Snake (Diemenia superciliosa), found all over Australia and attaining to a length of over 5 feet; the Black Snake (Pseudechis porphyriacu& likewise common throughout the Australian continent, especially in low marshy places, and upwards of 6 feet 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 Brown-banded Snake (Hoplo- cep/ialus ciirtus), with a similar distribution, and also com- mon in Tasmania, from 5 to 6 feet long, and considered the most dangerous of the tribe. 1 African The small family Causidx contains two African genera Causidiv. W ell known to and much feared by the inhabitants of South Africa. One, Sepedon haemachates, is named by the Boers "roode koper kapel" or " Ring -isTeck Snake," 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 courageous, 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 feet. The second African snake of this family is the " schapsticker " (Sheep Stinger), Causus rhombeatus. It is extremely common in South Africa and extends far north- wards along the eastern as well as western coast. It is of smaller size than the preceding and causes more injury to animals, such as sheep, dogs, tc., than to man. It varies in colour, but a black mark on the head like an inverted V remains nearly always visible. 1 Good descriptions and figures of all these snakes are given in Krefft's Snakes of Australia, Sydney, 1869, 4to. The Dinophidx are the arboreal type of this sub-order ; Dino- they resemble non-venomous tree snakes in their gracile-P*'^*- form, narrow scales, generally green coloration, and in their habits ; nevertheless the perfect development of their poison-apparatus, their wide mouth, their large size (they grow to a length of 7 feet), leave no doubt that they are most dangerous snakes. They do not appear to be com- mon, but are spread over all districts of tropical Africa in which vegetation flourishes. Of Sea Sn&].es>(Hydrophide) some fifty species are known. Sea All are inhabitants of the tropical Indo-Pacific ocean, and snakes, most numerous in and about the Persian Gulf, in the East Indian Archipelago, and in the seas between southern China and northern Australia. One species which is ex- tremely common (Pelamis licolor), and which is easily re- cognized by the black colour of its upper and the yellowish tints of its lower parts (both colours being sharply defined), has extended its range westwards to the sea round Madagascar, and eastwards to the Gulf of Panama. Sea snakes are viviparous and pass their whole life in the water; they soon die when brought on shore. The most striking feature in their organization is their ele- vated and compressed tail. The hind part of the body is compressed, and the belly forms a more or less sharp ridge. The ventral shields would be of no use to snakes moving through a fluid, and there- fore they are either only rudimentary or entirely absent. The genus Platurus, how- ever, is a most remarkable exception in having broad ventral shields ; probably these serpents frequently go on shore, sporting or hunting over marshy ground. In many sea snakes the hind part of the body is curved and prehensile, so that they are able to secure a hold by twisting this part of the body round corals, sea- weed, or any other projecting object. Their tail answers all the purposes of the same organ in fish, and their motions iu tin- water are almost as rapid as they are un- certain and awkward when the animals are removed out of their proper element. Their nostrils are placed quite at the top FlG. i5._sea"siiake, of the snout, as in crocodiles and in fresh- Peiamis Umior. water snakes, so that they are enabled to breathe whilst the entire body and the greater part of the head are immersed in the water. These openings are small and subcrescentic, and are provided with a valve interiorly, which is opened during respiration, and closed Avhen the animal dives. They have very capacious lungs, extending backwards to the anus, and consequently all their ribs are employed in performing the respiratory function ; by retaining air in these extensive lungs they are able to float on the surface of the water without the slightest effort, and to remain under water for a considerable length of time. The scales of sea snakes are frequently very different from those of other snakes : they overlap one another in only a few species ; in others they are but little imbricate and are rounded behind ; and in others they are of a subquadrangular or hexagonal form, placed side by side, like little shields. The less imbricate they are the more they have lost the polished surface which we find in other snakes, and are soft, tubercular, sometimes porous. Sea snakes shed their skin very frequently ; but it peels off in pieces as in lizards, and not as in the fresh- water snakes, in which the integiiments come off entire. Several species are remarkable for the extremely slender