II.—General Classification of Poisonous Snakes. Their Anatomo-physiological Characters.
Poisonous snakes are divided by naturalists into two great Families, the Colubridæ and Viperidæ, distinguished from each other by certain anatomical characters, and especially by the dentition.
The Colubridæ resemble harmless snakes, which renders them all the more dangerous.
They are divided into two groups: Opisthoglypha (ὄπισθεν, behind; γλυφὴ, a groove) and Proteroglypha (πρότερον, before; γλυφὴ, a groove).
The Opisthoglypha have the upper jaws furnished in front with smooth or non-grooved teeth, but behind with one or several rows of long, canaliculate teeth.
This group includes three Sub-families:—
A. The Homalopsinæ, having valved nostrils, placed above the snout.
B. The Dipsadomorphinæ, in which the nostrils are lateral in position, and the dentition is highly developed.
C. The Elachistodontinæ, which have but rudimentary teeth only on the posterior portion of the maxillary, on the palatine and on the pterygoid bones.
Almost all the snakes belonging to these three sub-families are poisonous, but only slightly so. They are not dangerous to man. Their venom merely serves to paralyse their prey before deglutition takes place; it does not afford them an effective means of defence or attack.
All the Homalopsinæ are aquatic; they bring forth their young in the water, and are met with commonly in the Indian Ocean, starting from Bombay, and especially in the Bay of Bengal, on the shores of Indo-China and Southern China, from Singapore to Formosa, in the Dutch Indies, in Borneo, the Philippines, New Guinea and the Papuan Archipelago, and as far as the north of Australia.
The Dipsadomorphinæ comprise a large number of highly cosmopolitan genera and species, found in all the regions of the earth except the northerly portions of the Northern Hemisphere. None of these reptiles is capable of causing serious casualties among human beings, owing to the peculiarly defective arrangement of their poison-apparatus. I therefore do not think it worth while to linger here over their description.
The Elachistodontinæ are of even less importance; at the present time only two species are known, both of small size and confined to Bengal.
The Proteroglypha group of the Colubridæ is of much greater interest to us, since all the snakes belonging to it are armed with powerful fangs, in front of the upper maxillaries. These fangs, which are provided with a channel in the shape of a deep groove, communicate at the base with the efferent duct of poison glands, which are often of very large size.
The group is composed of two Sub-families:—
A. The Hydrophiinæ (sea-snakes), provided with a flattened oar-shaped tail. The body is more or less laterally compressed; the eyes are usually small, with circular pupils; the scales of the nose have two notches on the upper labial border.
The normal habitat of all the members of this sub-family is the sea, near the shore, with the exception of the genus Distira, which is met with in the fresh water of a lake in the Island of Luzon, in the Philippines. They are frequently found in very large numbers in the Indian seas and throughout the tropical zone of the Pacific Ocean, from the Persian Gulf to the west coast of the American Continent, but they are entirely absent from the West Coast of Africa.
B. The Elapinæ (land-snakes), with a cylindrical tail, and covered with smooth or carinate scales. These serpents are frequently adorned with brilliant colours. Some of them (belonging to the genus Naja) have the faculty of expanding the neck in the shape of a parachute, by spreading out the first pairs of ribs when they are alarmed or excited: the breadth of the neck then greatly exceeds that of the head. They are distributed throughout Africa, Asia, and North and South America, and are also found in Australia, where almost all the snakes that are known belong to this sub-family.
The Family Viperidæ is characterised by a triangular head, which is widened posteriorly, and by the general aspect of the body, which is usually thick-set and terminated by a short tail. The bones of the face are movable. The præfrontal bone is not in contact with the nasal; the maxillary is greatly shortened and may be articulated perpendicularly to the ectopterygoid; it bears a pair of large poison-fangs, one on each side, and these are always accompanied by several teeth to replace them, folded back in the gum; these latter teeth come in succession to take the place of the principal tooth, when this is broken or falls out of itself when the snake sheds its skin.
The poison-fangs are not grooved, as in the Proteroglyphous Colubridæ; they are pierced by a perfectly formed canal, the upper end of which inosculates with the efferent duct of the corresponding poison-gland, while its lower extremity opens to the exterior a little above and in front of the tip. The latter is always very sharp.
The palate and lower jaw are furnished with small hooked teeth, which are solid and non-venomous.
With the exception of the species of Atractaspis, these snakes are all ovoviviparous. The majority are terrestrial; a few lead a semi-aquatic existence, while others are arboreal.
Their distribution includes Europe, Asia, Africa (with the exception of Madagascar), and North and South America. They do not exist in Australia.
They are divided into two Sub-families:—
A. The Viperinæ, in which the head, which is very broad and covered with little plates and scales, has no pit between the nose and the eyes;
B. The Crotalinæ (κρὁταλον, a rattle), in which the head is incompletely covered with scales, and exhibits a deep pit on each side, between the eye and the nostril.
Among snakes, the characters that serve as a basis for the determination of genera and species are the general shape of the body, especially that of the head, the arrangement of the cephalic scales, the cranial skeleton, and the dentition.
Cranial Skeleton.—The cranium is composed of a certain number of bones, the homologues of which are found in the mammalian skeleton; but the bones are complex, and subject to modifications according to the structure and habitat of each species.
The special arrangement of the bones of the face is above all characteristic of the poisonous snakes. Those forming the upper jaw, the palate and the mandibles or “inter-maxillaries” are movable upon each other and on the cranium. The upper and lower maxillaries are united by an extensile ligament and articulated with the tympanic bone, which permits the mouth to be opened very widely when the animal swallows its prey.
Dentition.—The non-poisonous snakes have two rows of teeth in the upper jaw—one external, the maxillary, usually composed of from 35-40 small, backwardly curved teeth; the other internal, the palatine, which only numbers from 20-22 teeth, having the same curvature ([fig. 1], A).
Fig. 1.—A, Cranial skeleton of one of the non-poisonous Colubridæ (Ptyas mucosus); B, cranial skeleton of one of the poisonous Colubridæ (Naja tripudians); C, cranial skeleton of one of the poisonous Colubridæ (Bungarus fasciatus); D, cranial skeleton of one of the Viperidæ (Vipera russellii); E, cranial skeleton of one of the Viperidæ Crotalinæ (Crotalus durissus); F, cranial skeleton of one of the Colubridæ Hydrophiinæ (Hydrophis pelamis).
In the poisonous snakes the maxillary bones are shorter, and the outer row is represented by a single long and tubular or grooved tooth (the fang), fused with the maxillary bone, which is itself movable ([fig. 1], B, C, D, E, F).
Fig. 2.—A, Maxillary bone and fangs of one of the Viperidæ (Vipera russellii); B, maxillary bone and fangs of one of the Colubridæ (Naja tripudians); C, maxillary bone and fangs of one of the Colubridæ (Bungarus fasciatus); D, maxillary bone and teeth of one of the non-poisonous Colubridæ (Ptyas mucosus). (After Sir Joseph Fayrer.)
Certain species (Dipsas) have maxillary teeth which increase in size from front to rear; the longest teeth are grooved and serve for the better retention of prey, and also to impregnate it with saliva; but they are not in communication with the poison-glands.
The poison-fangs are normally covered with a fold or capsule of mucous membrane, in which they are sheathed. This fold conceals a whole series of reserve teeth in different degrees of development, which eventually become attached to the extremity of the maxillary when the principal tooth falls out or is broken ([fig. 2]).
Fig. 3.—A, Fang of one of the Viperidæ (Vipera russellii); D, transverse section of the fang.
Poison Apparatus.—The grooved or furrowed teeth in the Proteroglypha and the canaliculate teeth in the Solenoglypha are arranged, not for the purpose of seizing prey, but in order to deal it a mortal blow by injecting the venom into its flesh.
In the normal position they lie almost horizontally, and exhibit no mobility of their own. But, when the animal prepares to bite, their erection is effected by the snake throwing its jaw back; and this movement, which is always very sudden, enables it at the same time to compress its poison-glands, by the aid of special constrictor muscles.
On examining the various species of poisonous snakes, we observe very sharply marked differences in the arrangement and dimensions of the teeth. Thus, in the Viperidæ they are long, extraordinarily sharp, and capable of producing deep wounds ([fig. 2], A, and [fig. 3]). They are traversed by an almost completely closed canal, from the base, which communicates with the poison-duct, to the neighbourhood of the point, where it opens very obliquely on the convex surface ([fig. 3], A and D).
Fig. 4.—B, Fang of one of the Colubridæ (Naja tripudians); E, transverse section.
Fig. 5.—C, Fang of one of the Hydrophiinæ (Hydrophis pelamis); F, transverse section.
Fig. 6.—Three transverse sections of a poison-fang of one of the Colubridæ, through A A, B B, C C; P P, pulp cavity; V V V, poison-canal (groove). (After C. J. Martin.)
In the Elapinæ sub-family of the Colubridæ, and especially in the Hydrophiinæ, the teeth are much shorter and simply grooved or canaliculate; that is to say, the canal communicates with the exterior throughout its extent by a narrow slit, which traverses the entire convex surface of the tooth (figs. 4, 5, and 6).
It does not follow from this that the bites of these reptiles are less dangerous; the contrary, indeed, is the case, for their venom is infinitely more active.
These differences, as well as the particular mode of arrangement of the other little non-poisonous teeth in both jaws, enable us in many cases to recognise, by the mere appearance of the bite, the species of snake by which the bite has been inflicted.
Fig. 7.—Marks produced on the Skin by the Bites of different Species of Snakes.
I. Non-venomous Colubrine.—The bite is marked only by the imprint of from 35-40 small palatine or pterygoid teeth, and 20-22 upper maxillary teeth (on the outside of the foregoing) on each side.
II. Venomous Colubrine (Naja tripudians, Proteroglypha).—The bite exhibits 25 or 26 punctures from the pterygoid or palatine teeth, and, on each side, one or two, rarely three, circular wounds produced by the principal poison-fangs and by the reserve teeth.
III. Viperidæ (Solenoglypha).—The sole indication of the bite consists of 8 or 10 punctures from the palatine or pterygoid teeth, and one little round wound, on each side, produced by the poison-fangs.
(After Sir Joseph Fayrer.)
Fig. 7, above, shows how it is possible to distinguish the marks left by a non-venomous reptile, and by one of the Proteroglypha or Solenoglypha respectively.
Poison-glands.—The poison-glands occupy an extensive inter-muscular space behind the eyes, on each side of the upper jaw. They are oval in shape, and may, in Naja tripudians for example, attain the size of a large almond ([fig. 8]).
Their structure is the same as that of the salivary glands of the larger animals. The poison that they secrete accumulates in their acini and in the efferent duct that opens at the base of the corresponding fang.
Each gland is surrounded by a capsule, to which are partly attached the fibres of the masseter muscle, which violently compresses it and drives the poison, just as the piston of a syringe would do, into the canaliculi or groove of the fang.
Fig. 8.—Poison-gland and Fangs of a Venomous Snake (Naja tripudians, Colubridæ). (Natural size.)
L, Lobe of the gland; D, poison-duct; F, fang attached to the maxillary bone; G G, gland; M, capsule of mucous membrane surrounding the fangs; R, reserve fangs; A A, muscular fascia covering the gland.
(After Sir Joseph Fayrer.)
In a few venomous snakes the gland is developed to such an extent that it extends as far as the first ribs.
The species, on the contrary, that have the poison-teeth placed in the hinder part of the mouth (Opisthoglypha) have glands but little developed.
Muscular Apparatus of the Head.—Figs. 9 and 10, 11 and 12 show the arrangement of the principal muscles that work the jaws and glandular organs in Vipera russellii and Naja tripudians, which respectively represent the most formidable types of Viperidæ and venomous Colubridæ.
It is not necessary to give a detailed description of each of these muscles. Let it suffice to point out that all contribute in giving the greatest elasticity to the jaws, and at the same time strength sufficient to retain the prey and to cause it to pass from front to rear towards the œsophagus, by a series of alternate antero-posterior movements and analogous lateral ones. By means of these movements, which are participated in by the upper and lower maxillary bones, the palatines, mandibles or inter-maxillaries, and the pterygoids, the animal in a manner draws itself over its prey like a glove, since the arrangement of its dentition does not admit of mastication.
A A, Fascia covering the anterior and posterior temporal muscles; B, small gland; C, tendinous insertion of the fascia; D, poison-duct; E, poison-fang; F, reserve fangs; G, mandible; H, ectopterygoid muscle; J, poison-gland covered by the masseter; K, masseter inserted in the mandible; L, insertion of the temporal muscle; M, digastric muscle.
A A, Ectopterygoid muscle; B, præ-spheno-pterygoid muscle; C, intermandibular muscle; D, præ-spheno-palatine muscle; E præ-spheno-vomerine muscle; F, capsule of mucous membrane surrounding the fangs; G, long muscle of the neck.
Figs. 9 and 10.—Muscular Apparatus and Poison-gland of Vipera russellii
(Viperidæ). (After Sir Joseph Fayrer.)
A, Tracheo·mastoid muscle; B B, digastric muscle; C C, posterior temporal muscle; D D, anterior temporal muscle; E E, masseter; F, poison-gland, covered by the masseter and fascia; G, poison-duct; H, maxillary bone; I, neuro-mandibular muscle; J, costo-mandibular muscle.
A, Entopterygoid muscle; B, poison-gland; C, poison-duct; D, poison-fangs; E, præ-spheno-palatine muscle; F, præ-spheno-vomerine muscle; G, capsule of mucous membrane surrounding the fangs; H, præ-spheno-pterygoid muscle (which erects the fangs); J, inter-mandibular muscle; K, ectopterygoid muscle; L, long muscle of the neck (longus colli).
Figs. 11 and 12.—Muscular Apparatus and Poison-gland of Naja tripudians
(Colubridæ). (After Sir Joseph Fayrer.)
Fig. 13.—Arrangement of the Scales of the Head in one of the Non-poisonous Colubridæ (Ptyas mucosus). (After Sir Joseph Fayrer.)
A, Rostral scale; B, anterior frontals; B1, posterior frontals; C, vertical; D, occipitals; E, supra-ciliaries; F, temporals; L, M, nasals; N, loreals, or frenals; O, anterior oculars, or præ-orbitals; P, posterior oculars, or post-orbitals; Q, supralabials; G, median infralabial; H H, lateral infralabials; I K, mentals.
The enormous extensile power of the mouth and œsophagus thus enables snakes to swallow animals, the size of which is several times in excess of their own diameter.
Deglutition is slow and painful, but the gastric and intestinal juices are so speedy in action, that the digestion of the most resistant substances rapidly takes place. The very bones are dissolved, and the fæces, which are voided some days later, contain only a few osseous remains and a felt-like material composed of hair or feathers.
Scales.—The skin of snakes, which is very elastic and extensile, is covered with scales, small on the back, and in great transverse plates on the entire ventral surface.
Fig. 14.—Arrangement of the Scales of the Head in one of the Poisonous Colubridæ (Naja tripudians, OR Cobra-di-Capello). (After Sir Joseph Fayrer.)
The shape and dimensions of the scales of the head are highly characteristic in each species. It is therefore necessary to know their names and the arrangement that they exhibit: these details are shown with sufficient clearness in figs. 13 and 14.
Coloration.—The colouring exhibited by the scales of snakes is governed generally by the biological laws of mimicry. It is therefore not a character of specific value, and may be modified several times in the course of the existence of the same reptile, according to the surroundings in which it is obliged to live.
“Nature,” write Dumeril and Bibron, “seems to have caused the tints and colours of snakes to vary in accordance with their habits and modes of life. Generally speaking, the colours are greyish or dull in species that are wont to live among sand, or which bury themselves in loose earth, as also in those that lie in wait on the trunks or large boughs of trees; while these hues are of a bluish-green, resembling the tint of the leaves and young shoots of plants, in snakes that climb among bushes or balance themselves at the end of branches. It would be difficult to describe all the modifications revealed by a general study of the colours of their skins. Let us imagine all the effects of the decomposition of light, commencing with white and the purest black, and passing on to blue, yellow, and red; associating and mixing them together, and toning them down so as to produce all shades, such as those of green, of violet, with dull or brilliant tints more or less pronounced, and of iridescent or metallic reflections modified by spots, streaks, and straight, oblique, undulating, or transverse lines. Such is the range of colours to be found in the skin of snakes.”
This skin is covered by a thick epidermis, which is periodically detached in its entirety, most frequently in a single piece. Before effecting its moult, the reptile remains in a state of complete repose for several weeks, as if asleep, and does not eat. Its scales grow darker and its skin becomes wrinkled. Then one day its epidermis tears at the angle of the lips. The animal thereupon wakes up, rubs itself among stones or branches, divests itself entirely of its covering as though it were emerging from a sheath, and proceeds forthwith in quest of food.
The moult is repeated in this way three or four times every year.
CHAPTER II.
HABITS OF POISONOUS SNAKES. THEIR CAPTURE.
All poisonous snakes are carnivorous. They feed on small mammals (rats, mice), birds, batrachians, other reptiles or fish, which they kill by poisoning them by means of their fangs.
They almost always wait until their prey is dead before swallowing it.
Some of them are very fond of eggs, which they well know how to find in the nests of birds, and swallow whole.
When a poisonous snake wishes to seize its prey, or strike an enemy, it raises its head, and depresses the lower and elevates the upper jaw in such a way that the fangs are directed straight forward. Then, with the quickness of a spring when it is released, the reptile makes a sudden dart and strikes its victim. After inflicting the wound it draws back, doubles up its neck and head, and remains prepared to strike again.
So rapid is the action of the venom, that the wounded animal falls to the ground almost immediately; it is forthwith stricken with paralysis, and dies in a few moments. In most cases the snake holds it in its mouth until death ensues; the reptile then sets to work to swallow its victim, an operation which is always slow and painful.
In captivity poisonous snakes almost always refuse to take any food whatever. If it be desired to keep them for a long time, it is often necessary to resort to artificial feeding. For this purpose the snake is seized by the head by means of a strong pair of long forceps; it is then grasped by the neck with the left hand without squeezing too hard ([fig. 15]), taking care at the same time not to give the body a chance of coiling itself round anything. Next, one or more lumps of beef or horse-flesh are introduced into the jaws, and gently forced down deep into the œsophagus by means of a glass rod, which is polished in order not to injure the mucous membrane. The œsophagus is then gently massaged in a downward direction, in order to cause the bolus of food to descend into the stomach ([fig. 16]). This operation is repeated every fortnight.
Fig. 15.—Feeding a Poisonous Snake, First Stage.
Fig. 16.—Feeding a Poisonous Snake, Second Stage.
Fig. 17.—Catching a Cobra-di-Capello (Naja tripudians), First Stage. (At the French Settlement of Pondicherry, in India.)
In this way, at my laboratory, I have been able to preserve, in perfect condition for more than two years, Indian Cobras and Fers-de-lance from Martinique, taking care to keep them in a hothouse, at a temperature of about 82° to 86° F.
It is also very important to place inside the cases a vessel full of water, which should be frequently changed, for almost all snakes drink often and like to bathe for whole days at a time.
Fig. 18.—Catching a Cobra-di-Capello (Naja tripudians), Second Stage. (At the French Settlement of Pondicherry, in India.)
Within their reach should be placed in addition branches and rockwork, against which they rub at the moulting times, in order periodically to rid themselves of their scarf-skin.
While moulting, snakes must neither be touched nor fed, since to force them to take food at such a time would be fatal.
Snake-catching.—The capture of poisonous snakes, in order to keep them alive, can only be performed without danger by skilful persons, who are possessed of much coolness.
The best way of securing them is suddenly to pin the neck to the ground by means of a stick held horizontally, or a small two-pronged fork of wood or metal ([fig. 17]).
The stick is rolled along until close to the occiput ([fig. 18]). The animal can then be seized with the hand immediately behind the head, in such a way that it is impossible for it to turn and bite. It is then put into a wire cage, provided with a small movable trapdoor, with the fastening on the outside.
In this way poisonous snakes can be sent to a distance, and left without food for one or even two months, provided that they be kept in a place which is somewhat moist and sufficiently warm.
Fig. 19 shows how captured cobras are carried in India, in the environs of Pondicherry. They are enclosed in earthern chatties, or in baskets of plaited bamboo, which are provided with covers, and are very convenient for carrying snakes short distances.
Fig. 19.—Hindu carrying Two Captured Cobras in “Chatties.”
CHAPTER III.
DESCRIPTION OF THE PRINCIPAL SPECIES OF POISONOUS SNAKES. THEIR GEOGRAPHICAL DISTRIBUTION.
