Fig. 16.—Anaconda (Eunectes murinus).
The following description of the actions of one of these large non-venemous Serpents, which accompanied a specimen sent to the United Service Museum, by Sir Robert Ker Porter, is probably a fair description of the habits of all the large Pythonidæ:—"This species is not venemous, nor is it known to injure man (at least not in this part of the New World); however, the natives of the plain stand in great fear of it, never bathing in waters where it is known to exist. Its common haunt, or rather domicile, is invariably near lakes, swamps, and rivers; likewise close and wet ravines produced by inundations of the periodical rains. Fishes, as well as other animals which repair there to drink, are its prey. The creature lurks watchfully under cover of the water, and, while the unsuspecting animal is drinking, suddenly makes a dash at its nose, and with a grip of its back-reclining range of teeth, never fails to secure the terrified beast beyond the power of escape. In an instant the sluggish waters are in turbulence and foam. The whole form of the Serpent is in motion; its huge and rapid coilings soon encircle the struggling victim, and but a short interval elapses ere every bone in the body of the expiring prey is broken." Sir Robert then describes the manner in which the prey is swallowed, being previously lubricated by the Serpent's saliva; but Professor T. Bell, after carefully watching the constricting Serpent's mode of swallowing its prey, asserts that this is a delusion. "The mucus is not poured out till it is required to lubricate the dilated jaws and throat for the seemingly disproportionate feat."
[The small, but very distinct family of Erycidæ have the body of moderate length, cylindrical, covered with small and short scales; the tail very short, with only a single series of subcaudal scales; head somewhat elongate; eye rather small, with vertical pupil. Adult individuals have, like the Pythons, a short conical prominence in a groove on each side of the vent; this being the extremity of a rudimentary hind limb. "The Snakes of this family," remarks Dr. Günther, "shew great similarity to the Pythons and Boas, with regard to their internal structure as well as to their external characters. But their tail is very short, not flexible, and much less prehensile; and whilst the Serpents just mentioned are more or less arboreal, frequenting marshy places with luxuriant vegetation, the Erycidæ inhabit dry, sandy, or stony plains, burrowing with the greatest facility below the surface, and entering crevices and holes in search of their prey, which consists of Mice, Lizards, and other burrowing Snakes. Probably they are semi-nocturnal, and able to see in dark places as well as in the night. They are found in Northern Africa, in the islands of the Mediterranean, in the arid parts of India, and probably in Arabia; two species are known to have been brought from Sikhim."
The Cursoria elegans is said to be from Afghanistan; Eryx iacalus inhabits Greece and Egypt; and there is also E. thebaicus in the latter country, and E. Johnii in India. Another Indian species is the Gongylophis conicus, which the natives erroneously persist in declaring to be venemous. The Eryx Johnii is frequently found in the possession of the serpent-charmers of its native country, who mutilate the end of its short, thick tail in such a manner that the scarred extremity somewhat resembles the form of the head. Such specimens are shewn as deadly Two-headed Snakes, and, as such, are occasionally brought alive to Europe. An example of this species lived in the London Zoological Gardens for about eight years, and fed regularly on young Mice. The keeper assured Dr. Günther that it frequently covered its prey with saliva. It always kept itself hidden below the gravel at the bottom of its cage. This species attains to a length of nearly four feet, the tail measuring but four inches.