Poisonous snakes are especially common in the tropical zones of the Old and New Worlds. The species found in Europe are but of small size and not very formidable. In hot countries, on the other hand, they attain large dimensions, their venom is much more active, and, although they hardly ever attack man, and in most cases avoid him, they cause a considerable number of fatal accidents.
It is sometimes a rather difficult matter to recognise from the mere appearance of a snake whether it is poisonous or not. Naturalists themselves are occasionally deceived. It is therefore useful to learn to distinguish the most dangerous species by their external characters, and to know in what countries there is a risk of their being encountered.
A.—EUROPE.
Of the continents of the Old World, the poorest in poisonous snakes is Europe. The only species found there are a Cœlopeltis (belonging to the Sub-family Dipsadomorphinæ of the Opisthoglypha), and certain Viperinæ, which rarely exceed 75 centimetres in length.
Cœlopeltis, the cranial skeleton and head of which are represented in [fig. 20], is characterised by a narrow, concave frontal shield, projecting supraciliaries, short snout, large eyes, with round pupils, two poison-fangs at the back of the upper maxillaries, and a cylindrical body. The scales of the back are finely grooved, and in the adult slightly concave.
Fig. 20.—Maxillary, Mandible, and Head of Cœlopeltis monspessulana.
The coloration, olivaceous-brown, or deep red on the back, becomes on the ventral surface pale yellow with brown streaks, and from five to seven longitudinal series of small spots, which are blackish and edged with yellow on the sides.
The mean total length is 1,800 millimetres. The tail is somewhat tapering, and about 350 millimetres long.
The only European species is Cœlopeltis monspessulana, which is met with pretty commonly in France, in the neighbourhood of Montpellier, and Nice, near Valencia in Spain, and in Dalmatia. It is likewise found throughout North Africa, and in Asia Minor.
A second species, Cœlopeltis moilensis, occurs in Southern Tunis, Egypt, and Arabia.
The European Viperinæ belong exclusively to the Genus Vipera, the principal zoological characters of which are as follows:—
Head distinct from the neck, covered with small scales, with or without frontal and parietal shields; eyes small, with vertically elongate pupils, separated from the labials by scales; nostrils lateral. Body cylindrical. Scales keel-shaped, with an apical pit, in from 19-31 rows; ventral scales rounded. Tail short; subcaudal scales in two rows.
The Genus Vipera is represented in Europe by several species, which are likewise found in Western Asia and North Africa.
These species are:—
V. ursinii, V. berus, V. aspis, V. latastii, and V. ammodytes. [1]
Vipera ursinii.
Snout obtuse, soft on its upper surface, with the frontal and parietal shields distinct, the former about one and a half times as long as broad, and almost always longer than the parietals. A single series of scales between the eyes and the free margin of the lips.
Temporal shields smooth. Body scales in from 19 to 21 rows, strongly keeled on the back, less strongly on the sides.
Colour yellowish or pale brown above, grey or dark brown on the sides, sometimes uniform brown; spots more or less regular on the vertebral column, oval, elliptic or rhomboidal, dark brown or flecked with white, sometimes forming an undulous or zigzag band; two or three longitudinal series of dark brown or black spots on the sides; small dark dots running obliquely from the eye to the angle of the mouth; nose and lips white, and one or two dark angular streaks on the head; chin and throat yellowish; belly black, with transverse series of white or grey dots. No sexual differences in coloration.
Total length from 420-500 millimetres; tail 50-55.
Habitat: South-east France (Basses-Alpes); Italy (Abruzzi); Istria; Mountains of Bosnia; Plains of Lower Austria; Hungary (environs of Buda-Pesth).
Vipera berus (Common Viper, or Adder).
Snout rounded, short and truncate; pupil vertically elongate; vertical diameter of the eyes equal to or greater than the distance separating them from the mouth; frontal and parietal shields distinct, the former as long as broad, usually shorter than the space separating it from the rostral shield; 6-13 scales round the eyes; one or rarely two series of scales between the eyes and the lips; nasal shield single, separated from the rostral by a naso-rostral shield; temporal scales smooth. Body scales in 21 rows (exceptionally 19 or 23), strongly keeled; 132-150 ventral shields; 38-36 subcaudals.
Fig. 21.—(1) Vipera berus; (2) Vipera aspis; (3, 4) Vipera ammodytes.
(Natural size.)
Colour very variable, grey, yellowish, olive, brown, or red above, generally with an undulating or zigzag band along the vertebral column, and a series of lateral spots. A black spot shaped like a V, an X, or a circumflex accent, on the head. The tip of the tail is yellow or reddish. Some specimens are entirely black.
Total length from 350 to 700 millimetres; tail 75 to 90.
Habitat: Northern Europe, and especially the mountains of Central Europe; irregularly distributed in Southern Europe; Northern Spain and Portugal, Northern Italy, Bosnia, Caucasus.
This viper, which is very common in France, ranges as far as the Scandinavian Peninsula to about the 65th parallel of North Latitude. It is sometimes met with among the mountains at an altitude of about 6,500 feet (2,000 metres). It is found on heaths, in grass-lands, vineyards, and forests. Certain parts of the sandy moors of North Germany are literally infested with it. It abounds in the Jura, Isère, Ardèche, Auvergne, Brittany, Vendée, and the Forest of Fontainebleau.
It seeks its prey by night, and feeds on voles, small birds, frogs, lizards, and small fish. During the summer it shows a preference for moist places, often even remaining in the water, in which it swims with ease.
Light and fire attract it. It does not climb trees, but is frequently found coiled up on boughs of dead wood scattered on the ground.
When on the defensive, and preparing to bite, it throws its head back, and makes a sudden dart of from a foot to sixteen inches. If irritated it makes a sort of hissing noise.
To pass the winter it retires into the crevices of rocks or into old tree-trunks, where it entwines itself closely with a number of its congeners. In this way ten or fifteen vipers are frequently found together in the same hole.
In April, the whole company awakes, and copulation then takes place. The eggs are laid in August and September, and the young immediately crawl out of the shell, already prepared to bite, and capable of finding their own food. Their length at birth amounts to 230 millimetres.
The two glands of an adult adder contain about 10 centigrammes of poison. This small quantity is sometimes sufficient to cause death; out of 610 persons bitten, Rollinger returns 59 deaths, or about 10 per cent.
In the departments of Vendée and Loire-Inférieure alone, Viaud Grand Marais has noted during a period of six years 321 cases of bites from adders, 62 of which were followed by death. In Auvergne, Dr. Fredet[2] (of Royat) returns 14 cases, which caused 6 deaths.
Vipera aspis (Asp, or Red Viper).
([Fig. 21], 2, and [fig. 22].)
Snout slightly turned up, soft and squarely truncate; vertical diameter of the eyes equal to the space separating them from the mouth; upper surface of the head usually covered with small, imbricate, smooth or feebly keeled scales, in 4-7 series, between the supraocular shields, which are prominent. The frontal and parietal shields are usually wanting; sometimes they are distinct, but small and irregular; the former are separated from the supraoculars by two series of scales; 8-13 scales round the eyes; two (rarely three) series of scales between the eyes and the labials; nasal shield single, separated from the rostral by a naso-rostral shield. Body scales in 21-23 rows, strongly keeled; 134-158 ventrals; 32-49 subcaudals.
Coloration very variable, grey, yellowish, brown, or red above, with a zigzag band as in V. berus. Usually a black U-shaped mark on the hinder part of the head, with a longitudinal black streak behind the eyes; upper lip white, or yellowish. Ventral surface yellow, white, grey, or black, with lighter or darker markings.
Total length, 620-675 millimetres; tail 75-95.
Habitat: France (especially Vendée, the Forest of Fontainebleau, and the South), Pyrenees, Alsace-Lorraine, the Black Forest, Switzerland, Italy and Sicily, and the Tyrol.
This viper especially frequents dry, rocky, and arid hillsides, which are exposed to the sun. Like the adder, it hibernates in tree-trunks and old walls. It lays from 6 to 15 eggs, from which the living young immediately issue, provided with poison. It feeds upon small rodents, worms, insects, and young birds. Raptorial birds, storks, and hedgehogs pursue it and devour it in large numbers.
Fig. 22.—Vipera aspis. (Natural size.) (From the Forest of Fontainebleau.)
Vipera latastii.
Intermediate between V. aspis and V. ammodytes. Snout less turned up into a corneous appendage than in the latter. Head covered with small, smooth, or feebly keeled, subimbricate scales, among which an enlarged frontal shield may sometimes be distinguished; 5-7 longitudinal series of scales between the supraocular shields; 9-13 scales round the eyes; 2 or 3 series between the eyes and the labials; nasal shield entire, separated from the rostral by a naso-rostral. Body scales in 21 rows, strongly keeled; 125-147 ventrals; 32-43 subcaudals.
Coloration grey or brown above, with a longitudinal zigzag band, usually spotted with white; head with or without spots on the vertex; black streak behind the eyes; ventral surface grey, spotted with black and white; tip of the tail usually yellow or with yellow spots.
Total length, 550-610 millimetres; tail 80-85.
Habitat: Spain and Portugal.
Vipera ammodytes.
([Fig. 21], 3 and 4).
Snout terminated in front by a horny appendage covered with 10-20 small scales; vertical diameter of the eyes less than the distance separating them from the mouth; upper surface of the head covered with small, smooth, or feebly keeled scales, among which an enlarged frontal and a pair of parietal shields are sometimes distinguishable; 5-7 longitudinal series of scales between the supraoculars; 10-13 scales round the eyes; two series between the eyes and the labials; nasal shield entire, separated from the rostral by a naso-rostral. Body scales in 21-23 rows, strongly keeled; 133-162 ventrals; 24-38 subcaudals.
Coloration grey, brown, or reddish above, with a zigzag dorsal band, usually spotted with white; black streak behind the eyes; belly grey or violaceous; end of the tail yellow, orange, or coral-red.
Total length, 550-640 millimetres; tail 70-80.
Habitat: Southern Tyrol, Carinthia, Styria, Hungary, Danubian principalities and kingdoms, Turkey. Does not pass beyond the 48th parallel of North Latitude.
This viper loves very sunny places, and hillsides planted with vines. It rarely hibernates.
In districts in which it is plentiful, it is only necessary to light a fire at night in order to attract this species in swarms; this is the best method of taking it.
Its food consists of small rodents, lizards, and birds.
B.—ASIA, DUTCH INDIES, AND PHILIPPINE ISLANDS.
The species of snakes most dangerous to man are found in the warmer regions of Asia. India especially is infested by the famous Cobra-di-Capello (Naja tripudians), which possesses the highly remarkable faculty of dilating its neck in the form of a hood when irritated, and whose sculptured image appears on almost all the Hindu monuments.
We shall describe in a separate section (see below, F.) the Hydrophiinæ, or Sea-snakes, a large number of species of which frequent the shores of the Indian Ocean, the Strait of Malacca, the China Sea, the Moluccas, Celebes, and North Australia. In the case of certain species the area of distribution includes the whole of the tropical and sub-tropical zones of the Pacific Ocean, as far as the West Coast of America. It is therefore preferable to group them together for the purpose of comprehensive study.
Besides the above, the continent of Asia harbours a multitude of poisonous snakes belonging to the two Families Colubridæ and Viperidæ.
The genera and species belonging to these are so diverse, that we must confine ourselves to mentioning the essential characters of those that present most interest.
| I.—Family Colubridæ. | |
|---|---|
| Subfamily Elapinæ: Genera | |
| { (a) Bungarus. | |
| { (b) Naja. | |
| { (c) Hemibungarus. | |
| { (d) Callophis. | |
| { (e) Doliophis. | |
(a) Bungarus.
Head hardly distinct from the neck; eyes small, with round or vertically elliptic pupils; nostril between two nasal shields. Two large poison-fangs followed by one or two small, slightly grooved teeth ([fig. 23]). Scales smooth, oblique, in 13-17 rows, enlarged and hexagonal in shape on the vertebral column; ventral scales round. Tail relatively short; subcaudal scales in one or two rows.
Two very dangerous snakes found in India and Indo-China belong to this genus, B. fasciatus and B. candidus (var. cæruleus). Both are fairly common. In Ceylon B. ceylonicus is met with, and in South China B. candidus (var. multicinctus). The length of these snakes is from 1,000-1,500 millimetres. The back is compressed in the shape of a keel. The neck is not dilatable.
Fig. 23.—Skull of Bungarus. (After G. A. Boulenger, op. cit.)
1. B. fasciatus (Banded Krait).
Colour bright yellow, ringed with black, with a black band commencing between the eyes, and broadening behind upon the nape and neck ([fig. 24]).
Especially abundant on the Coromandel Coast, in Bengal, and in Burma. In the North-west Provinces of India it is known as the Koclia-Krait. Its bite is very serious, but does not cause nearly so many fatalities as that of the Cobra, since its fangs are smaller.
Dogs bitten by B. fasciatus die in from four to five hours.
Fig. 24.—Bungarus fasciatus (India). (After Sir Joseph Fayrer.)
2. B. candidus.
Blackish-brown or bluish, with narrow transverse white streaks, or small white spots, or alternate rings of yellow and dark brown; belly white. Smaller than the foregoing, scarcely exceeding 1,000 millimetres in length. It is known as the “Krait” in India, where, after the Cobra, the variety cæruleus causes most deaths among human beings. It is found in jungles and rice-fields, and commonly secretes itself in old trees and old walls. It frequently penetrates into houses, verandahs, bathrooms, and even beds. Sir Joseph Fayrer relates the story of a lady, who, when travelling in a palanquin, found on arriving at her destination a “Krait” coiled up in her luggage, the snake having thus made the journey with her throughout a whole night.
The Krait may easily be confused with Lycodon aulicus, a harmless snake which closely resembles it, though it can at once be distinguished by examining its mouth.
(b) Naja.
([Fig. 25].)
Head scarcely distinct from the neck; eyes with round pupils; nostril between two nasal shields and an internasal. A pair of solid grooved poison-fangs. Body elongate, cylindrical, terminated by a conical and pointed tail. Scales smooth, disposed obliquely, in 15-25 rows. Ventral scales round.
N. tripudians (Cobra-di-Capello). ([Fig. 26].)
Head small, covered with large shields, a frontal as long as broad, a supraocular, a præocular, 3 postoculars, 2 + 3 or 3 + 3 temporals, 7 upper labials, 4 lower labials. Neck dilatable by the separation of the first cervical ribs; 21-35 scales round the neck, 17-25 round the middle of the body; 163-205 ventrals; 42-75 subcaudals.
Total length, 1,500-1,900 millimetres; tail 230.
Coloration very variable, usually cinereous grey or almost black with a bluish sheen; belly lighter, sometimes tinted with red. The head is frequently tinged with golden-yellow; it is spotted with yellowish-white above, and is pure white underneath.
This species is distributed throughout the whole of Southern Asia, from the south of the Caspian Sea to South China and the Malay Archipelago.
Fig. 25.—Skull of Naja tripudians. (After G. A. Boulenger, op. cit.)
Several varieties occur, and of these the principal are:—
(1) Var. Typica ([fig. 27]), with a black-and-white spectacle-shaped mark on the middle of the dorsal surface of the most dilatable portion of the neck, and one or more dark transverse bands on the ventral surface, behind the head.
Habitat: India, Ceylon.
(2) Var. Cæca.—Colour, pale brown or uniform dark grey, without mark on the neck, and with one or more dark transverse bands on the anterior part of the belly.
Habitat: Transcaspian region, India, Java.
Fig. 26.—Naja tripudians (Cobra-di-Capello) on the Defensive, preparing to Strike.
(3) Var. Fasciata.—Colour, brown, olive, or black, with more or less distinct light transverse bands. White spot edged with black in the shape of a ring or of a U on the neck, behind; a black spot on each side in front.
Habitat: India, Indo-China and South China, Hainan, Cambodia, Siam, Malay Peninsula.
(4) Var. Sputatrix.—Black or dark brown, with yellow or orange-coloured spots on the sides of the head and neck. The young have a pale spot in the shape of a U or an O on the middle of the dorsal surface of the neck, and the throat is whitish.
Habitat: Chusan Islands and South China, Burma, Malay Peninsula, Sumatra, Java.
(5) Var. Leucodira.—Brown or black, without mark on the neck. Throat yellowish-white, followed by a black transverse band.
Habitat: Sumatra, Malay Peninsula.
(6) Var. Miolepis.—Brown or black; sides of the head and throat yellowish, no mark on the neck. Young with white rings completely encircling the body and tail.
Habitat: Sarawak, Labuan, Borneo.
Fig. 27.—Naja tripudians (Cobra-di-Capello). (After Sir Joseph Fayrer.)
Naja samarensis.
Internasal shields shorter than the præfrontals, and in contact with the præoculars; 1-3 large occipital shields behind the parietals; 1 præocular and 3 postoculars; 2 + 2 or 2 + 3 temporals; 7 supralabials, 4 infralabials; 21-23 scales across the neck, 17-19 across the middle of the body; 159-175 ventrals; 45-50 subcaudals.
Coloration black or sometimes yellowish above; pale brown or yellowish on the belly; neck black.
Total length, 1,000 millimetres; tail 160.
Habitat: Philippine Islands.
Naja bungarus (Ophiophagus or Hamadryas elaps).
(King Cobra or Hamadryad.)
A pair of large occipital shields; 1 præocular; 3 postoculars; 2 + 2 temporals; 7 supralabials, 4 infralabials; 19-21 scales across the neck, 15 across the middle of the body; 215-262 ventral scales, 80-117 subcaudals. Neck dilatable.
Coloration very variable, yellowish, brown, olive, or black, with or without dark transverse bands.
Total length, 3,900 millimetres; tail 630.
Habitat: India, Burma, Indo-China, Siam, Southern China, Malay Peninsula and Archipelago.
The species of Naja are oviparous, and usually lay some twenty eggs, elliptical in shape and as large as those of a pigeon, with a soft shell.
These snakes do not fear the proximity of man, and feed upon rats, mice, and birds; they seek their prey chiefly in the evening, after sunset.
They swim extremely well, and frequent the neighbourhood of water-courses.
Indian legends relate that Brahma, having descended on earth and fallen asleep one day at high noon, a Naja placed itself in front of him and, dilating its broad neck, procured for him kindly shade. In order to repay it for the service rendered, Brahma gave Naja the marks that it bears on its neck, intended to frighten the kites and other birds of prey, which are implacable enemies of this snake.
When a native of the Malabar Coast finds a Naja in his dwelling, he begs it in a friendly way to depart; if the request be without avail, he offers it food in order to attract it outside; if the snake still does not move, the Hindu goes in search of the pious servitors of one of his divinities, who, procuring an offering, address the most touching supplications to it (Brehm).
The mortality due to the bite of this snake, which is by far the most common in India, is considerable. In the course of a period of eight years, from 1880 to 1887, it amounted on the average to 19,880 human beings and 2,100 head of cattle every year.
In 1889, 22,480 persons and 3,793 head of cattle perished from snake-bite. Since then, the annual tale of fatalities always fluctuates between 16,000 and 22,000, in spite of the rewards for the destruction of snakes which the Indian Government has been obliged to institute, which represent an expenditure of about £10,000 per annum.
For every 100 persons bitten, it is estimated that on an average from 25 to 30 die, and in most cases death supervenes in from two to twelve hours after the bite.
Naja bungarus, or the Hamadryad, is the largest and most formidable of poisonous snakes. It is very vigorous and very aggressive, but is more rarely met with than Naja tripudians. It loves the vicinity of rivers and streams, lives in forests and jungles, and climbs trees with facility. It feeds upon other snakes (whence its name Ophiophagus), and also on birds, fish, and small mammals.
Hindu snake-charmers assert that it is very difficult to capture, and dangerous owing to its strength; they handle it only after having extracted its poison-fangs.
A very intelligent Hindu told Torrens how he had seen the way in which the Hamadryad procures the snakes that form its favourite food. The Hindu in question happened to be on the flat roof of his house, when a young Hamadryad appeared quite close to him. The snake raised its head, expanded its neck, and emitted a shrill hissing noise. Thereupon a dozen snakes came crawling up from all directions and assembled round the Hamadryad, when the latter made a dart at one of them and hastened to devour it (Fayrer).
The Hamadryad is dreaded with good reason, for not only is it aggressive, and hurls itself boldly upon its adversary, but it also pursues him, a trait exhibited by no other poisonous snake.
Cantor relates that in Assam an officer met with several young Hamadryads which were being watched over by their mother. The latter turned towards its enemy, who took to his heels with all speed, pursued by the terrible reptile. The course taken led to a river, which the fugitive did not hesitate to swim in order to gain the opposite bank, hoping thus to make good his escape; all, however, to no purpose. The snake still pursued him, and the officer saved himself only by a stratagem. He dashed his turban on the ground; the snake threw itself upon it and savagely bit it several times, thus giving the officer time to reach a place of safety.
Cantor’s experiments show that the venom of the Hamadryad is extremely rapid in its action. A dog usually dies a quarter of an hour after being bitten, and Nicholson states that he has seen an elephant bitten by a snake of this species die in three hours.
(c) Hemibungarus.
This genus includes several species of snakes of somewhat small size, rarely exceeding 700 millimetres in length, with an elongate, cylindrical body; the head is scarcely distinct from the neck, the pupil round, and the tail short, while the nostril is situate between two nasal shields. The temporal shields are arranged in a single row. The poison-glands sometimes extend into the abdominal cavity. Scales in 13 or 15 rows; 190-260 ventrals, 12-44 subcaudals in 2 rows.
Four species belonging to this genus are known:—
(1) H. calligaster.—2 + 3 temporal scales, 6 supralabials.
Colour purple, with black transverse bands separated by narrow white bars; belly and end of tail red; snout yellow, with a black band on the upper lip below the eyes.
Total length, 520 millimetres; tail 30.
Habitat: Philippine Islands.
(2) H. collaris.—No anterior temporal scales.
Colour black on the back, with black and red bands on the belly; a yellow collar on the occiput.
Total length, 430 millimetres; tail 15.
Habitat: Philippine Islands.
(3) H. nigrescens.—Scales in 13 rows. A single temporal scale; 218-251 ventrals; 33-44 subcaudals.
Belly uniformly red; upper lip yellow in front of and behind the eyes.
Total length, 1,100 millimetres; tail 115.
Habitat: Hills of Western India, from Bombay to Travancore.
(4) H. japonicus.—Scales in 13 rows; 190-216 ventrals; 28-29 subcaudals; temporals 1 + 1.
Colour red on the back, with 1-5 black bands crossed by other black bands edged with yellow. Snout and sides of head black. Belly yellow, with large black spots alternating with black transverse bands.
Total length, 520 millimetres; tail 40.
Habitat: Loo Choo Islands.
(d) Callophis.
This genus is characterised by the maxillary bones extending forwards beyond the palatines, with a pair of large poison-fangs, but without other teeth. Head and eyes small, pupils round; nostril between two nasal shields. Body cylindrical, greatly elongate. Scales smooth, in 13 rows; ventrals rounded; subcaudals in 2 rows.
Five species are known:—
(1) C. gracilis.—Red or pale brown, with three longitudinal black lines passing through brown, or black spots; the lateral spots alternating with the vertebræ. Black and yellow bands under the tail and on the belly.
Total length, 740 millimetres; tail 35.
Habitat: Malay Peninsula, Sumatra.
(2) C. trimaculatus.—Head and nape black, with a yellow spot on each side of the occiput; belly uniform red; tail with two black rings.
Total length, 335 millimetres; tail 21.
Habitat: India and Burma.
(3) C. maculiceps.—Head and nape black, with one or two yellow bands on each side. Belly red, two black rings on the tail. Diameter of the eyes equal to two-thirds of the space separating them from the mouth.
Total length, 485 millimetres; tail 30.
Habitat: Burma, Indo-China, Malay Peninsula.
(4) C. macclellandii.—Head and neck black, with a yellow transverse band behind the eyes. The space separating the eyes equal to that separating them from the mouth. Colour reddish-brown on the back, with regular and equi-distant black streaks; belly yellow, with black bands or quadrangular spots. The head exhibits two black transverse bands separated by a yellow band.
Total length, 620 millimetres; tail 55.
Habitat: Nepal, Sikkim, Assam, Burma, Southern China.
(5) C. bibronii.—Met with by Beddome in the forests of Malabar, at an altitude of 3,280 feet. Back purplish-brown, with a pearly lustre, and about forty irregular black transverse bands, extending to the tip of the tail. Head black in front, cherry-red on the occiput.
Total length, 640 millimetres; tail 50.
Habitat: Malabar.
All the snakes belonging to the genus Callophis are remarkable for their bright and varied colours, whence the generic name, which signifies “beautiful snakes.”
They feed exclusively on other snakes belonging to the Family Calamaridæ; consequently they are not found in regions where Calamaridæ do not occur, as, for instance, in Ceylon.
They are essentially terrestrial, and live in old tree-trunks, or clefts in rocks. They are sluggish, slow-moving, and chiefly nocturnal.
As a rule they do not seek either to defend themselves or to bite; consequently fatal accidents caused by them are scarcely known in the case of human beings. Their venom, however, is very toxic to animals.
(e) Doliophis.
This genus exhibits the same characters as Callophis, except that the poison-glands, instead of being confined to the temporal region, extend a very long way on each side of the body, to about one-third of its length, gradually growing thicker and terminating at the base of the heart.
It includes four species:—
(1) D. bivirgatus.—Colour reddish-purple or black on the back, red on the head, tail, and belly.
Total length, 1,610 millimetres; tail 190.
Habitat: Burma, Indo-China, Malay Peninsula, Sumatra, Java, and Borneo.
(2) D. intestinalis.—Brown or black on the back, with darker or lighter longitudinal streaks; tail red beneath; belly red, crossed with black streaks.
Total length, 580 millimetres; tail 45.
Habitat: Burma, Malay Peninsula, Sumatra, Java, Borneo, Celebes.
(3) D. bilineatus.—Black on the back, with two white streaks along the whole length of the body. Snout white; belly striped with black and white bands. Tail orange, with two or three black rings or spots.
Total length, 710 millimetres; tail 45.
Habitat: Philippine Islands.
(4) D. philippinus.—Back with dark brown cross-bands, merging into black transverse ventral streaks, which are separated by yellow or red interspaces. Head brown, with small yellow spots.
Total length, 430 millimetres; tail 35.
Habitat: Philippine Islands.
II.—Family Viperidæ.
The Family Viperidæ is represented in Asia by a considerable number of snakes belonging to the two Subfamilies Viperinæ and Crotalinæ.
The Asiatic Viperinæ belong to the genera:—
(a) Vipera. (b) Pseudocerastes. (c) Cerastes. (d) Echis.
The Crotalinæ consist of only two genera:—
(e) Ancistrodon. (f) Lachesis.
1.—VIPERINÆ.
(a) Vipera.
We shall not recapitulate here the characters of the Genus Vipera, which we described in dealing with the vipers of Europe. The genus is represented by several species, the geographical range of which is chiefly confined to Eastern and Central Asia.
(1) Vipera renardi.—Resembles V. berus, but the snout is pointed and soft, with a turned-up tip; a single series of scales between the eyes and the lips; nostril pierced in the lower half of a single nasal shield; 8-9 supralabial shields; 4 infralabials. Body scales in 21 rows; 130-150 ventrals; 24-37 subcaudals.
Coloration the same as in the European V. ursinii, but the snout and lips are spotted with black or brown.
Total length, 395-620 millimetres; tail 40-75.
Habitat: Central Asia, Turkestan.
(2) V. raddii.—Snout rounded; supraocular shields erectile; eyes surrounded by a complete circle of 14-17 scales; 9-10 supralabials; body scales in 23 rows; 150-180 ventrals; 23-32 subcaudals.
Coloration pale brown or grey on the back, with a dorsal series of small reddish spots arranged in alternating pairs. A black mark like a circumflex accent on the occiput, and a black band behind the eyes. Belly yellow, speckled with black and white.
Total length, 740 millimetres; tail 50.
Habitat: Armenia.
(3) V. lebetina.—Snout rounded and obtuse, with a well-marked prominence; 7-12 longitudinal series of scales between the eyes; supraocular shields well developed or narrow, or broken up into several small portions; 12-18 scales round the eyes; 9-12 supralabials; 4-5 infralabials; body scales in 23-27 rows; 147-180 ventrals; 29-51 subcaudals.
Coloration variable, grey or pale brown on the back, with a series of large dark spots. Large brown mark like a circumflex accent on the crown of the head and another on the occiput. Belly whitish, speckled with grey-brown; end of tail yellow.
Total length, 960 millimetres; tail 120. The female may attain the length of 1,350 millimetres.
Habitat: Cyprus, Galilee, Syria, Asia Minor, Transcaspia, Persia, Mesopotamia, Afghanistan, Baluchistan, Cashmir.
(4) V. russellii (Daboia, or Russell’s Viper). ([fig. 28].)—This viper, which may attain a length of as much as 2,000 millimetres, is magnificently coloured. Its dorsal surface is brownish-yellow, marked with large oval spots of blackish-brown, edged with yellow or white. The belly is covered with transverse bands, with beautiful triangular black spots, bordered with white. The head, which is long, ends in front in a thick, rounded snout; it is covered above with small keeled scales. The nostril, which is large and laterally placed, is surrounded by three shields and soft smooth skin.
Fig. 28.—Vipera russellii (Syn. Vipera elegans. Daboia, or Russell’s Viper). India.
(After Sir Joseph Fayrer.)
The species is found throughout India, from Bombay to Bengal, in Ceylon, Burma, and Siam. It is particularly common in Burma, around Rangoon. For walking in the jungle and rice-fields, the natives of this region encase their feet and legs in a special kind of jack-boots made of coarse jute-cloth, in order to protect themselves from the bites of this snake, which cause a large number of fatal accidents.
The Daboia ascends the Himalayas to an altitude of 5,250 feet. It lives in thickets, under stones, and in the clefts of rocks. When disturbed it makes a terrible hissing, but bites only when attacked or irritated.
It feeds upon small vertebrates, such as mice, rats, birds, and frogs, and often enters houses in pursuit of rats.
“Schrott had the opportunity of observing a Daboia on the defensive. A lady carrying a child on her arm was returning home towards evening; she had almost reached her house when a bulldog accompanying her began to bark furiously. Although the lady saw nothing, she was, nevertheless, frightened and called for help. Schrott, who was not far away, ran to the spot, and saw a Daboia lying across the path by which the lady had to proceed. The reptile had its neck thrown back and its head in a horizontal position; its bright eyes followed all the movements of the dog, to whose barks it replied by shrill hisses. It was only waiting for an opportunity to strike. Schrott called off the dog, and the snake at once disappeared among the high grass close by. Next day it was killed at the same spot” (Brehm).
The venom of this viper is terribly potent. According to Russell, a large dog exhibited symptoms of poisoning five minutes after being bitten. At the end of a quarter of an hour it lay down, uttering heartrending cries, began to breathe with difficulty and noisily, was seized with spasms of the jaws and cramps, and died in frightful agony less than half an hour after the wound was inflicted. Fowls in most cases die in less than two minutes. A horse succumbed in half an hour, and another in eleven hours.
It appears that in India many cattle are killed by Daboias while grazing (Fayrer).
(b) Pseudocerastes.
([Fig. 29].)
This genus is represented by a single species (Pseudocerastes persicus), which appears to be exclusively confined to Persia.
The head is very distinct from the neck, and covered with small imbricate scales; the eyes, which are small, have vertical pupils; they are separated from the lips by small scales. The nostrils are directed upwards and outwards. The snout is very short and rounded. The cylindrical body has 23-25 rows of scales; 151-156 ventrals; 43-49 subcaudals.
Fig. 29.—Pseudocerastes persicus.
(After Duméril and Bibron.)
The coloration is gray or brown, with four series of large black spots, and the head exhibits two longitudinal black streaks behind the eyes. The belly is whitish, dotted with black.
Total length, 890 millimetres; tail 110.
(c) Cerastes.
The vipers belonging to this genus are much more common in North Africa, and we shall therefore study them in conjunction with the African snakes. Cerastes cornutus alone, the special habitat of which is Egypt, is sometimes met with in Arabia and on the eastern bank of the Suez Canal.
(d) Echis.
Echis carinatus (the Phoorsa). ([Fig. 30]).—This viper is characterised by the subcaudal shields being arranged in a single row. It is savage and very aggressive, being always ready to attack. Its length does not exceed 600 millimetres at the most. The colour of the body is grey, more or less dark and adorned with streaks, spots, and dots of blackish-brown. The back displays yellowish-white wavy lines, forming X-shaped markings. The upper side of the head exhibits a yellow spot surrounded by brown, and other small black spots, the whole arrangement forming a fairly good representation of a cross.
Fig. 30.—Echis carinatus. India. (After Sir Joseph Fayrer.)
This species is found in India, Persia, Baluchistan, Arabia, and Palestine; while, as we shall see, it also occurs in Africa. It is fairly common in the environs of Aden.
In moving over the ground a peculiar sound is produced by the friction of its scales. It is capable of springing with great agility a fairly long distance on to its prey. When it believes itself in danger it coils up, doubling its body twice in the shape of a crescent, in the middle of which it places its head, ready to strike. Its venom is very rapid in taking effect.
2.—CROTALINÆ.
(e) Ancistrodon.
The snakes belonging to this genus of Crotalinæ are found in Central and Eastern Asia, but three important species occur in the New World, in the United States and Central America. The head is covered with nine large symmetrical shields, but the internasals and præfrontals are sometimes broken up into scales. The body is cylindrical; the tail rather short; the subcaudal scales are arranged in one or two rows.
A. acutus.—The snout of this snake is prolonged into an appendage directed forwards. The head-shields are finely granulate. Body scales arranged in 21 rows; 162-166 ventrals; 58-60 subcaudals.
Coloration brown on the back, with blackish-brown X-shaped spots; head dark brown, yellow on the cheeks, with a black band running from the eye to the angle of the jaw; belly yellowish, spotted with brown, with a series of large black transverse blotches.
Total length, 1,500 millimetres; tail 200.
Habitat: Upper Yang-tse, China.
A. halys.—Snout prolonged into an upturned appendage, blunt at the tip; 7-8 supralabial scales, the third of which forms part of the margin of the eye; body scales in 23 rows; 149-174 ventrals; 31-44 subcaudals.
Coloration yellowish, grey, red, or pale brown above, with darker spots or cross-bars. A black spot on the snout; two black spots on the vertex; a dark, light-edged band on the temple; belly whitish, more or less speckled with grey or brown.
Total length, 490 millimetres; tail 65.
Habitat: From the borders of the Caspian Sea and the Ural River to the Upper Yenisei; Turkestan.
A. intermedius.—Resembles the foregoing very closely, but the snout is not turned up at the end.
Total length, 750 millimetres; tail 85.
Habitat: Central Asia, Eastern Siberia, Mongolia, and Japan.
A. blomhoffii.—Similar to A. halys, but the snout is not turned up at the end, and the body scales are in 21 rows; 137-166 ventral scales; 29-55 subcaudals.
Coloration very variable; grey, brown, or red above, with large black-edged spots arranged in pairs; black, light-edged band on the temple; upper lip uniformly yellow or red; belly yellow or reddish, more or less spotted with black, or almost entirely black.
Total length, 720 millimetres; tail 100.
Habitat: Eastern Siberia, Mongolia, China, Japan, Siam.
A. himalayanus.—Snout scarcely turned up, with a hard tip; 5-7 supralabial shields. Body scales in 21 (rarely 23) rows; 144-166 ventrals; subcaudals in 35-51 pairs.
Fig. 31.—Ancistrodon hypnale.
(The Carawalla of Ceylon.)
(After Sir Joseph Fayrer.)
Coloration brown, with black spots or transverse bands; black, light-edged band from the eye to the angle of the mouth; belly dark brown, or more or less whitish.
Total length, 590 millimetres; tail 90.
Habitat: Himalayas (5,000 to 10,000 feet), especially in the North-west; Khasi Hills.
This snake feeds chiefly on mice.
A. rhodostoma.—Snout pointed, somewhat turned up at the tip: 7-9 supralabial shields; body scales in 21 rows; 138-157 ventrals; 34-54 subcaudal pairs.
Coloration reddish, grey, or pale brown above, with large angular, dark brown, black-edged spots arranged in pairs or alternating. Vertebral line almost black; lips yellow, speckled with brown; brown, black-edged band, running from the eye to the angle of the mouth. Belly yellowish, spotted with greyish-brown.
Total length, 810 millimetres; tail 90.
Habitat: Java.
A. hypnale ([fig. 31]).—Snout more or less turned up, with a hard, pointed end; 7-8 supralabial shields; body scales in 17 rows; 125-155 ventrals; 28-45 subcaudal pairs.
Coloration very variable; brown, yellowish, or greyish above, sometimes with dark brown spots or transverse bands. Cheeks brown, with a longitudinal, white, black-edged streak on each side of the neck. Belly more or less speckled with dark brown.
Total length, 480 millimetres; tail 65.
Habitat: Ceylon, and Western Ghats of India as far north as Bombay.
In Ceylon this snake is known as the Carawalla. It is much dreaded, but its bite is not rapidly fatal.
(f) Lachesis.
This genus has many representatives in Asia and the New World. The American species are for the most part of larger size and more formidable.
They are characterised by a triangular head, covered with small scales or small shields, and by a cylindrical or compressed body. The Asiatic species have the subcaudal scales in two rows and the tail short, and often prehensile, which enables them to climb trees or bushes, where they lie in wait for their prey.
Their classification is based upon the following characters:—
A. First infralabial scale in contact with its fellow.
I. Scales in 21-25 (rarely 27) rows; 129-158 ventrals; 21-57 subcaudals; 5-9 series of scales between the supraocular shields; tail non-prehensile.
Fig. 32.—Lachesis okinavensis. (After G. A. Boulenger, op. cit.)
(1) L. monticola.—Supraocular shields large, separated by 5-8 scales; snout obtuse.
Colour brown or yellowish above, brown or pale yellow on the sides, with a brown temporal streak. Belly white, spotted with brown.
Total length, 740 millimetres; tail 115.
Habitat: Tibet, Himalayas (2,000 to 8,000 feet), Hills of Assam, Burma, Malay Peninsula, Singapore, Sumatra.
(2) L. okinavensis ([fig. 32]).—Supraocular shields large, separated by a transverse series of 6-9 scales; end of snout pointed and turned up.
Colour brown above, with dark transverse bands and a light temporal streak. Belly brown, spotted with black, especially on the sides.
Total length, 350 millimetres; tail 60.
Habitat: Okinawa, Loo Choo Islands.
(3) L. strigatus.—Supraocular shields small, sometimes broken up, separated by 8-11 convex scales in juxtaposition.
Colour brown above, with black spots often forming a median zigzag band; temporal band black; belly whitish, spotted with grey or black; end of tail yellow or reddish.
Total length, 480 millimetres; tail 55.
Habitat: Hills near Bombay, Deccan, Anamallays and Nilgherries.
II. Scales in 27-37 rows; 174-231 ventrals; 54-90 subcaudals; tail non-prehensile.
(4) L. flavoviridis.—Scales in 33-37 rows; 222-231 ventrals; 75-90 subcaudals; 8-9 supralabials.
Coloration pale brown or greenish-yellow above, marbled with black; longitudinal black streaks symmetrically disposed on the head; belly yellow or greenish, with darker spots.
Total length, 1,215 millimetres; tail 220.
Habitat: Loo Choo Islands.
This snake is not infrequently termed by naturalists Trimeresurus riukianus.
(5) L. cantoris.—Scales in 27-31 rows; 174-184 ventrals; 55-76 subcaudals; 13 supralabials.
Coloration pale brown or dull green, with small black spots; a whitish streak along the sides of the body; belly white or greenish.
Total length, 1,020 millimetres; tail 140.
Habitat: Andaman and Nicobar Islands.
III. Scales in 21-27 rows; 160-218 ventrals; 54-92 subcaudals; tail not or scarcely prehensile.
(6) L. jerdonii.—7-9 scales in a line between the supraocular shields; scales in 21 or 23 rows; 164-188 ventrals; 54-67 subcaudals.
Coloration greenish-yellow or olive above, mixed with black, a dorsal series of reddish-brown transverse rhomboidal spots; upper lip yellow, with one or two black spots; belly yellow, more or less marbled with black.
Total length, 930 millimetres; tail 145.
Habitat: Assam, Tibet, Upper Yang-tse.
(7) L. mucrosquamatus.—10-15 scales in a line between the supraocular shields; scales in 25-27 rows; 183-218 ventrals; 72-92 subcaudals. Colour brownish-grey above, with a series of large black median spots and smaller ones on the sides; a black streak from the eye to the angle of the mouth; belly brownish, spotted with white.