The Acrochordidæ constitute a very remarkable small family, of which one genus is terrene, and another highly aquatic in its habits. Whether a third genus, the Javanese Xenodermus, should be referred to it, is doubtful in the opinion of Dr. Günther. These Snakes have the body of moderate length, rounded, or slightly compressed, and covered with small wart-like, not imbricate, tubercular or spiny scales; tail rather short, prehensile; head rather small, not distinctly separated from the neck, and covered with scales like those of the body; nostrils close together, at the top of the snout; teeth short, but strong, of nearly equal size, and situate both in the jaws and on the palate. These serpents are viviparous. One of them, Acrochordus javanicus, inhabits Java and the Malayan peninsula, where it is considered rare. It grows to a length of eight feet, and its habits are terrene. The late Dr. Cantor justly compares its physiognomy to that of a thorough-bred bull-dog; a female in his possession brought forth no fewer than twenty-seven young in the course of about twenty-five minutes; they were active, and bit fiercely. Hornstedt found a quantity of undigested fruits in the stomach of this Serpent! Upon which Dr. Günther remarks that no opportunity of making further observations on the habits of this remarkable Snake should be lost. The aquatic member of this family, Chersydrus granulatus, inhabits from the coasts of India to those of New Guinea and the Philippine Islands. Sometimes it is met with at a distance of three or four miles from the shore. Mr. W. Theobald remarks that it is plentiful in the Bassein River (in British Burmah), in salt water below Gnaputau, and, with various other Sea Snakes, is frequently swept by the tide into the fishing baskets of the natives. The ebb-tide, running like a sluice, sweeps various Fishes, Crustaceans, Snakes, and even Porpoises occasionally, into the broad mouths of those baskets, where they are at once jammed into a mass at the narrow end of the creel. "The Chersydrus," he adds, "is more nearly connected with the Hydrophidæ than with the next family, being as essentially aquatic as any of the former, to which, save from its wanting the poison-gland, it might be appropriately referred. Indeed, it has been erroneously asserted by some authors to be venemous."
The Homalopsidæ are an extensive family of Snakes, of thoroughly aquatic habits, which are only occasionally found on the margins of rivers; several of them enter the sea, and in some parts of their organization they approximate to the true marine Snakes. They may be easily recognised by the position of the nostrils on the top of the snout, which enables them to breathe by raising only a very small portion of the head out of the water; an arrangement which is likewise seen in the Hippopotamus, the Crocodile, the Sea Snakes, and other aquatic animals. Many of them have a distinctly prehensile tail, by means of which they hold on to projecting objects. Their food consists either entirely of Fishes, or, in some species, of Crustaceans also. All appear to be viviparous, and the act of parturition is performed in the water. Not any of them attain a large size-about three or four feet in length, or considerably less; and in captivity they refuse to feed. All the Asiatic species of this family have a grooved fang at the hinder extremity of the maxillary bone. The species are numerous, and are arranged into many generic divisions. The majority are from the grand Indian region, extending to China and to Australia, but there are also several from the New World. The Herpeton tentaculatum, of Siam, is very remarkable from its snout terminating in two flexible, cylindrical, scaly tubercles, which are supposed to be employed as organs of touch under water—perhaps to discern its food, which as yet has not been ascertained. The largest known example of this curious Snake is only twenty-five inches long, of which the tail measures six inches.
We now proceed to the first family of Poisonous Snakes, that of
The Sea Snakes (Hydrophidæ),
Which are very distinct from all that follow, though less so from certain of the harmless species appertaining to the two families last treated of. Some of their distinctions have been already noticed (p. 45), but they are especially characterised by their highly compressed tail, indicative of their thoroughly aquatic habits. According to Dr. Günther, there is no other group of Reptiles the species of which are so little known, and the synonymy of which is so much confused, as that of the Sea Snakes. Most naturalists who have worked at them have been misled by the idea that the species were not nearly so numerous as they actually are. Mr. W. Theobald makes out as many as twenty-five inhabiting the Bay of Bengal and the adjacent seas, to which area this group of Reptiles is mainly confined, a few species extending to northern Australia, and one, the most emphatically pelagic, the Pelamis bicolor, even to the Pacific Ocean. One genus only, Platurus, approaches the Land Snakes in several of its characters; having much the physiognomy of an Elaps, with the cleft of the mouth not turned upwards behind, as in other Sea Snakes; the eye also is rather small, nor is the tail at all prehensile. There are two species of this particular form, one of which, P. scutatus, is rather common, and its geographic range extends from the Bay of Bengal and the China seas to the coasts of New Zealand; the distribution of the other, P. Fischeri, being nearly as extensive. The great genus Hydrophis has the posterior part of the body highly compressed, and most of the species are more or less of a bluish lead-colour, like that of the sea, or black, banded with white or yellowish white. They are so abundant in the Indian seas that some of them are taken with every haul of a fishing-net, and they are helpless and seemingly blind when out of the water; the fishermen commonly seizing them, one after the other, by the nape and throwing them back into the sea. Some of them (Microcephalophis of Lesson) have the head very small and the neck exceedingly slender, while the compressed body is large and thick.