Total length, 1,050 millimetres; tail 210.
Habitat: Formosa, Assam.
(8) L. luteus.—12 or 13 scales in a line between the supraocular shields; scales in 23-25 rows; 182-186 ventrals; 72-74 subcaudals; supraocular shields large.
Colour yellow above, with a series of dark rhomboidal spots, and a dorsal, black-spotted zigzag band; a black streak on each side of the head behind the eyes; belly yellowish, spotted with grey.
Total length, 945 millimetres; tail 164.
Habitat: Loo Choo Islands.
(9) L. purpureomaculatus.—12-15 scales in a line between the supraocular shields; scales in 25-27 rows; ventrals 160-182; subcaudals 55-76; supraocular shield very narrow, sometimes broken up.
Coloration purplish-black above, sometimes variegated with pale green; flanks pale green; belly olive or greenish-white, uniform or spotted with black. Some specimens are entirely green.
Total length, 980 millimetres; tail 150.
Habitat: Himalayas, Bengal, Assam, Burma, Malay Peninsula, Andaman and Nicobar Islands, Pulo-Pinang, Sumatra.
IV. Scales in 21 rows (rarely 19 or 23); 7-13 series of scales between the supraoculars; tail more or less prehensile.
(10) L. gramineus (Syn. Trimeresurus gramineus. The Green Pit Viper).—145-175 ventral scales; 53-75 subcaudals; snout slightly projecting; supraocular shield narrow.
Colour bright green, rarely olive or yellowish, with or without darker transverse bands; end of tail yellow or red; belly green, yellow, or white.
Total length, 870 millimetres; tail 150.
Habitat: South-eastern Asia, Darjeeling, Himalayas, Ganges Delta, Siam, Southern China, Hong Kong, Formosa, Java, Sumatra, Timor.
Fig. 33.—Lachesis flavomaculatus.
(After G. A. Boulenger, op. cit.)
(11) L. flavomaculatus (fig. 33).—170-187 ventral scales; 53-73 subcaudals; snout projecting, obliquely truncate; supraocular shield narrow.
Colour bright green or olive, sometimes barred with reddish-brown; belly green, olive, or greenish-yellow; end of tail sometimes red.
Total length, 1,060 millimetres; tail 160.
Habitat: Philippine Islands.
(12) L. sumatranus.—180-191 ventral scales; 58-82 subcaudals; supraocular shield large.
Coloration bright green, with or without black transverse bands; yellowish band on each side; belly yellow or green, with or without black speckles; end of tail red.
Total length, 1,100 millimetres; tail 180.
Habitat: Singapore, Sumatra, Borneo, Palawan.
(13) L. anamallensis.—138-158 ventral scales; 44-58 subcaudals.
Colour green, olive, yellowish, or reddish-brown; a black temporal band; belly pale green, olive, or yellow; tail usually black and yellow.
Total length, 730 millimetres; tail 110.
Habitat: Anamallay and Nilgherry Hills, South India.
(14) L. trigonocephalus.—Scales in 17-19 rows, 145-170 ventrals; 53-67 subcaudals.
Coloration green, with or without black transverse bands or spots; a black temporal streak; belly green or yellow; end of tail usually black.
Total length, 790 millimetres; tail 130.
Habitat: Ceylon.
(15) L. macrolepis.—Scales in 13-15 rows; 134-143 ventrals; 48-56 subcaudals.
Colour bright green or olive; belly pale green.
Total length, 680 millimetres; tail 120.
Habitat: Southern India.
B. First lower labial shield divided; the portion separated off forms a pair of small supplementary dental shields; 144-176 ventral scales; 38-57 subcaudals; tail prehensile.
(16) L. puniceus.—Scales in 21-23 rows; 12-14 series of scales between the supraocular shields.
Colour grey, brown, or red; belly spotted with brown; end of tail red.
Total length, 640 millimetres; tail 90.
Habitat: Sumatra, Java, Borneo, Natuna Islands.
(17) L. borneensis.—Scales in 19-21 rows; 10-11 series of scales between the supraocular shields; 152-168 ventrals; 43-65 subcaudals.
Total length, 770 millimetres; tail 105.
Habitat: Borneo, Sumatra.
C. (18) L. wagleri.—Scales in 19-27 rows, 127-154 ventrals; 45-55 subcaudals; tail prehensile.
Colour green, with darker or lighter markings, black and yellow, or nearly entirely black.
Total length, 980 millimetres; tail 150.
Habitat: Malay Peninsula and Archipelago.
C.—AFRICA.
In Africa, poisonous snakes abound throughout the whole of the tropical and sub-tropical zones. The fatal accidents to human beings caused by them in this continent are fewer than in India, since the population of Africa is less dense, but several species occur, the venom of which is especially dangerous to life.
These species belong in nearly equal numbers to the Families Colubridæ and Viperidæ.
I.—Colubridæ.
The poisonous Colubridæ of Africa are all included in the Subfamily Elapinæ, of which the following are the eight principal genera:—
(a) Boulengerina. (b) Elapechis. (c) Naja. (d) Sepedon. (e) Aspidelaps. (f) Walterinnesia. (g) Homorelaps. (h) Dendraspis.
(a) Boulengerina.
A small snake 240 millimetres in length, the principal characters of which are as follows:—
Maxillary bones equal to the palatines in length, with a pair of relatively large poison-fangs, followed by three or four small teeth.
Head hardly distinct from the neck. Eye small, with round pupil; nostril between two nasal shields. Body cylindrical; scales smooth, in 21 rows; ventrals rounded. Tail moderate; subcaudal scales in 2 rows.
The only known species, B. stormsi, is brown, with black transverse bars on the neck; tail black; belly white in front, brown behind, with a black border to the scales.
It is found in the region of Lake Tanganyika.
(b) Elapechis.
This genus is characterised by the size of the maxillary bones, which is equal to that of the palatines; a pair of large poison-fangs followed by two to four small teeth; head not distinct from the neck; eye small with round pupil; nostril between two nasal shields. Body cylindrical; scales oblique, smooth, in 13 or 15 rows; ventrals rounded. Tail very short, subcaudal shields in 2 rows.
Six species are known:—
(1) E. guentheri.—Scales in 13 rows. Snout short, rounded; first lower labial shield in contact with its neighbour behind the symphysis. Internasal shorter than the præfrontals; length of frontal three-fourths of that of the parietals.
Coloration whitish or grey above, with black, white-edged cross-bands. Belly dirty white, brownish, or grey.
Total length, 520 millimetres; tail 50.
Habitat: Gaboon, Congo, Angola, Central Africa.
(2) E. niger.—Snout and arrangement of scales as before. Internasal shields three-fourths of the length of the præfrontals; frontal two-thirds of the length of the parietals.
Colour, black all over.
Total length, 420 millimetres; tail 30.
Habitat: Zanzibar.
(3) E. hessii.—Snout as in foregoing. Symphysial shield of the lower lip in contact with the anterior chin-shields.
Colour grey, with black cross-bars; a series of black spots on the sides, between the bars; large black blotch on nape; belly white.
Total length, 160 millimetres; tail 12.
Habitat: Congo.
(4) E. decosteri.—Snout obtusely pointed.
Colour, dark grey, each scale edged with black; belly white.
Total length, 380 millimetres; tail 38.
Habitat: Delagoa Bay.
(5) E. sundevallii.—Snout obtusely pointed.
Colour reddish-brown, with yellow transverse bands, the scales in which are edged with reddish-brown; upper lip and belly yellow.
Total length, 510 millimetres; tail 43.
Habitat: Caffraria.
(6) E. boulengeri.—Scales in 15 rows.
Colour black on the back, with narrow white transverse bands; head white, with a black streak along the parietal suture; belly blackish-grey.
Total length, 170 millimetres; tail 14.
Habitat: Zambesi.
(c) Naja.
(For the characters of this genus, see Asia, p. 33.)
Six species of Naja are found in Africa:—
(1) N. haje or haie.—Scales in 21-23 rows on the neck, which is dilatable, although slightly less so than that of N. tripudians, the Cobra-di-Capello of India.
Six or seven large supralabial shields, sixth or seventh in contact with the lower postocular. Eyes separated from the labial shields by the suboculars. 191-214 ventral scales; 53-64 subcaudals.
Colour yellowish, olive, or uniform black; belly yellowish; black or brown band on the neck; head sometimes blackish.
Total length, 1,180 millimetres; tail 290.
Habitat: Borders of the Sahara, Egypt, Southern Palestine, East Africa as far south as Mozambique.
Naja haje (the Egyptian Cobra) is common throughout the Nile Basin, the Sudan and Central Africa. Livingstone mentions it several times. In Egypt it is met with in the vicinity of ruined monuments, under the large blocks of stone or among brushwood.
The Egyptians are greatly in dread of it, and hunt it down as often as possible. When pursued, N. haje turns bravely and faces its adversary, raising itself upon its tail, puffing out its neck and hissing fiercely. If too hard pressed it strikes at its enemy.
“A friend of mine,” writes Anderson, “had great difficulty in escaping from one of these snakes. While botanising one day a Naja passed quite close to him. My friend darted backwards with all speed, but the Naja pursued and was about to attack him, when he stumbled against an ant-hill and fell flat on his back. This, no doubt, frightened the snake, which disappeared in a twinkling.”
Another case of the same kind is narrated by Waller, who writes: “A young girl met with her death in a truly dramatic fashion. She was walking behind some porters on a narrow path, when suddenly an Aspic came out of a thick bush, attacked and bit her in the thigh; in spite of all efforts to save her the unfortunate girl died in less than ten minutes.” This instance, which is absolutely authentic, proves the truth of the statements made by various travellers. Natives assert that a full-grown Naja invariably pursues either a man or an animal, however large, when either passes within its range (Brehm).
Snake-charmers, of whom there are many in Egypt, always employ Naja haje for their performances. They know how to capture it, and tear out its fangs by making it bite a bundle of rags.
This species rarely lives more than six or eight months in captivity, and is quite untamable. It is fond of bathing, and remains in the water for hours together.
“The Ancient Egyptians,” write Duméril and Bibron,[3] “are known to have worshipped the Naja, which they regarded as the protector of their crops. They allowed it to live and multiply among the cultivated lands, which they apparently entrusted to the care of their tutelary guardian, recognising that this snake freed them from the ravages of the rats, the immense number of which otherwise caused terrible destruction and even actual famine. It was, therefore, from motives of gratitude that the Egyptian Cobra was venerated in this way; that its image was hung up in the temples; that its skin was embalmed; and that its effigy, so easy to recognise and to reproduce roughly, was graven or sculptured on the stones of their monuments. This is the explanation of the fact that paintings representing N. haje are frequently reproduced in hieroglyphics and on Egyptian sarcophagi.”
The Naja was the tutelary deity of the temples, whose duty was to prevent the profane from entering. Thus, in one of the crypts of Denderah we find represented Serpent-genie, figures with a head like that of a Naja supported by the body of a man, with the hands armed with enormous cutlasses (Mariette, Dendérah, p. 91, 1875).
(2) N. flava.—Same arrangement of scales. Neck dilatable. 200-227 ventrals; 50-67 subcaudals.
Colour very variable, yellowish, reddish, brown, or black, uniform or with light spots; sometimes a black transverse band on the neck.
Total length, 1,470 millimetres; tail 230.
Habitat: South Africa.
(3) N. melanoleuca.—Coloration very variable. Sides of the head yellow or whitish; labial shields tinged with black on the posterior edge.
Total length, 2,400 millimetres; tail 400.
Habitat: Tropical Africa.
(4) N. nigricollis.—Third supralabial shield the deepest, sixth and seventh not in contact with the postoculars; 183-228 ventral scales; 55-68 subcaudals.
Coloration very variable; lower surface of the neck with a black transverse bar.
Total length, 2,000 millimetres; tail 300.
Habitat: From Senegambia and Upper Egypt to Angola and the Transvaal.
(5) N. anchietæ.—Scales in 17 rows on the neck and on the body; 181-192 ventrals; 52-62 subcaudals.
Colour blackish or brown above; end of snout and cheeks yellow; belly yellow or pale brown, with or without black cross-bar under the neck.
Total length, 1,800 millimetres; tail 340.
Habitat: Angola and Ovamboland.
(6) N. goldii.—Eyes large, two-thirds the length of the snout in adults. Scales in 15 rows on the neck and on the body; 194—195 ventrals; 88 subcaudals.
Colour black, uniform, or with transverse series of small whitish spots; cheeks and end of snout white, with a black border at the margin of the shields; belly white in front, black behind; subcaudal scales black.
Total length, 1,750 millimetres.
Habitat: Lower Niger.
(d) Sepedon.
Maxillary bones projecting considerably beyond the palatines, with a pair of large poison-fangs; no other maxillary teeth. Head not distinct from neck; eyes of moderate size, with round pupils; nostril between two nasal shields and an internasal. Body cylindrical; scales oblique, keeled, in 19 rows; ventrals rounded. Tail moderate; subcaudal scales in 2 rows.
S. hæmachates (The Spitting Snake, or Ring Hals Slang).—This snake, which is about 700 millimetres in length, is of a bluish-brown colour, with numerous narrow, undulating and denticulate cross-bands of yellow or yellowish-white. The throat is black or dark red; the belly grey.
It is met with throughout West, East, and South Africa, as far as the Cape of Good Hope, where it is very common. It lives among bushes in sandy places, where the ground is full of the holes of rats, moles, and small rodents, upon which it feeds. It is very active and exhibits great ferocity.
Natives at the Cape declare that this snake is able to project its venom to a distance of more than a yard, especially if the wind is blowing in the same direction, and that, if the poison happens to enter the eye, the inflammation that results therefrom often leads to loss of sight (Smith).
As to this, a very definite statement is given by Bavay,[4] on the authority of Le Naour:—
“While hunting in Dahomey,” wrote Le Naour to Bavay, “I thrice met with the snake called the Spitter. On two occasions my dog was struck in both eyes by the liquid projected by the reptile. Immediately (less than two minutes afterwards), symptoms of conjunctivitis manifested themselves, with considerable swelling of the pupils; the conjunctivitis seemed as though it were going to be very serious, and yielded only after twelve days’ treatment with boracic lotion, aided by a few cauterisations with sulphate of copper.
“During my sojourn at Porto-Novo, a store-keeper at the Dogba trading station was a victim of the Spitter. While working at his store he received in his eye a jet of liquid, which produced violent conjunctivitis.”
(e) Aspidelaps.
Maxillary bones extending forwards beyond the palatines, as in Sepedon, with a pair of large poison-fangs; no other maxillary teeth. Head slightly distinct from the neck. Eyes of moderate size, with round or vertically elliptic pupils. Rostral shield very large, detached on the sides. Body cylindrical; scales oblique, smooth or keeled, in 19-23 rows; ventrals rounded. Tail short, obtuse; subcaudal scales in 2 rows.
(1) A. lubricus.—146-167 ventral scales; 20-28 subcaudals.
Colour orange or red, with black rings; a black bar below the eyes; upper surface of head sometimes entirely black.
Total length, 590 millimetres; tail 55.
Habitat: Cape Colony and Namaqualand.
(2) A. scutatus (Fula-fula of Mozambique).—115-135 ventrals; 24-38 subcaudals.
Colour pale grey, with black spots or cross-bars, and a black mark shaped like a circumflex accent on the head. A black collar encircling the neck, and a black vertical streak below the eye. Belly whitish.
The total length may be as much as 520 millimetres.
Habitat: Natal, Delagoa Bay, Mozambique.
(f) Walterinnesia.
Maxillary bones prolonged forwards beyond the palatines, with a pair of large poison-fangs; no other maxillary teeth. Head distinct from the neck; eyes rather small, with round pupils; nostril between two or three nasal shields and the internasal. Body cylindrical; scales smooth or feebly keeled, in 23 rows; ventrals rounded. Tail rather short; subcaudal scales for the most part in 2 rows.
W. ægyptia.—Colour blackish-brown on the back, paler on the belly.
Total length, 1,170 millimetres; tail 170.
Habitat: Egypt.
Fig. 34.—Skull of Dendraspis viridis (Poisonous West African Colubrine). (After G. A. Boulenger, op. cit.)
(g) Dendraspis.
([Fig. 34].)
Maxillary bone curved upwards, bearing a pair of powerful poison-fangs, not fissured, and not followed by other teeth; a long tooth at the end of each ramus of the mandible. Head narrow, elongate; eye moderate, with round pupil; nostril between two shields. Body slightly compressed; scales smooth, narrow, very oblique, in 13-23 rows; ventrals rounded. Tail long; subcaudals in 2 rows.
(1) D. viridis.—211-225 ventral scales; 107-119 subcaudals.
Colour uniform olive-green. Shields on the head edged with black; lips yellow; belly and tail yellow, with scales and shields bordered with black.
Total length, 1,830 millimetres; tail 460.
Habitat: West Africa, from the Senegal to the Niger; St. Thome Island.
(2) D. jamesonii.—Coloration as before. Scales in 15-19 rows (19-21 on the neck); 210-235 ventrals; 99-121 subcaudals. Tail sometimes black.
Total length, 2,100 millimetres; tail 560.
Habitat: West Africa, from the Niger to Angola; Central Africa.
(3) D. angusticeps (The Mamba).—202-270 ventral scales; 99-121 subcaudals.
Colour green, olive, or blackish, uniform; belly yellowish or pale green; caudal scales and shields not bordered with black.
Total length, 2,000 millimetres; tail 430.
Habitat: West Africa, south of the Congo; Central Africa, East Africa, Transvaal, Natal.
(4) D. antinorii.—Scales in 21-23 rows; 248 ventrals; 117 subcaudals. Colour olive on the back, yellowish on the belly.
Total length, 2,690 millimetres; tail 545.
Habitat: Abyssinia.
II.—Viperidæ.
The African Viperidæ all belong to the Subfamily Viperinæ, of which the following are the seven principal genera:—
(a) Causus. (b) Vipera. (c) Bitis. (d) Cerastes. (e) Echis. (f) Atheris. (g) Atractaspis.
(a) Causus.
([Fig. 35].)
Head distinct from the neck, covered with symmetrical shields; nostril between two nasal shields, and the internasal; eyes moderate, with round pupils, separated from the lips by subocular shields. Body cylindrical; scales smooth or keeled, oblique on the sides, in 15-22 rows; ventral scales rounded. Tail short; subcaudals in 2 rows or single.
Four species:—
(1) C. rhombeatus.—Snout obtuse, moderately prominent. Scales in 17-21 rows; 120-155 ventrals; 15-29 subcaudals.
Colour olive or pale brown, usually with a series of V-shaped brown spots bordered with white, and a large spot in the form of a circumflex accent at the back of the head; lips bordered with black; belly yellowish or grey.
Total length, 700 millimetres; tail 75.
Habitat: Tropical and South Africa, from the Gambia to the Cape.
(2) C. resimus.—Snout prominent, more or less turned up; scales in 19-22 rows; 134-152 ventrals; 17-25 subcaudals.
Colour greyish-olive on the back; uniform white on the belly.
Total length, 470 millimetres; tail 40.
Habitat: Central and East Africa, Angola.
(3) C. defilipii.—Snout prominent, more or less turned up. Scales in 17 rows; 113-125 ventrals; 10-18 subcaudals.
Colour grey or pale brown above, with a series of large rhomboidal or V-shaped blackish-brown spots; a large A-shaped dark brown mark on the occiput; an oblique dark streak behind the eye; supralabial shields edged with black; belly yellowish.
Total length, 400 millimetres; tail 22.
Habitat: Central and East Africa, Transvaal.
Fig. 35.—Skull of Causus rhombeatus. (After G. A. Boulenger, op. cit.)
(4) C. lichtensteinii.—Snout obtuse; scales in 15 rows; 142-144 ventrals; subcaudals 15-21, single.
Colour greyish, with rather indistinct darker chevron-shaped cross-bands.
Total length, 413 millimetres; tail 35.
Habitat: West Africa (Gold Coast), Congo.
(b) Vipera.
(For the characters of this genus, see p. 23,—Europe.)
In North Africa are found Vipera latastii, V. ammodytes, and especially V. lebetina, the range of which extends from Morocco to Northern India. Vipera superciliaris, which occurs on the coast of Mozambique, has the snout rounded, and the head covered with small, imbricate, keeled scales, with a large supraocular shield; nostril very large, between two nasal shields; scales on the body strongly keeled, in 27 rows; 142 ventrals; 40 subcaudals.
The colour is pale reddish-brown or orange, with blackish transverse bars broken by a longitudinal yellow band on each side; the belly is white, spotted with black.
Total length, 570 millimetres; tail 77.
(c) Bitis.
([Fig. 36].)
The Viperidæ belonging to this genus have the head very distinct from the neck, covered with small imbricate scales; the eyes rather small, with vertical pupils, separated from the lips by small scales; the nostrils directed upwards and outwards, usually pierced in a single nasal shield, with a rather deep pit above, closed by a valvular supranasal. The postfrontal bones are very large, in contact with the ectopterygoids. Scales keeled, with apical pits, in 22-41 rows; ventrals rounded. Tail very short; subcaudal scales in 2 rows.
(1) B. arietans (the Puff Adder; [fig. 37]).—This viper has the nostrils on the upper surface of the snout, and two series of scales between the supranasal shields; 12-16 supralabials; 3-5 lower labials. The scales on the body are in 29-41 rows, and strongly keeled; ventrals 131-145; subcaudals 16-34.
The body is thick, the head large and triangular, and the tail very short. The colour is dirty yellow or orange, with large, transverse or oblique, chevron-shaped black bands; an oblique black band extends behind the eye. The belly is dirty yellow, uniform, or marked with small black spots.
Total length, 1,350 millimetres, sometimes more; tail 160.
Fig. 36.—Skull of Bitis arietans (the Puff Adder). (After G. A. Boulenger, op. cit.)
Habitat: This snake is met with throughout Africa, from Southern Morocco, Kordofan, and Somaliland, to the Cape of Good Hope, and also in Southern Arabia. It is especially common near the Niger and on the Congo.
When irritated, it puffs itself out to such an extent that its body becomes twice the ordinary size. It then doubles back its head and neck in the shape of an S, and emits a loud and prolonged hiss. Before biting, it first strikes a blow with its head as with a battering-ram, thus justifying its French name, vipère heurtante (Striking Viper).
Fig. 37.—Bitis arietans (the Puff Adder). (After Duméril and Bibron.)
The natives of South Africa assert that this Viper is able to spring high enough to strike a rider on horseback. It feeds upon rats and mice, in search of which it often approaches habitations.
The Hottentots hunt it in order to obtain its venom; they pound its head between stones, and mix the pulp with the juice of certain plants for the purpose of poisoning their arrows.
It lives for a fairly long time in captivity. At the Pasteur Institute at Lille I have succeeded in keeping one of these snakes for two years, feeding it by forcing milk and eggs down its throat.
(2) B. peringueyi.—Nostrils opening upwards and outwards. Head covered with small, strongly keeled scales, which are smallest on the vertex; 11 scales round the eye; 3 series of scales between the eye and the lip; 11-14 supralabials. Scales on the body in 25-27 rows, strongly keeled; 130-132 ventrals; 19-28 subcaudals.
Colour greyish-olive, with 3 longitudinal series of grey or blackish spots; head sometimes with a trident-shaped dark mark, followed by a cross; under surface whitish, with small dark spots.
Total length, 325 millimetres; tail 26.
Habitat: Angola and Damaraland.
(3) B. atropos.—Nostrils opening upwards and outwards, 13-16 scales round the eye; 2-5 series of scales between the supranasals; 10-12 supralabials; 3-4 infralabials. Scales on the body in 29-31 rows, all strongly keeled; 124-145 ventrals; 18-29 subcaudals.
Colour brown or grey-brown, with 4 longitudinal series of dark spots, edged with black and white; two large black marks on the head; belly grey or brown, with darker spots.
Total length, 350 millimetres; tail 25.
Habitat: Cape of Good Hope.
(4) B. inornata.—Eyes smaller than in B. atropos, and separated from the lips by 4 series of scales; supraorbital region raised, but without erect horn-like scales; 15-17 scales across the head; 13-14 supralabials; 3 lower labials. Scales on the body in 27-29 rows, all keeled; 126-140 ventrals; 19-26 subcaudals.
Total length, 350 millimetres; tail 30.
Habitat: Cape of Good Hope.
(5) B. cornuta ([fig. 38]).—Nostrils opening upwards and outwards. Head covered with small, imbricate, strongly keeled scales; 2-5 raised scales, like horns, above each eye; 12-14 scales round the eye; 12-15 supralabials; 2-3 infralabials. Scales on the body keeled, in 25-29 rows; 120-152 ventrals; 18-36 subcaudals.
Colour grey or reddish-brown, with black spots, edged with white and arranged in 3 or 4 longitudinal series; a dark, oblique streak from the eye to the mouth; belly yellow or brown, uniform or spotted.
Total length, 510 millimetres; tail 35.
Fig. 38.—Bitis cornuta.
(After Duméril and Bibron.)
Habitat: Cape Colony, Namaqualand, Damaraland.
(6) B. caudalis.—Nostrils opening upwards and outwards. 12-16 scales from one eye to the other across the head; above each eye a single, erect, horn-like scale; 10-16 scales round the eye; 10-13 supralabials; 2-3 infralabials. Scales on the body in 22-29 rows, strongly keeled; 112-153 ventrals; 18-33 subcaudals.
Colour reddish or sandy-grey, with 2 series of brown spots with light centres, and frequently a vertebral series of narrow spots; belly dull yellow, uniform, or with small black spots on the sides.
Total length, 360 millimetres; tail 25.
Habitat: South-west Africa, from Angola to Namaqualand.
(7) B. gabonica (Gaboon Viper, or River Jack Viper).—Nostrils directed upwards and outwards. Head covered with small, moderately keeled scales, smallest on the vertex, 13-16 from eye to eye; 15-19 scales round the eye; a pair of erectile, triangular, nasal “horns,” consisting of sometimes tricuspid shields, between the supranasals; 13-16 supralabials; 4-5 infralabials. Scales on the body in 33-41 rows, strongly keeled; lateral scales slightly oblique; 125-140 ventrals; 17-33 subcaudals.
This viper, which often attains a length of 1,200 millimetres, is brown, with a vertebral series of quadrangular, yellowish, or light brown spots connected by black markings; the belly is dull yellow, with small brown or blackish spots.
Habitat: Tropical Africa (West Africa, from Liberia to Damaraland; Zanzibar, Mozambique).
This species, which is nocturnal, is often met with on the Gaboon, and in the forests near the banks of the Ogowai. Its head is enormous, triangular in shape, and wider above; it has a bulky body, and a very short tail, terminating abruptly in a point.
The Gaboon Viper is a savage snake, with very active venom, and its poison-glands are of the size of large almonds. It lives in virgin forests, among dead wood and rocks. I have several times met with it in manioc plantations on the edge of the woods. In broad daylight it is sluggish, moves somewhat slowly, and never attacks man. It bites only when surprised.
Fig. 39.—Bitis nasicornis.
(After Duméril and Bibron.)
(8) B. nasicornis ([fig. 39]).—Nostrils opening upwards and outwards. Head covered with small strongly keeled scales, smaller on the vertex, 14-16 from one eye to the other; 2 or 3 pairs of compressed, erectile, horn-like shields between the supranasals, usually separated in the middle by 1 or 2 series of small scales; 15-18 supralabials; 4-6 infralabials. Scales on the body in 35-41 rows, strongly keeled; 124-140 ventrals; 16-32 subcaudals.
Colour purple or reddish-brown above, with pale olive or dark brown spots; a vertebral series of brown, black-edged spots, which assume a rhomboidal form; sides of head dark brown, with a triangular light mark in front of the eye, and an oblique light streak from behind the eye to the mouth; belly pale olive, spotted with black or yellow.
Total length, 1,250 millimetres; tail 125.
Habitat: West Africa, from Liberia to the Gaboon.
(d) Cerastes.
Head very distinct from the neck, covered with small juxtaposed or slightly imbricate scales; eyes small, with vertical pupils, separated from the lips by small scales; nostrils opening upwards and outwards. Body cylindrical; scales keeled, with apical pits, in 23-35 rows. Tail short; subcaudals in 2 rows.
(1) C. cornutus ([fig. 40]).—Snout very short and broad; two erectile horns above the eyes, which are separated by 15-21 scales and surrounded by 14-18; 4-5 series of scales between the eyes and the lips; 12-15 supralabials; 3 infralabials; scales on the body in 27-35 rows; 130-165 ventrals; 25-42 subcaudals.
Fig. 40.—Cerastes cornutus.
(After Duméril and Bibron.)
Colour yellowish-brown or grey, with or without brown spots, forming 4-6 regular series, the two middle ones sometimes forming cross-bars; an oblique dark streak behind the eye; belly white; end of tail sometimes black.
Total length, 720 millimetres; tail 90.
Habitat: Northern border of the Sahara, Egypt, Nubia, Arabia, and Southern Palestine.
(2) C. vipera.—Snout very short and broad; head covered with small, tubercularly keeled scales, to the number of 9-13 from eye to eye; no “horns”; 9-14 scales round the eye; nostril between two small shields, separated from their neighbours by 5-6 series of scales; 10-12 supralabials; 3 infralabials. Scales on the body in 23-27 rows; 102-122 ventrals, rather strongly keeled at the sides; 18-26 subcaudals. Colour dull yellow, pale brown or reddish, with or without black spots; end of tail often black above; ventral surface white.
Total length, 340 millimetres; tail 30.
Habitat: Northern border of the Sahara, from Algeria to Egypt.
The snakes belonging to this genus live constantly hidden in the sand, lying in wait for small birds, which alight beside them without suspicion, mistaking their horns for insects or larvæ; they also feed upon mice. Their poison-fangs are of relatively large size.
These small and exceedingly active vipers, whose colour harmonises marvellously with their surroundings, are very dangerous to the Arabs and blacks, who walk barefooted; they frequently cause fatal accidents.
They are able to exist for a very long time without drinking. They are attracted by the fires which are lighted at night round caravan encampments.
(e) Echis.
(See Asia, p. 48.)
(1) E. carinatus (Efa, Viper of the Pyramids).—The same as met with in Persia, Arabia, and India. Very common in the environs of Cairo, and throughout Egypt and Abyssinia. It often makes its way into towns and villages. Brehm records that he more than once found an Efa in his house at Khartoum, and that on one occasion he discovered one of these vipers coiled up beneath the covering of his bed. At another time, getting up in the night, he put his foot on one of these animals and was not bitten, the reptile being very fortunately just at that moment in the act of devouring a tame bird which it had seized.
It hardly ever happens that a native of Egypt can bring himself to destroy an Efa, of which he has the greatest dread. If, as often occurs, he finds one of these reptiles in his house, he addresses himself to the Hani or juggler, in order that, by his magic art, he may expel the dangerous visitor. From this custom the juggler evidently derives no small advantage, for, as is only right, he does not ply his craft for nothing. In many cases, indeed, the juggler releases a snake in a house, and then goes and informs the owner that he knows that a reptile is concealed in his dwelling, and that, in consideration of a stipulated reward, he will rid him of it (Brehm).
Fig. 41.—Echis coloratus. (After G. A. Boulenger, op. cit.)
(2) E. coloratus ([fig. 41]).—Scales on the snout and vertex convex, smooth or bluntly keeled, 13-15 from eye to eye; no supraocular shield; 17-22 scales round the eye; 12-15 supralabials; scales on the body in 31-35 rows; 174-205 ventrals; 42-52 subcaudals. No cruciform mark on the head.
Total length, 750 millimetres; tail 80.
Habitat: Palestine, Arabia, Socotra.
(f) Atheris.
Head very distinct from neck, covered with imbricate scales; eyes large, with vertical pupils, usually separated from the labial shields by small scales; nostrils lateral. Body slightly compressed; scales keeled, with apical pits. Tail moderate, prehensile; subcaudal scales in a single row.
(1) A. chlorechis.—No supraciliary horn-like scales; 9-11 scales from eye to eye; 25-36 rows of scales in the middle of the body, strongly keeled; 154-165 ventrals; 53-62 subcaudals.
Colour green, uniform or with small yellow spots; end of tail yellowish or blackish.
Total length, 520 millimetres; tail 85.
Habitat: West Africa, from Liberia to the Ogowai.
(2) A. squamiger.—No supraciliary horn-like scales; 7-8 scales from eye to eye; 15-25 rows of scales in the middle of the body, strongly keeled; 153-173 ventrals; 51-95 subcaudals.
Colour olive, uniform or with more or less regular, narrow yellow cross-bands, or yellow with green spots; belly pale olive, marbled with black or yellow, or uniform yellow.
Total length, 550 millimetres; tail 100.
Habitat: West Africa, from the Cameroons to Angola.
(3) A. ceratophorus.—Several erect, supraciliary horn-like scales; 9-10 scales from eye to eye; 25 rows of scales in the middle of the body, strongly keeled; 142 ventrals; 55 subcaudals.
Colour dark olive, with black spots forming cross-bands; belly pale olive, speckled with black.
Total length, 210 millimetres; tail 65.
Habitat: East Africa.
(g) Atractaspis.
([Fig. 42].)
This genus is characterised by enormous poison-fangs, a few teeth on the palatines, and none on the pterygoids. The mandible, which is edentulous in front, has only two or three small teeth in the middle of the dentary bone. Head small, not distinct from the neck, covered with large symmetrical shields; nostril between two nasal shields; eyes minute, with round pupils; postfrontal bone absent. Body cylindrical; scales smooth, in 17-37 rows; ventrals rounded. Tail short; subcaudals in 1 or 2 rows.
(1) A. hildebrandtii.—Six supralabials; no præocular shields; frontal shorter than the parietals; scales on the body in 17 rows; ventrals 167-174.
Colour uniform dark brown.
Total length, 450 millimetres; tail 53.
Habitat: East Africa.
(2) A. congica.—Five supralabials, of which the fourth is the larger; postocular in contact with a large temporal; one præocular; frontal as long as or slightly shorter than the parietals. Scales on the body in 19-21 rows; 209-230 ventrals; 19-23 subcaudals.
Fig. 42.—Skull of Atractaspis aterrima (African Viperine). (After G. A. Boulenger, op. cit.)
Colour uniform dark brown or black.
Total length, 450 millimetres; tail 35.
Habitat: Congo, Angola.
(3) A. irregularis.—Characters as before, but scales on the body in 25-27 rows; 220-257 ventrals, subcaudals 22-28 pairs.
Colour uniform black or dark brown.
Total length, 560 millimetres; tail 35.
Habitat: West Africa, from the Gold Coast to the Congo; Central Africa.
(4) A. corpulenta.—Postocular shield in contact with a large temporal; second lower labial very large, fused with the chin-shields. Scales on the body in 23-27 rows; 178-193 ventrals; 23-27 subcaudals.
Colour uniform blackish-brown; tail sometimes white.
Total length, 345 millimetres; tail 33.
Habitat: West Africa, from Liberia to the Gaboon.
(5) A. rostrata.—Snout very prominent, cuneiform. Third lower labial very large; first lower labial in contact with its fellow, behind the symphysial. Scales on the body in 19-23 rows; ventrals 227-248.
Colour uniform dark brown, or blackish.
Total length, 600 millimetres; tail 37.
Habitat: East and Central Africa.
(6) A. bibronii.—Characters as before. Snout prominent, subcuneiform. Ventral scales, 221-260.
Colour dark purplish-brown above, dull yellow or pale brown on the belly.
Total length, 600 millimetres; tail 25.
Habitat: Eastern districts of Cape Colony, Natal, Namaqualand, Angola.
(7) A. aterrima.—Characters as before. Snout rounded; 251-300 ventral scales.
Colour uniform dark brown or black.
Total length, 650 millimetres; tail 30.
Habitat: West and Central Africa.
(8) A. dahomeyensis.—Characters as before. Symphysial shield in contact with the chin-shields. Scales on the body in 31 rows; 240 ventrals; 24 subcaudals.
Colour black above, brown on the belly.
Total length, 490 millimetres; tail 32.
Habitat: Dahomey.
(9) A. micropholis.—Temporal shields small, 2 + 3 or 4; fourth or fifth infralabial larger; scales on the body in 25 rows; 210-215 ventrals; 29-30 subcaudals. Frontal shield slightly longer than broad, much longer than the parietals.
Colour uniform dark brown.
Total length, 330 millimetres; tail 28.
Habitat: Cape Verd.
(10) A. leucomelas.—Characters as before. Frontal one and two-fifths as long as broad, as long as the parietals.
Colour black, with a vertebral white line, occupying one row and two half rows of scales; ventrals and subcaudals white; neck black, head white, with a black spot covering the nasals and upper head-shields.
Total length, 575 millimetres; tail 40.
Habitat: Somaliland.
(11) A. microlepidota.—Characters as before. Scales on the body in 29-37 rows; 212-245 ventrals; 26-37 subcaudals.
Colour uniform dark brown.
Total length, 540 millimetres; tail 45.
Habitat: Central and East Africa.
D.—AUSTRALIA AND THE LARGE ADJACENT ISLANDS.
The Sunda Islands and the whole of Malaysia are rich in poisonous snakes. Those that are found there belong for the most part to species that we have already met with in India or the Malay Peninsula. We shall therefore not describe them again here.
All those that inhabit Australia are included in the great Family Colubridæ and the Subfamily Elapinæ. There are no Viperidæ; but certain genera of poisonous Colubridæ are peculiar to this continent.
These reptiles have been particularly well studied by Gérard Krefft, formerly Director of the Australian Museum at Sydney, from whose work[5] we shall borrow a considerable portion of the following notes, and the figures accompanying them.
The genera represented in Australia are:—
| (a) | Ogmodon. |
| (b) | Glyphodon. |
| (c) | Pseudelaps. |
| (d) | Diemenia. |
| (e) | Pseudechis. |
| (f) | Denisonia. |
| (g) | Micropechis. |
| (h) | Hoplocephalus. |
| (i) | Tropidechis. |
| (j) | Notechis. |
| (k) | Rhinhoplocephalus. |
| (l) | Brachyaspis. |
| (m) | Acanthophis. |
| (n) | Elapognathus. |
| (o) | Rhynchelaps. |
| (p) | Furina. |
(a) Ogmodon.
This genus is characterised by the maxillary bones extending forwards as far as the palatines, and bearing, in addition to the poison-fangs, 6-7 grooved teeth. The head is not distinct from the neck; the eyes are very small. The body is cylindrical, and covered with smooth scales in 17 rows. Tail short; subcaudal scales in 2 rows.
O. vitianus.—Snout elongate, pointed; 139-152 ventral scales; 27-38 subcaudals.
Colour dark brown, lighter on the sides; belly brown or white, more or less spotted with black; tail black.
Total length, 360 millimetres; tail 45.
Habitat: Fiji Islands.
Fig. 43.—Skull of Glyphodon tristis (Australian Colubrine).
(After G. A. Boulenger, op. cit.)
(b) Glyphodon.
General characters the same; snout rounded; poison-fangs followed, after a wide interspace, by 6 small grooved teeth; anterior mandibular teeth strongly developed ([fig. 43]). Head and eyes small; pupils round or vertically subelliptic; nostrils pierced between 2 nasal shields. Body cylindrical; scales smooth, in 17 rows; tail short; subcaudals in 2 rows.
G. tristis.—Ventral scales 165-179; subcaudals 38-52.
Colour dark brown; occiput often yellowish, or pale reddish-brown; belly yellow.
Total length, 900 millimetres; tail 125.
Habitat: North-eastern Australia and South-eastern New Guinea.
(c) Pseudelaps.
Maxillaries extending forwards as far as the palatines, with a pair of large grooved poison-fangs, and, after a wide interval, 8-12 small grooved teeth. The anterior mandibular teeth are of large size, almost like fangs. Head hardly distinct from the neck; eyes small, with vertically elliptic pupils. Body cylindrical; scales smooth, in 15-17 rows. Tail moderate or short; subcaudal scales in 2 rows.
(1) P. muelleri.—Scales in 15 rows. Nasal shield divided, in contact with the præocular; 2 + 2 temporals; 139-176 ventral scales; 21-35 subcaudals.
Colour brown, with a light vertebral line; a more or less distinct dark, light-edged streak on each side of the head, passing through the eye; belly yellowish or coral-red; uniform or spotted with black.
Total length, 500 millimetres; tail 70.
Habitat: Moluccas, New Guinea, New Britain.
(2) P. squamulosus.—Scales in 15 rows. Nasal shield divided, in contact with the præocular; 1 + 2 temporals; 170-183 ventrals; 34-52 subcaudals.
Colour brown, with a yellowish streak round the snout and through the eyes to the nape; belly whitish, with confluent black spots forming lines on each side.
Total length, 375 millimetres; tail 55.
Habitat: New South Wales.
(3) P. krefftii ([fig. 44]).—Nasal shield entire, in contact with the præocular; 1 + 2 temporals; 146-156 ventrals; 26-38 subcaudals.
Colour dark brown, with a light longitudinal line on each scale; a yellowish cross-band on the occiput, connected with another yellow band which encircles the snout.
Belly yellowish in front, black behind; subcaudals white, with a longitudinal black band running between them.
Fig. 44.—Pseudelaps krefftii.
Fig. 45.—Pseudelaps harriettæ.
Fig. 46.—Pseudelaps diadema.
Total length, 255 millimetres; tail 33.
Habitat: Queensland.
(4) P. harriettæ ([fig. 45]).—Nasal shield entire, in contact with or narrowly separated from the præocular; 1 + 2 temporals; 176-193 ventrals; 29-35 subcaudals.
Colour dark brown, with a light longitudinal line on each scale; a long yellow blotch on the nape, and, connected with this, a yellow ring round the snout; ventrals and subcaudals brown or black, edged with white.
Total length, 415 millimetres; tail 45.
Habitat: Queensland.
(5) P. diadema ([fig. 46]).—Nasal shield entire, widely separated from the præocular; 2 + 2 temporals; third and fourth upper labials entering the eye; 164-203 ventrals; 40-62 subcaudals. Colour pale brown or reddish, with a brown edging to each scale forming a reticulate pattern; a yellow cross-band on the occiput; belly uniformly white.
Total length, 600 millimetres; tail 80.
Habitat: Eastern, Northern, and Western Australia.
(6) P. warro.—Characters the same as in the previous species; 143 ventrals. Colour brown; a broad lunate black collar on the nape; head black above, but paler than the collar.
Habitat: Port Curtis, Queensland.
(7) P. sutherlandi.—Characters as before. Scales on the body in 17 rows; 160 ventrals; 40 subcaudals. Colour red-brown on the back, yellow on the belly; a broad lunate black collar on the nape, with a lighter edging; light bars across the head, body, and tail.
Habitat: Norman River, Queensland.
(d) Diemenia.
Fig. 47.—Diemenia psammophis.
Fig. 48.—Diemenia olivacea. (Northern Australia and New Guinea).
(After Krefft.)
Fig. 49.—Diemenia textilis.
Maxillary bones extending forwards as far as the palatines, with a pair of large grooved poison-fangs, followed, after an interspace, by 7-15 small grooved teeth; anterior mandibular teeth much elongated, resembling poison-fangs. Head scarcely distinct from the neck; eyes rather large, with round pupils; nasal shield entire or divided; frontal elongate.
Body cylindrical; scales smooth, in 15-19 rows (more on the neck). Tail moderate or long; subcaudals all or for the most part in 2 rows.
Coloration very variable, orange-yellow, olive, red-brown, or pale brown.
Average length, 1,000-1,700 millimetres.
Habitat: South-eastern New Guinea, and Australia.
Seven species of this genus are known, divided into two groups as follows:—
(1) Scales on the body in 15 rows.
D. psammophis. ([fig. 47]).—Internasal shields at least half as long as the præfrontals.
D. torquata.—Internasals more than half as long as the præfrontals.
D. olivacea. ([fig. 48]).—Internasals not more than half as long as the præfrontals; snout broad.
Fig. 50.—Diemenia nuchalis.
(2) Scales in 17 or 19 rows.
D. modesta.—154-165 ventrals.
D. textilis (Brown Snake, [fig. 49]).—190-232 ventrals.
D. nuchalis ([fig. 50]).—184-224 ventrals.
(e) Pseudechis.
Maxillary bones extending forwards as far as the palatines, with a pair of large grooved poison-fangs followed by 2-5 small solid teeth; anterior mandibular teeth long. Head distinct from the neck; eyes rather small, with round pupils; nostril between two nasal shields. Body cylindrical. Scales smooth, in 17-23 rows (more on the neck). Tail moderate; subcaudals in 2 rows, or partly single, partly in 2 rows.
Fig. 51.—Pseudechis porphyriacus.
Total length, 1,500-2,000 millimetres, sometimes more.
Habitat: Australia and New Guinea.
This genus includes eight species.
(1) P. porphyriacus (Black Snake; [fig. 51]).—Frontal shield longer than broad; 180-200 ventrals; 50-60 subcaudals.
Colour black on the back; outer row of scales red at the base; ventrals red, edged with black.
(2) P. cupreus.—199-210 ventrals; 57-72 subcaudals.
Colour coppery above, brown or orange below, all the scales and shields edged with brown.
(3) P. australis.—199-220 ventrals; 57-70 subcaudals; frontal shield once and two-thirds to twice as long as broad.
Colour pale brown on the back, yellowish on the belly.
(4) P. darwiniensis.—Frontal as broad as long; 212 ventrals; 54-64 subcaudals.
Colour reddish-brown; head pale brown; belly yellowish-white.
(5) P. papuanus.—Scales in 19-21 rows (26 or 27 on the neck); 221-224 ventrals; 49-55 subcaudals.
Colour uniform black; chin white.
(6) P. scutellatus.—Subcaudal shields in 2 rows; scales on the body in 23 rows (25-30 on the neck); 230-233 ventrals; 61-78 subcaudals.
Colour pale brown or dark brown; snout and cheeks pale brown or yellowish; belly yellow.
(7) P. microlepidotus.—30-36 scales across the neck, 23 across the middle of the body; 232-237 ventrals; 61-66 pairs of subcaudals.
Colour dark brown on the back, yellowish-grey on the belly; head sometimes blackish.
(8) P. ferox.—Snout very broadly rounded. Scales on the body in 23 rows; 235 ventrals; 60 pairs of subcaudals.
Colour black above, yellowish beneath.
(f) Denisonia.
Maxillary bones prolonged as far as the palatines, with a pair of large grooved poison-fangs, followed by 3-5 small solid teeth; anterior mandibular teeth greatly developed. Head fairly distinct from the body; eyes small, with round or vertically elliptic pupils; nasal shield entire or divided. Body cylindrical; scales smooth, in 15-19 rows; tail moderate or short; subcaudals in a single row, except in one species.
According to the British Museum Catalogue, the genus Denisonia includes twenty-one species, the principal characters of which are as follows:—
Fig. 52.—Denisonia superba (The Copperhead).
(1) D. superba (The Copperhead. Fig. 52).—Scales in 15-17 rows; nasal shield entire, in contact with the præocular; ventral scales 145-160; subcaudals 41-50.
Colour brownish to dark olive on the back, often yellow or salmon-red on the sides; belly yellowish or greyish-olive.
Total length, 1,010 millimetres; tail 160.
Habitat: New South Wales, Southern Australia, Tasmania.
(2) D. coronata.—Scales in 15 rows; 138-151 ventrals; 38-51 subcaudals.
Fig. 53.—Denisonia coronoides.
Colour olive, with a black streak on each side of the head; belly yellowish or pale olive.
Total length, 480 millimetres; tail 95.
Habitat: Western Australia and New South Wales.
(3) D. coronoides ([fig. 53]).—Scales in 15 rows; 136-151 ventrals; 39-57 subcaudals.
Colour brown, lips yellow; belly salmon-red to dark olive-grey; end of tail salmon-red.
Total length, 440 millimetres; tail 80.
Habitat: Southern Australia and Tasmania.
(4) D. muelleri.—Scales in 17 rows; 118 ventrals; 38 subcaudals.
Colour grey-brown; lips and chin with yellow spots; belly grey.
Total length, 292 millimetres; tail 52.
Habitat: Queensland.
(5) D. frenata.—Scales in 19 rows; 167 ventrals; 35 subcaudals.
Colour olive-brown; upper lip yellow; belly white.
Total length, 390 millimetres; tail 54.
Habitat: Lake Elphinstone, Queensland.
(6) D. ramsayi ([fig. 54]).—Scales in 15 rows; 164 ventrals; 51 subcaudals.
Fig. 54.—Denisonia ramsayi.
Colour dark olive-green above, yellow beneath; subcaudals nearly black.
Total length, 265 millimetres; tail 50.
Habitat: New South Wales.
(7) D. signata ([fig. 55]).—Scales in 17 rows; 153-170 ventrals; 41-56 subcaudals.
Fig. 55.—Denisonia signata.
Colour dark olive or black, head brown; belly dark grey or black.
Total length, 640 millimetres; tail 120.
Habitat: Queensland, New South Wales.
(8) D. daemelii.—Scales in 17 rows; 147-168 ventrals; 33-45 subcaudals.
Colour olive, head darker; belly yellowish-white.
Total length, 380 millimetres; tail 60.
Habitat: Queensland.
(9) D. suta.—Scales in 19 rows; 157-164 ventrals; 25-30 subcaudals.
Colour pale olive-brown, head dark brown, nape black; upper lip and belly yellow.
Total length, 200 millimetres; tail 23.
Habitat: Southern Australia.
(10) D. frontalis.—Scales in 19 rows; 154 ventrals; 30 subcaudals.
Colour light brown, with a vertebral black line; belly pearly-white, with a median bronze-coloured band.
Total length, 400 millimetres; tail 50.
Habitat: New South Wales.
(11) D. flagellum.—Scales in 17 rows; 132-138 ventrals; 25-27 subcaudals.
Colour pale brown; vertex, occiput, and nape black; upper lip and belly white.
Total length, 380 millimetres; tail 40.
Habitat: Victoria.
(12) D. maculata. ([fig. 56]).—Scales in 17 rows; 121-136 ventrals; 20-30 subcaudals.
Fig. 56.—Denisonia maculata.
Colour dark grey-brown, or brown; a large dark olive-green or brown blotch on the head, with two or three unequal light grey spots; belly white.
Total length, 400 millimetres; tail 55.
Habitat: Queensland.
(13) D. punctata.—Scales in 15 rows; 160 ventrals; 25 subcaudals.
Colour pale brown; head and nape orange; upper lip and belly yellow.
Total length, 350 millimetres; tail 36.
Habitat: North-Western Australia.
(14) D. gouldii ([fig. 57]).—Scales in 15 rows; 140-170 ventrals; 22-23 subcaudals.
Fig. 57.—Denisonia gouldii.
Colour brownish-yellow; nape black; head covered with a broad greenish-blue blotch, extending from the nose to the neck; upper lip and belly yellow.
Total length, 435 millimetres; tail 50.
Habitat: Western and Southern Australia.
(15) D. nigrescens.—Scales in 15 rows; 170-200 ventrals; 30-46 subcaudals.
Colour dark olive; head black; belly yellow.
Total length, 545 millimetres; tail 75.
Habitat: New South Wales and Queensland.
(16) D. nigrostriata.—Scales in 15 rows; 180-184 ventrals; 50-64 subcaudals.
Colour yellow, streaked with black; head dark brown; upper lip and belly yellowish-white.
Total length, 380 millimetres; tail 52.
Habitat: Queensland.
(17) D. carpentariæ.—Scales in 15 rows; 166-183 ventrals; 31-43 subcaudals.
Colour brown; upper lip and belly yellowish-white.
Total length, 285 millimetres; tail 47.
Habitat: Northern Queensland.
(18) D. pallidiceps.—Scales in 15 rows; 170-178 ventrals; 37-38 subcaudals.
Colour dark olive-brown; head somewhat paler; belly yellowish. Total length, 590 millimetres; tail 80.
Habitat: Northern Australia.
(19) D. melanura.—Scales in 15 or 17 rows; 165-171 ventrals; 38-48 subcaudals.
Colour dark brown; head and sides usually reddish; belly yellow; tail black.
Total length, 1,000 millimetres; tail 140.
Habitat: Solomon Islands.
(20) D. par.—Scales in 16 rows; 164-166 ventrals; 40-49 subcaudals.
Colour reddish-brown, in broad bands with white intervals; head blackish-brown; belly white; tail with red rings.
Total length, 750 millimetres; tail 110.
Habitat: Faro and Howla Islands, Bougainville Straits, Solomon Islands.
(21) D. woodfordii.—Scales in 17 rows; 166-172 ventrals; 41-45 subcaudal pairs.
Colour brownish-white, with a reticulate pattern; head dark brown; belly white.
Total length, 670 millimetres; tail 100.
Habitat: New Georgia, Solomon Islands.
(g) Micropechis.
Maxillary bones extending forward as far as the palatines, with a pair of large grooved poison-fangs, followed by three small solid teeth; mandibular teeth longer in front. Head distinct from the neck; eyes very small, with round pupils; nostril between two nasal shields. Body cylindrical; scales smooth, in 15 or 17 rows. Tail short; subcaudals in 2 rows.
(1) M. ikaheka.—Scales in 15 rows; 180-223 ventrals; 39-55 subcaudals.
Colour yellow and black, in irregular cross-bars; head and tail black above; belly yellow.
Total length, 1,550 millimetres; tail 180.
Habitat: New Guinea.
(2) M. elapoides.—Scales in 17 rows; 208 ventrals; 35 subcaudals.
Colour cream, with 22 black bands, broader than the interspaces between them; snout and ocular region black.
Total length, 750 millimetres; tail 75.
Habitat: Florida Island, Solomon Group.
(h) Hoplocephalus.
Characters the same as in Micropechis. Scales in 21 rows; ventrals angulate and notched laterally. Tail moderate; subcaudals in a single row.
(1) H. bungaroides (Syn. H. variegatus. The Broad-headed Snake).—204-221 ventrals; 40-56 subcaudals.
Colour black on the back, with yellow spots forming more or less regular cross-bands on the body; upper lip yellow, margined with black; belly blackish, yellow on the sides.
Total length, 1,620 millimetres; tail 210.
Habitat: New South Wales.
(2) H. bitorquatus ([fig. 58]).—Ventral scales strongly angulate laterally, 191-227; subcaudals 44-59.
Fig. 58.—Hoplocephalus bitorquatus.
Colour olive-green; head pale olive, with a bright yellow occipital blotch, and a large black blotch on each side of the nape; a pair of small spots in front of and between the eyes; three black transverse blotches on the vertex; belly greyish-olive or brown.
Total length, 510 millimetres; tail 95.
Habitat: Queensland, New South Wales.
(3) H. stephensii.—239 ventrals; 60 subcaudals.
Body barred alternately with black and white; the black bars are twice as broad as the white ones; head dark, spotted with yellow; a W-shaped yellow mark on the back of the head.
Total length, 760 millimetres.
Habitat: Port Macquarie, New South Wales.
(i) Tropidechis.
Same general characters; nasal shield entire; scales on the body strongly keeled, in 23 rows. Tail moderate; subcaudals in a single row.
T. carinatus.—Colour dark olive, with darker cross-bands; belly yellow, more or less tinged with olive-green.
Total length, 730 millimetres; tail 120.
Habitat: New South Wales, Queensland.
(j) Notechis.
Same general characters; pupil round; nasal shield entire. Body cylindrical; scales smooth, disposed obliquely, in 15-19 rows, the lateral scales shorter than the dorsals. Tail moderate; subcaudals in a single row.
N. scutatus (Syn. Hoplocephalus curtus. The Tiger Snake. Fig. 59).—Colour dark olive; belly yellow or olive; the shields often dark-edged.
Fig. 59.—Notechis scutatus (The Tiger Snake.)
Total length, 1,280 millimetres; tail 170.
Habitat: Australia and Tasmania.
(k) Rhinhoplocephalus.
Dentition as in Hoplocephalus. Head but little distinct from the neck; eyes small, with round pupils; no internasal shields. Body cylindrical, rigid. Scales smooth, in 15 rows. Tail short; subcaudals in a single row.
R. bicolor.—Colour greyish-olive on the back, yellowish-white on the belly; tongue white.
Total length, 395 millimetres; tail 55.
Habitat: Australia.
(l) Brachyaspis.
Characters the same, but head distinct from the neck; eyes small, with vertically elliptic pupils; nostril between two nasal shields. Body stout, cylindrical; scales smooth, slightly oblique, in 19 rows. Tail short; subcaudals in a single row.
B. curta.—Colour uniform olive-brown; belly yellowish.
Total length, 490 millimetres; tail 70.
Habitat: Western Australia.
(m) Acanthophis (Death Adder).
([Figs. 60], [61].)
Maxillary bones extending forwards as far as the palatines, with a pair of large grooved poison-fangs, followed by two or three small teeth; anterior mandibular teeth elongate, fang-like. Head distinct from the neck; eyes small, with vertically elliptic pupils; nostril in the upper part of a single nasal shield. Body stout, cylindrical. Scales more or less distinctly keeled, in 21-23 rows. Tail short, compressed at the end and terminating in a sort of long spine, turned upwards; anterior subcaudals in a single row, posterior in 2 rows.
Fig. 60.—Skull of Acanthophis antarcticus. (After G. A. Boulenger, op. cit.)
A. antarcticus (The Death Adder; [fig. 61]).—Supraocular shields often raised and angular, assuming the shape of little horns; scales on the crown of the head rugose and striated; 113-130 ventrals; 41-51 subcaudals (the last 5-27 are divided).
Colour yellow-brown or reddish, with more or less distinct dark cross-bands; black spots or small dark bars on the lips; belly yellowish-white; end of tail yellow or black, covered with spiny scales.
Fig. 61.—Acanthophis antarcticus (The Death Adder).
Total length, 850 millimetres; tail 150.
Habitat: Moluccas, New Guinea, Australia.
(n) Elapognathus.
Maxillary bones extending forwards as far as the palatines, with a pair of moderately large grooved poison-fangs; no other maxillary teeth; mandibular teeth subequal. Eyes moderate, with round pupils; nasal shield entire. Body cylindrical; scales smooth, in 15 rows; ventrals rounded; tail moderate; subcaudals in a single row.
E. minor.—Colour dark olive, with a black occipital blotch in the young; belly yellow or greenish-grey.
Total length, 460 millimetres; tail 95.
Habitat: South-west Australia.
(o) Rhynchelaps.
Maxillary bones extending forwards as far as the palatines, with a pair of moderately large grooved poison-fangs, and two small teeth near the posterior extremity of the bone; anterior mandibular teeth the longest. Head small, not distinct from the neck; eyes small, with vertically elliptic pupils; nostril in a single nasal shield. Body short, cylindrical; scales smooth, in 15-17 rows. Tail very short; subcaudals in 2 rows.
(1) R. bertholdi.—Scales in 15 rows; 112-126 ventrals.
Colour yellow, with 19-40 black annuli, usually narrower than the interspaces; head brown, with a large black blotch on the nape, and another on the vertex and temples.
Total length, 270 millimetres; tail 22.
Habitat: Southern and Western Australia.
(2) R. australis ([fig. 62]).—Scales in 17 rows; 152-163 ventrals; 18-20 subcaudals.
Fig. 62.—Rhynchelaps australis.
Colour red on the body, with ill-defined cross-bars formed of yellowish black-edged scales; a black blotch on the head, covering the vertex and temples, and surrounding the eyes; another large blotch on the nape; snout and occiput yellow; belly white.
Total length, 290 millimetres; tail 25.
Habitat: Queensland.
(3) R. semifasciatus.—Scales in 17 rows; 143-170 ventrals; 17-25 subcaudals.
Colour yellow, with brown cross-bands; large brown blotches on the head and nape; belly white.
Total length, 300 millimetres; tail 30.
Habitat: West Australia.
(4) R. fasciolatus.—Scales in 17 rows; 145-161 ventrals; 22-27 subcaudals.
Colour red, with numerous blackish-brown cross-bands; large blackish-brown blotches on the head and nape; belly white.
Total length, 335 millimetres; tail 30.
Habitat: West Australia.
(p) Furina.
([Figs. 63] and [64].)
Maxillary bones extending forwards beyond the palatines, bearing a pair of moderately large grooved poison-fangs, and one or two small teeth near their posterior extremities; mandibular teeth subequal. Head small, not distinct from neck; eyes very small, with round pupils; nostril in a single nasal shield. Body cylindrical; scales smooth, in 15 rows. Tail very short, obtuse; subcaudals in 2 rows.
(1) F. calonota.—Six supralabial shields; 126-131 ventrals; 29-30 subcaudals.
Colour yellow, with a black vertebral stripe; a black bar across the end of the snout; a large black blotch covering the vertex and the parietals; belly white.
Total length, 215 millimetres; tail 33.
Habitat: West Australia.
(2) F. bimaculata.—Scales in 15 rows; 181-200 ventrals; 21-25 subcaudals.
Fig. 63.—Skull of Furina occipitalis. (After G. A. Boulenger, op. cit.)
Fig. 64.—Furina occipitalis.
Colour yellow, with large black blotches on the snout, middle of head, and occiput; belly white.
Total length, 330 millimetres; tail 25.
Habitat: West Australia.
(3) F. occipitalis ([fig. 64]).—Scales in 15 rows; 180-234 ventrals; 14-25 subcaudals.
Entire body ringed with black and white, annuli narrower on belly; head black, with a broad white band across the occiput, and another narrower and irregular one across the snout; nose black.
Total length, 590 millimetres; tail 36.
Habitat: Australia.
There are no poisonous snakes in New Zealand. In New Caledonia no terrestrial poisonous snakes are known, but Hydrophiidæ abound on its shores, as on those of the majority of the islands of the Pacific.
In Australia, especially in New South Wales and farther to the north, fatalities due to the bites of poisonous snakes are not rare. The most dangerous species are: Acanthophis antarcticus (the Death Adder), Diemenia textilis (the Brown Snake), Pseudechis porphyriacus (the Black Snake), and Notechis scutatus or Hoplocephalus curtus (the Tiger Snake).
The health authorities of this country have accordingly taken the wise precaution of circulating very widely among the public coloured placards bearing illustrations of these four species, with a description of the essential anatomical details by which they may be recognised. Similar placards are exhibited in all the schools, and a generous distribution is made of instructions, printed on handkerchiefs, indicating the most effective method of treating poisonous bites.
In Queensland, according to information furnished to me by Mr. C. W. De Vis, late Director of the Queensland Museum, Brisbane, the number of deaths resulting from the bites of poisonous snakes has been only twenty-seven in ten years.
E.—AMERICA.
The fauna of the New World includes only a very small number of poisonous snakes belonging to the family Colubridæ. The Genus Elaps alone is represented there by twenty-eight species, scattered over Mexico, Central America, Bolivia, Ecuador, Peru, Colombia, and Brazil.
Viperidæ, on the other hand, are extremely numerous, and belong exclusively to the subfamily Crotalinæ; there are no Viperinæ.
I.—COLUBRIDÆ.
(a) Elaps.
([Fig. 65].)
Fig. 65.—Skull of Elaps marcgravii. (After G. A. Boulenger, op. cit.)
The characters of this genus are: Maxillary bones very short, extending beyond the palatines, and bearing a pair of large poison-fangs; pterygoid teeth few or absent; mandibular teeth all of equal length. No postfrontal bones; præfrontals meeting, or narrowly separated on the median line. Head small, not distinct from neck; eyes small, with vertically elliptic or sub-elliptic pupils; nostril between two nasal shields. Body cylindrical; scales smooth, in 15 rows. Tail short; subcaudal scales in 2 rows, or partly single, partly in 2 rows.
(1) E. surinamensis.—Seven supralabials, of which the fourth enters the eye; frontal shield very narrow; 167-182 ventrals.
Colour red, with black annuli disposed in threes (the middle one broader), separated by narrow yellow interspaces; 7 or 8 sets of annuli on the body; the red scales dotted with black; head red above, with the shields black-edged, followed by a black cross-band behind the parietals.
Total length, 740 millimetres; tail 95. Grows to 1,900 millimetres.
Habitat: Venezuela, Guianas, Northern Brazil, North-east Peru.
(2) E. heterochilus.—Six supralabials, second and third entering the eye; snout narrow; 209 ventrals.
Colour red, with black annuli, as in E. marcgravii.
Total length, 553 millimetres; tail 43.
Habitat: Brazil.
(3) E. euryxanthus (Sonoran Coral Snake).—Seven supralabials, third and fourth entering the eye; internasals nearly as long as the præfrontals; 215-241 ventrals; 21-29 subcaudals.
Colour red, with 11 black annuli edged with yellow; head black.
Total length, 400 millimetres; tail 33.
Habitat: Arizona, Colorado, North-western Mexico. It is found in Arizona up to an altitude of nearly 6,000 feet (1,800 metres).
(4) E. gravenhorstii.—First lower labial in contact with its fellow; posterior nasal not reaching the præocular: 191 ventrals; 23 subcaudals.
Colour: Seven sets of black annuli disposed in threes, median annulus the broadest; head black, with a yellow transverse band behind the eyes.
Total length, 550 millimetres; tail 50.
Habitat: Brazil.
(5) E. langsdorffii.—Ventrals 204-225; subcaudals 37-54; 1 + 1 temporals.
Colour dark brown, with 63 transverse series of cream-coloured spots, each occupying one scale; belly yellow, with red cross-bands.
Total length, 300 millimetres.
Habitat: Upper Amazons.
(6) E. buckleyi.—203-211 ventrals; 39-43 subcaudals; 1 + 2 temporals.
Colour orange, with 48-60 black annuli edged with small yellow spots; head black; temples yellow.
Total length, 505 millimetres; tail 70.
Habitat: Northern Brazil, Eastern Ecuador.
(7) E. anomalus.—227 ventrals; 29 subcaudals; 1 + 1 temporals.
Colour: Body with 55 black annuli separated by narrow brownish-white bands; belly yellowish; anterior half of head black, posterior half yellow; tail yellow or red, with 4 black rings.
Total length, 280 millimetres; tail 23.
Habitat: Colombia.
(8) E. heterozonus.—Scales in 15 rows; 210-219 ventrals; 16-23 subcaudals; 1 + 1 temporals.
Colour red or brown, with 17 to 23 black rings, mostly narrower than the interspaces; a black band on the head across the eyes.
Total length, 900 millimetres; tail 40.
Habitat: Eastern Ecuador, Eastern Peru, Bolivia.
(9) E. elegans.—Scales in 15 rows; 189-221 ventrals; 29-47 subcaudals; 1 + 1 temporals.
Colour: Black annuli in sets of three, separated by reddish-brown interspaces; 12-17 sets; head black, with yellow blotches.
Total length, 730 millimetres; tail 70.
Habitat: Mexico and Guatemala.
(10) E. annellatus.—Scales in 15 rows; 200-211 ventrals; 30-45 subcaudals; 1 + 1 temporals.
Colour black, with 41-49 narrow white rings on the body, 4-7 on the tail; a white ring on the head.
Total length, 490 millimetres; tail 70.
Habitat: Eastern Peru.
(11) E. decoratus.—Scales in 15 rows; 196-213 ventrals: 29-37 subcaudals.
Colour red, with 15-16 sets of black annuli disposed in threes; head yellow, with end of snout black, and a black band across the eyes.
Total length, 625 millimetres.
Habitat: Brazil.
(12) E. dumerilii.—Scales in 15 rows; 197-204 ventrals; 50-53 subcaudals.
Colour: 8-9 sets of three black annuli on red and yellow; head black, with a yellow band on the occiput.
Total length, 410 millimetres; tail 65.
Habitat: Colombia.
(13) E. corallinus (The Coral Snake).—Scales in 15 rows; 179-231 ventrals; 30-47 subcaudals; 1 + 1 temporals.
Colour: Body with black annuli, separated by red interspaces edged with yellow; head bluish-black; temples yellow; a blue line from behind the eye to the lower jaw; tail white.
Total length, 790 millimetres; tail 70.
Habitat: Tropical South America and Lesser Antilles (St. Thomas, St. Vincent, Martinique).
(14) E. hemprichii.—Scales in 15 rows; 168-181 ventrals; 22-29 subcaudals; 1 + 1 temporals.
Colour: Black, with red or yellow annuli, a broad annulus between the narrow ones; occiput, upper lip, and temples yellow.
Total length, 720 millimetres; tail 65.
Habitat: Guianas, Colombia, Peru.
(15) E. tschudii.—Scales in 15 rows; 207-221 ventrals; 21-28 subcaudals.
Colour: Body with black annuli broader than the interspaces, disposed in sets; interspaces red and yellow; snout and occiput black.
Fig. 66.—Elaps fulvius (The Harlequin Snake, or Coral Snake). (After L. Stejneger.)
Total length, 430 millimetres; tail 35.
Habitat: Peru.
(16) E. dissoleucus.—Scales in 15 rows; 200 ventrals; 19 subcaudals.
Coloration as in foregoing species.
Total length, 1,070 millimetres; tail 35.
Habitat: Venezuela.
(17) E. fulvius (Harlequin, or Coral Snake, [fig. 66]).—Scales in 15 rows; 180-237 ventrals; 30-59 subcaudals.
Colour: Body with black, red, and yellow annuli; tail with black and yellow annuli; snout black.
Total length, 990 millimetres; tail 85.
Habitat: Eastern North America, from Southern Virginia, the Ohio River, and the Missouri to the Rio Grande, Mexico. Central America.
(18) E. psyches.—Scales in 15 rows; 188-214 ventrals; 32-47 subcaudals.
Colour: Body with alternate black and brown annuli, and 48-52 narrow yellow rings; head black, blotched with yellow.
Total length, 495 millimetres; tail 80.
Habitat: Guianas.
(19) E. spixii.—Scales in 15 rows; 201-219 ventrals; 22-29 subcaudals.
Colour: red, with 20-38 black rings disposed in threes; a black occipital collar, followed by a wide red space.
Total length, 1,400 millimetres; tail 70.
Habitat: Venezuela and Northern Brazil.
(20) E. frontalis.—Scales in 15 rows; 197-230 ventrals; 15-26 subcaudals. Tail ending very obtusely.
Colour: Body with black annuli disposed in threes, with red and yellow interspaces; head black, spotted with yellow or red.
Total length, 1,350 millimetres; tail 70.
Habitat: Southern Brazil, Uruguay, Paraguay, Argentina.
(21) E. marcgravii.—Scales in 15 rows; 210-240 ventrals; 23-42 subcaudals.
Colour: Body with black annuli in 6-10 sets of three, separated by broad red interspaces, the middle annulus usually wider; snout yellow, the end usually black; back of head red.
Total length, 1,120 millimetres; tail 100.
Habitat: Tropical South America.
(22) E. lemniscatus.—Scales in 15 rows; 241-262 ventrals; 30-39 subcaudals.
Colour: Body with 11-14 sets of black annuli disposed in threes, separated by red interspaces; head yellow; end of snout and a band across the middle of the head black.
Total length, 1,000 millimetres; tail 80.
Habitat: Guianas, Brazil.
(23) E. filiformis.—Scales in 15 rows; 290-308 ventrals; 35-45 subcaudals.
Colour: Body with black annuli disposed in threes, with red interspaces; head yellow; end of snout black; a black band across the eyes.
Total length, 575 millimetres; tail 40.
Habitat: Amazons, Colombia.
(24) E. mipartitus.—Scales in 15 rows; 210-278 ventrals; 24-34 subcaudals.
Colour: black, with 40-68 narrow white annuli; head black to between the eyes, elsewhere yellow.
Total length, 610 millimetres; tail 50.
Habitat: Central America and Tropical South America.
(25) E. fraseri.—Scales in 15 rows; 303 ventrals; 25 subcaudals.
Colour: black, with 75 narrow whitish rings with broken outlines; head black in front, yellow behind.
Total length, 780 millimetres; tail 40.
Habitat: Ecuador.
(26) E. mentalis.—Scales in 15 rows; 255-268 ventrals; 30-31 subcaudals.
Colour: Body black, with 58-70 narrow white annuli, which become wider on the belly; snout black, occiput yellow; tail annulate, black and orange.
Total length, 490 millimetres; tail 30.
Habitat.—Colombia and Ecuador.
(27) E. ancoralis.—Scales in 15 rows; 258 ventrals; 31 subcaudals.
Colour: Body with 16 sets of black annuli disposed in threes, the middle one of each set a little wider; head light in front, spotted with black; an anchor-shaped black mark on the occiput and nape.
Total length, 780 millimetres; tail 57.
Habitat: Ecuador.
(28) E. narduccii.—Scales in 15 rows; 240-315 ventrals; 15-33 subcaudals.
Colour: black, beneath with yellow or red cross-bands or transversely oval spots, sometimes extending as triangular blotches up the sides; head with a yellow cross-band.
Total length, 720 millimetres; tail 50.
Habitat: Eastern Ecuador, North-eastern Peru, Bolivia.
The species of the genus Elaps, which are remarkable for the brightness and beauty of their colours, are generally found in forests.
“The traveller,” says Neuwied, “who ventures into the great Brazilian forests, where the ground is covered with leafy plants, is astonished to see shining through the verdure the black and red rings of the beautiful Coral Snake. Uncertainty as to whether the creature is dangerous alone prevents him from seizing it. The body of the snake is not lithe enough to enable it to climb trees. Its food consists of small animals.”
Dr. Lacerda relates that the Austrian naturalist Wertheimer, when in the Brazilian settlement of Philadelphia, was bitten by a Coral Snake in the back of the hand. The usual symptoms of poisoning manifested themselves immediately, and the unfortunate man died twelve hours later. Nevertheless, the small size and slenderness of the fangs, the narrowness of their canals, and the considerable distance between the fangs and the anterior opening of the mouth, must necessarily render the bites of these snakes less serious and of rarer occurrence.
II.—VIPERIDÆ.—CROTALINÆ.
The Solenoglypha are infinitely more formidable in the two divisions of the New World. They are represented by a large number of species, some of which are feared in consequence of their size and ferocity, even more than on account of the deadliness of their venom ([fig. 67]).
Fig. 67.—Head and Skull of Crotalus horridus.
The American Crotalinæ are divided into two groups:—
The first of these comprises snakes not provided with the caudal appendage, which is characteristic of the Rattle-Snakes. It consists of two genera:—
(a) Ancistrodon.
(b) Lachesis.
The second group includes only those snakes the tails of which are terminated by the scaly appendage known as the “rattle.”
These are likewise divided into two genera:—
(c) Sistrurus.
(d) Crotalus.
(a) Ancistrodon.
Usually with 9 shields on the head, or internasals and præfrontals broken up into scales. Body cylindrical: scales smooth or keeled, with apical pits. Tail moderate or short; subcaudals single or in 2 rows.
Fig. 68.—Ancistrodon piscivorus (Water Viper). (After Stejneger.)
(1) A. piscivorus (Water Viper, or Cotton-mouth; [fig. 68]).—Snout rounded, soft above. Scales on the body strongly keeled, in 25 (rarely 27) rows; 130-147 ventrals; 33-51 subcaudals, all single or the posterior divided.
Colour pale reddish-brown to dark brown above, with more or less distinct dark brown cross-bands, or with alternating C-shaped dark markings each enclosing a central spot. Belly dull yellow spotted with black, or almost black.
Total length, 1,170 millimetres; tail 200.
Habitat: Eastern North America, from North Carolina and Indiana to Florida and Texas. The Water Viper lives for the most part in the vicinity of rivers, and feeds upon fish, but also devours small warm-blooded animals. The Creoles call it the Congo Snake. It is fairly common in the environs of New Orleans. In summer time it conceals itself in the branches of trees at the edge of the water. It frequents inundated rice-fields, and is a terror to the blacks. It attacks readily, and opens its jaws some seconds before it bites.
(2) A. bilineatus.—Snout obtusely pointed. Scales more or less strongly keeled, in 23 (rarely 25) rows; 135-141 ventrals; 52-64 subcaudals, anterior single, posterior divided.
Colour dull yellow or reddish-brown, with more or less distinct darker cross-bands, or alternating transverse blotches, with yellow edges; a vertical yellow line on the rostral shield, and a fine yellow line round the snout; belly brownish or blackish, with white spots.
Total length, 1,100 millimetres; tail 200.
Habitat: Mexico, Guatemala, Honduras.
(3) A. contortrix (The Copperhead).—Snout rounded or truncate. Scales strongly keeled, in 23 (rarely 25) rows; 145-155 ventrals; 31-52 subcaudals, anterior single, posterior divided.
Colour dull yellow or reddish-brown, with dark brown or brick-red cross-bars; these bars are sometimes interrupted on the vertebral line, and form alternating triangles; belly yellow or reddish, more or less spotted with grey or brown.
Total length, 990 millimetres; tail 110.
Habitat: North America, from Massachusetts and Kansas to Northern Florida and Texas.
This snake is often more dreaded than a Rattle-Snake.
(b) Lachesis.
In Lachesis the caudal rattle is represented by a series of 10 or 12 rows of spiny scales, which are slightly hooked at the tips. The head is covered with small shields or smooth or keeled scales, with or without apical pits. The maxillary is much reduced; the transverse or pterygoid bone, on the contrary, is greatly developed.
The name is derived from one of the Parcæ, daughters of Night, who placed the thread on the spindle, and upon whom depended the fate of men.
In addition to the 19 Asiatic species, of which we have already given descriptions, the genus Lachesis includes 21 American species.
(1) L. mutus (Bushmaster, or Surucucu).—Two or three scales separating the internasals in front; 10 to 15 scales on a line between the supraoculars; 9 or 10 supralabials. Scales tubercularly keeled, feebly imbricate, in 35 or 37 rows; 200-230 ventrals; 32-50 subcaudals.
Fig. 69.—Lachesis lanceolatus (Fer-de-lance of Martinique). (After Stejneger.)
Colour yellow or pinkish on the back, with a series of large rhomboidal brown or black spots enclosing smaller light spots; a black streak from the eye to the angle of the mouth.
Total length, 1,995 millimetres; tail 170.
Habitat: Central and Tropical South America.
(2) L. lanceolatus (known as the Fer-de-lance in Martinique, and Jararacussu in Brazil; [fig. 69]).—Snout obtuse, slightly turned up; upper head-scales small, imbricate, more or less strongly keeled, in 5-10 longitudinal series between the supraoculars, which are large; 7 or 8 supralabials. Scales in 23-33 rows, sharply keeled; 180-240 ventrals; 46-70 subcaudals, all or the greater part in two rows.
Coloration very variable, grey, brown, yellow, olive, or reddish; uniform or with more or less distinct dark spots, or cross-bands, or with dark triangles on the sides enclosing pale rhombs; a dark streak from the eye to the angle of the mouth; belly yellowish, uniform, or spotted with brown.
Total length, 1,600 millimetres; tail 190.
Habitat: Tropical America; Mexico, Martinique, St. Lucia, Bequia Island near St. Vincent, Venezuela, Guianas, Rio de Janeiro.
This snake does not exist in Guadeloupe. “In the islands in which it is found,” says Dr. Rufz de Lavison, “its presence makes itself felt even where man has built his dwelling and cultivates the soil. Because of it no one can carelessly lie down to rest in the shade of a tree; no one can walk in the woods or enter unconcernedly into the pleasures of the chase.” It is especially abundant in coffee and sugar plantations, and is met with from the sea-level up to the summits of the highest mountains in Martinique and St. Lucia. It not infrequently makes its way into human habitations, and is not uncommon in gardens, even entering those of the town of Fort-de-France.
It does not seek its prey by day, but remains on the alert, always ready to bite. With open mouth, and fangs projecting forwards, it strikes with the rapidity of lightning. It swims in the rivers and moves over the ground with great speed. Oviposition takes place in July, and the young are hatched forthwith, the usual number being from about 50-60.
It feeds upon lizards and rats, but also destroys a certain number of fowls and turkeys. All the large animals are afraid of it. Its bite is extremely dangerous, and causes about a hundred deaths in Martinique every year.
In striking at its prey or at a man, the Fer-de-lance throws back its head and opens its jaws widely, with the fangs directed forwards. It drives in its poison-teeth as with the blow of a hammer, and quickly draws back again. When very excited, it resumes its position and strikes afresh. It never becomes tame, but is capable of living a fairly long time in captivity. I have kept a number of specimens of it for more than two years, caged in my laboratory.
(3) L. atrox (Labaria).—Closely resembling L. lanceolatus, but bulkier; the enormous head is armed with powerful fangs, which are often more than a centimetre in length; 7 supralabial shields; scales in 25-29 rows, strongly keeled; 161-216 ventrals; 47-73 pairs of subcaudals.
Colour brown, with dark cross-bands or triangular blotches, with the apices adjacent on the vertebral line; a dark streak from the eye to the angle of the mouth; belly yellowish-white, speckled with brown, or brown spotted with yellowish-white.
Total length, 1,110 millimetres; tail 180.
Habitat: from Central America to Peru and Northern Brazil.
(4) L. pulcher.—Two postocular shields and a subocular, separated from the labials by one series of scales; 7 supralabials; scales in 21 or 23 rows, strongly and tubercularly keeled; 156-172 ventrals; 58-64 pairs of subcaudals.
Colour olive-grey, with brown, light-edged cross-bands, which are continuous or broken on the vertebral line; a light streak from the eye to the angle of the mouth; belly covered with minute confluent brown markings, with darker and lighter spots on the sides.
Total length, 685 millimetres; tail 115.
Habitat: Andes of Ecuador.
(5) L. microphthalmus.—Snout short, rounded; eyes very small; 7 supralabials, of which the third and the sixth or seventh are the largest; scales in 23 rows, dorsals tubercularly keeled; 159-161 ventrals; 52-55 subcaudal pairs.
Colour yellowish-brown or pale olive on the back, with dark brown triangles on the sides; posteriorly, the united triangles form cross-bands; a yellowish band from the eye to the side of the neck; belly dark brown with yellowish spots.
Total length, 630 millimetres; tail 100.
Habitat: Peru, Ecuador.
(6) L. pictus.—Snout obliquely truncate; two series of scales between the eye and the labials; scales in 21-23 rows, strongly keeled; 157-172 ventrals; 40-74 pairs of subcaudals.
Colour pale brown, with a dorsal series of large black-edged brown spots, which may form a vertebral zigzag band; a black streak behind the eye, and a vertical bar below the eye; belly yellowish, spotted with brown.
Total length, 310 millimetres; tail 43.
Habitat: Peru.
(7) L. alternatus.—Head narrow, elongate; 8-9 supralabials; scales in 29-35 rows, very strongly keeled; 167-181 ventrals; 34-51 pairs of subcaudals.
Colour brown, very elegantly marked with opposite or alternating pairs of large C-shaped markings, which are dark brown, edged with black and yellow, and separated by narrow interspaces of the ground colour; head dark·brown above, with a ⅄̅-shaped light marking, the transverse bar between the eyes; belly whitish, spotted with brown or black.
Total length, 1,190 millimetres; tail 110.
Habitat: Southern Brazil, Paraguay, Uruguay, Argentina.
(8) L. neuwiedii (known as the Urutù in Brazil; [fig. 70]).—Snout obtusely pointed; supraocular large, separated from its fellow by 6-9 longitudinal series of scales; 8 or 9 supralabials; scales very strongly keeled, in 21-27 rows; 168-182 ventrals; 41-53 subcaudals.
Colour yellowish or pale brown, with dark brown black-edged spots; the spots on the back form a single series or a double alternating series; a dark spot on the snout; a pair of dark bands from the vertex to the nape, and another from the eye to the angle of the mouth; belly yellowish, more or less powdered with brown.
Total length, 770 millimetres; tail 120.
Habitat: Brazil, Paraguay, Argentina.
Fig. 70.—Lachesis neuwiedii (known as the Urutù in Brazil). (After Lacerda.)
(9) L. ammodytoides.—Snout turned up, in the shape of a wart; two series of scales between the eye and the labials; scales in 23 or 25 rows, very strongly keeled; 149-160 ventrals; 30-38 pairs of subcaudals.
Colour pale brown, with large brown black-edged spots or cross-bands, which may alternate and form a zigzag band; a dark streak behind the eye; belly yellowish, spotted with brown.
Total length, 460 millimetres; tail 55.
Habitat: North-eastern Patagonia and Argentina.
(10) L. xanthogrammus.—Head elongate, snout short; scales in 27 rows, feebly keeled; 196 ventrals; 54 subcaudals.
Colour very dark olive, with a yellow zigzag line on each side from the head to the base of the tail; the angular parts enclose rhombic spaces and lateral triangles; top of head black, with a pair of undulating yellow bands from the nape to the vertex; a bright golden band round the snout; labials bright yellow; ventral shields black, paler in the middle, with yellow triangular spots at their extremities.
Total length, 1,530 millimetres; tail 190.
Habitat: Eastern Ecuador, Andes of Colombia.
(11) L. castelnaudi.—Head narrow and elongate; scales on the head smooth or feebly keeled, small; body-scales strongly keeled, in 25 or 27 rows; 230-253 ventrals; 72-83 subcaudals, all or majority in a single row.
Colour greyish or brown, with dark or light-edged spots or cross-bands; head with dark spots, one of which occupies the middle of the snout; a dark band from the eye to the angle of the mouth; belly brown or blackish, spotted with yellow.
Total length, 1,220 millimetres; tail 180.
Habitat: Brazil, Ecuador, Eastern Peru.
(12) L. nummifer.—Snout broad, rounded; 10 or 11 supralabials; scales in 23-27 rows, strongly keeled; 121-134 ventrals; 26-36 subcaudals, all or the majority single.
Colour pale brown, with a dorsal series of rhomboidal spots, which may form a zigzag band; belly whitish, uniform or spotted with dark brown.
Total length, 800 millimetres; tail 90.
Habitat: Mexico and Central America.
(13) L. godmani.—Snout broad, rounded; 9 or 10 supralabials; scales in 21 rows, strongly keeled; 135-142 ventrals; 22-34 subcaudals in a single row.
Colour brown, with or without a dorsal series of large darker spots; belly yellowish, more or less spotted with grey or blackish.
Total length, 610 millimetres; tail 60.
Habitat: Guatemala.
(14) L. lansbergii.—Snout pointed, turned up at the end, as in Vipera aspis; scales in 25-27 rows, strongly keeled; 152-159 ventrals; 29-35 subcaudals in a single row.
Colour yellowish-brown, pale brown, or grey, with a dorsal series of large rhomboidal or squarish spots, usually divided by a narrow yellow or orange vertebral line; cheeks blackish; belly powdered with brown, with or without whitish spots.
Total length, 575 millimetres; tail 70.
Habitat: from Southern Mexico to Colombia, Venezuela, and Brazil.
(15) L. brachystoma.—Similar to the foregoing species; scales in 23 (rarely 25) rows; 132-150 ventrals; 27-38 subcaudals.
Total length, 500 millimetres; tail 50.
Habitat: Southern Mexico and Central America.
(16) L. bilineatus.—Snout rounded; 7 or 8 supralabials; scales in 27-35 rows, strongly keeled; 198-218 ventrals; 59-71 subcaudals, all or majority in two rows. Tail prehensile.
Colour green, uniform or spotted with black; a lateral yellow streak; belly white; end of tail reddish.
Total length, 840 millimetres; tail 125.
Habitat: Brazil, Bolivia, Peru, Ecuador.
(17) L. undulatus.—Snout short, rounded; 11 supralabials; scales in 21 rows, the dorsals strongly or very strongly keeled; 149-171 ventrals; 41-49 pairs of subcaudals. Tail prehensile.
Colour olive or brown, sometimes speckled with black, with a dorsal series of rhomboidal dark spots or an undulous or zigzag band; belly yellowish or brownish, powdered with blackish.
Total length, 570 millimetres; tail 75.
Habitat: Mexico.
(18) L. lateralis.—Snout rounded; 9 supralabials; scales in 21 or 23 rows, rather strongly keeled; 171 ventrals; 59 subcaudals, in a single row. Tail prehensile.
Colour green, with a yellow line on each side of the body.
Total length, 485 millimetres; tail 75.
Habitat: Costa Rica.
(19) L. bicolor.—Very similar to the foregoing; scales in 21 rows; 164-167 ventrals; 62-67 subcaudals, in a single row.
Colour uniform green, yellowish on the belly.
Total length, 375 millimetres; tail 60.
Habitat: Guatemala.
(20) L. schlegelii.—Snout rounded; 8 or 9 supralabials; scales in 19-25 rows, more or less strongly keeled; 138-162 ventrals; 47-62 subcaudals, in a single row. Tail prehensile.
Coloration very variable, green or olive, spotted with black, or with pinkish, reddish, or purplish black-edged spots or cross-bars; belly yellow, spotted with green, or variegated; end of tail generally red.
Total length, 600 millimetres; tail 115.
Habitat: Central America, Colombia, Ecuador.
(21) L. nigroviridis.—Snout short, rounded; 9-11 supralabials; 19 rows of scales, rather feebly keeled; 134-146 ventrals; 49-54 subcaudals, in a single row. Tail prehensile.
Colour green or olive, spotted with black; head with a black streak on each side; belly yellowish.
Total length, 535 millimetres; tail 90.
Habitat: Costa Rica.
(22) L. aurifer.—Snout short and broad; 9 or 10 supralabials; scales in 19 rows, rather strongly keeled; 154-158 ventrals; 53-61 subcaudals, single. Tail prehensile.
Colour green, spotted with yellow; a black streak on the temple; belly greenish-yellow.
Total length, 825 millimetres; tail 145.
Habitat: Guatemala.
(c) Sistrurus.
Head very distinct from neck, covered above with nine large symmetrical shields; eyes rather small, with vertical pupils. Body cylindrical; scales keeled, with apical pits; tail short, ending in a segmented horny apparatus (rattle), producing a special sound; subcaudals all or the majority in a single row.
(1) S. miliarius (Ground Rattle-Snake).—9-11 supralabials; scales in 21 or 23 rows, strongly keeled; 127-139 ventrals; 27-36 subcaudals; rattle short, consisting at the most of 10 segments.
Colour greyish, yellowish, or brown, the vertebral line often orange; two undulating dark stripes from between the eyes to the occiput, the enclosed space usually orange; belly whitish, spotted with dark brown or black.
Total length, 520 millimetres; tail 70.
Habitat: South-eastern North America, from North Carolina to Texas.
(2) S. catenatus (Prairie Rattle-Snake, or Massasanga, [fig. 71]).—Two or three series of scales between the eye and the labials; 11-14 supralabials; scales in 23 or 25 rows; 136-153 ventrals; 20-31 subcaudals.
Colour the same as in S. miliarius: a dark spot on the parietal shields.
Total length, 680 millimetres; tail 80.
Habitat: Great Lakes district; United States east of the Rocky Mountains and west of the Mississippi; Northern Mexico.
(3) S. ravus.—11 or 12 supralabials; scales in 21 or 23 rows; 147 ventrals; 26 subcaudals.
Colour yellowish-brown, with a dorsal series of dark brown spots, longer than broad, and a series of transverse dark bars on each side; belly yellowish, spotted with blackish-brown.
Fig. 71.—Sistrurus catenatus (Prairie Rattle-Snake, or Massasanga). (After Holbrook and Stejneger.)
Total length, 200 millimetres; tail 22.
Habitat: Vera Cruz, Mexico.
(d) Crotalus (Rattle-Snakes).
These snakes differ from all others in that the end of the tail bears a series of large conical scales, forming rattles, each fitting into the next and movable in such a manner that when the reptile causes them to move they produce a strident sound ([fig. 72]).
Fig. 72.—A, Horny appendage (rattle) of Crotalus horridus (three-quarters natural size. After Garman). B, longitudinal section of the same. C, separated segments of the appendage: a, terminal point; h, basal segment (after Czermak).
The length of these animals often exceeds 2,000 millimetres. The head is flat, very large and expanded posteriorly, and terminated in front by a short, truncate snout; it is covered above with scales or small shields.
Rattle-Snakes are armed with enormous fangs enclosing a complete canal, which extends throughout almost their entire length. The poison-glands are of the size of a large almond.
The number of segments in the rattle is variable, but rarely exceeds 18 or 20. At the time of the shedding of the skin these segments fall off and are at once replaced. Contrary to the belief which was long entertained, their number bears no relation to the age of the snake.
Fig. 73.—Crotalus terrificus (Dog-faced Rattle-Snake, Cascavella in Brazil). (After Stejneger.)
Rattle-Snakes are met with especially in stony and arid localities, or among brushwood near water. They hardly ever bite except when surprised or attacked.
(1) C. terrificus (Dog-faced Rattle-Snake, Cascavella in Brazil; [fig. 73]).—Snout very short; three or four series of scales between the eye and the supralabial shields; body-scales in 23-31 rows, dorsals very strongly keeled; 160-199 ventrals; 18-30 subcaudals.
Colour brown, with a series of darker, light-edged rhombs, often lighter in the centre; a dark streak from the eye to the angle of the mouth; belly yellowish-white, uniform or spotted with brown; tail generally brown or blackish.
Total length, 1,320 millimetres; tail 130.
Habitat: Arizona, New Mexico, and Texas to Southern Brazil, and Northern Argentina.
(2) C. scutulatus (Texas Rattle-Snake; [fig. 74]).—13-16 supralabials; scales in 25 or 27 rows; dorsals striated and strongly keeled; 167-170 ventrals; 18-20 subcaudals.
Colour yellowish or greyish-brown, with a series of large dark brown light-edged rhomboidal spots; an oblique dark streak below the eye; belly uniform yellowish-white.
Total length, 760 millimetres; tail 65.
Habitat: Arizona, New Mexico, Texas, North Mexico.
(3) C. confluentus (Pacific or Mottled Rattle-Snake; [fig. 75]).—Upper head-scales small, striated; 13-18 supralabials; body scales in 25-29 rows, striated and strongly keeled; 168-197 ventrals; 17-34 subcaudals.
Colour yellowish, greyish, or pale brown, with a dorsal series of large brown or red spots, usually rhomboidal or transversely elliptic in shape; a light streak or triangular marking across the supraocular shields; belly yellowish, uniform or spotted with brown.
Total length, 1,520 millimetres; tail 140.
Habitat: Western North America, from British Columbia to South California, eastwards to Assiniboia, Dakota, Nebraska, Kansas, and Western and Southern Texas; Northern Mexico.
According to Holbrook, this reptile feeds upon young rabbits, squirrels, rats and other small mammals. It lays its eggs in August, and the young are hatched at once, and are capable of seeking their own food.
In captivity as well as under natural conditions the Mottled Rattle-Snake is an excessively irritable species. “The noise of the wind,” says Brehm, “or even the distant view of a man or animal, are sufficient to irritate it. It then coils itself up in a spiral, and places its head and tail in the centre of the disc thus formed, in a state of absolute immobility. After a short interval the creature raises its head to a height of about 8 to 12 inches above the ground, curves its neck in the shape of an S, and elevates its tail into a vertical position and shakes it vigorously, whereupon the strident noise caused by the rattle is heard. So rapid are the movements communicated by the Crotalus to its tail that they can scarcely be distinguished. So long as the Crotalus believes itself menaced it remains in the position that we have just described, and continues to sound its rattle. If one withdraws from the irritated snake, the sound gradually lessens and ceases, to begin again more vigorously when the reptile is once more approached.”
The bite of these snakes is exceedingly dangerous. Pigs wage an inveterate war against them and devour them.
At the Pasteur Institute at Lille, I have kept several of these reptiles in captivity for eighteen months and longer. They invariably refused their food, and I always had to resort to artificial feeding. They are easily capable of withstanding a prolonged fast.
(4) C. durissus (Common Rattle-Snake).—7 or 8 longitudinal series of scales between the supraoculars, 3 or 4 series of scales between the eye and the labials; 13-16 supralabials; scales in 25-29 rows, dorsals strongly keeled; ventrals 169-181; 24-32 subcaudals.
Fig. 74.—Crotalus scutulatus (Texas Rattle-Snake). (After Baird and Stejneger.)
Colour pale greyish or brownish, with a dorsal series of large blackish rhomboidal spots; a yellowish cross-line between the eyes; snout blackish; end of tail usually black; belly yellowish, more or less spotted with brown or black.
Total length may be as much as 8 feet (2,400 millimetres).
Habitat: South-eastern United States, from North Carolina to Florida and the mouths of the Mississippi.
(5) C. horridus.—Supraoculars considerably narrower than the space between them, which is covered by 3-8 longitudinal series of small scales; 12-16 supralabials; body scales in 23-29 rows, dorsals very strongly keeled; 165-178 ventrals; 19-29 subcaudals.
Colour greyish-brown, usually with a rusty vertebral stripe, and V- or M-shaped blackish cross-bands; head uniform above, with a dark band from the eye to the angle of the mouth; usually a pair of roundish or triangular dark spots on the nape; belly yellowish, uniform or spotted with blackish; end of tail blackish.
Total length, 1,340 millimetres; tail 135.
Habitat: United States, from Massachusetts and Iowa to Northern Florida and Texas.
(6) C. tigris.—13-15 supralabials; scales in 23 or 25 rows, dorsals strongly keeled; 166-181 ventrals; 26-46 subcaudals.
Colour yellowish or pale brown, with a dorsal series of brown spots and cross-bands posteriorly; sides with smaller dark spots; belly yellowish, spotted with brown.
Total length, 380 millimetres; tail 50.
Habitat: Southern California, Lower California, Nevada, Colorado, Arizona, and Northern Mexico.
(7) C. mitchelli.—14-16 supralabials; scales in 25 rows, striated, dorsals strongly keeled; 178-198 ventrals; 24-26 subcaudals.
Fig. 75.—Crotalus confluentus (Pacific or Mottled Rattle-Snake). (After Baird and Stejneger.)
Colour greyish-yellow to salmon-red, finely punctulated with brown, with a dorsal series of transverse darker spots; belly yellowish.
Total length, 1,020 millimetres; tail 90.
Habitat: Desert regions of Southern California, Lower California, and Arizona.
(8) C. triseriatus.—9-13 supralabials; scales in 21-25 rows, dorsals strongly keeled; 142-184 ventrals; 22-30 subcaudals.
Colour olive or brown, with a vertebral series of rather small dark brown spots edged with black and white; belly yellowish, spotted with dark brown, or dark grey-brown powdered with whitish.
Total length, 530 millimetres; tail 55.
Habitat: Mexico.
(9) C. polystictus.—Closely allied to the foregoing, but 4 internasals, 14 or 15 supralabials, and scales in 27-30 rows; 123-151 ventrals; 18-23 subcaudals.
Colour yellowish-brown, beautifully marked with 6 or 7 longitudinal series of alternating, elongate, dark brown, black- and white-edged spots, separated by narrow interspaces of the ground-colour; a pair of diverging dark bands on the top of the head, separated by a narrow pinkish-white streak; belly pinkish or yellowish, spotted with dark brown.
Total length, 600 millimetres; tail 60.
Habitat: Tableland of Mexico.
(10) C. lepidus.—12 supralabials; scales in 21 or 23 rows, dorsals strongly keeled; 153-169 ventrals; 24-31 subcaudals.
Colour brown or greenish-grey, with dark brown or jet-black light-edged cross-bands, narrowing on the sides; two dark spots, or a V- or heart-shaped black marking on the nape; belly dirty white, spotted with brown.
Total length, 350 millimetres; tail 60.
Habitat: Western Texas, New Mexico, Arizona, North Mexico.
(11) C. cerastes (Horned Rattle-Snake; [fig. 76]).—Supraocular transformed into a raised horn-like process; 11-13 supralabials; scales in 21 or 23 rows; dorsals feebly keeled, each scale along the middle of the back with a central tubercular swelling; 146 ventrals; 17 subcaudals.
Fig. 76.—Crotalus cerastes (Horned Rattle-Snake.) (After Baird and Stejneger.)
Colour yellowish, with a dorsal series of rather indistinct brown blotches; a narrow brown streak from the eye to the angle of the mouth.
Total length, 250 millimetres; tail 20.
Habitat: Desert regions of Southern California, Nevada, Arizona, and Utah.
F.—HYDROPHIINÆ (SEA-SNAKES).
The Sea-Snakes, which are found in great numbers on the shores of the Indian Ocean, are common throughout the whole of the tropical zone of the China Sea and the Pacific. They are met with from the Persian Gulf to the west coast of Equatorial America, but are entirely absent from the east coast of the same continent and the west and east coasts of Africa.
They often travel in companies. All are poisonous, and very savage. They never come to land, and move with difficulty if taken out of the water, although they are excellent swimmers. It is impossible to keep them in captivity in aquariums, and they die in two or three days. Their food consists of fishes and crustacea. Their tail is prehensile, and they make use of it as an anchor to attach themselves to coral reefs when they wish to rest. They generally float on the surface of the waves, but can dive to great depths, thanks to the extreme dilatability of their lungs, which enables them to store up large reserves of air. They are viviparous.
In these snakes, the head, which is always very small, is scarcely distinct from the body. It is often covered with nine large shields. The body is laterally compressed, and the tail, which serves as a fin, is similarly flattened. The nostrils open on the upper surface of the snout, between the nasal shields. The eyes are always very small.
The number of species at present known is considerable; they are divided into ten genera. We shall confine ourselves here to mentioning the principal diagnostic characters of these genera, and to describing the most common species.
Fig. 77.—Skull of Hydrus platurus. (After G. A. Boulenger, op. cit.)
(1) Hydrus.
([Fig. 77].)
Maxillaries longer than the ectopterygoids, not extending forwards as far as the palatines; poison-fangs grooved, rather short, followed, after an interspace, by 7 or 8 solid, backwardly curved teeth. Snout long, bearing the nostrils on its upper surface; head-shields large, nasals in contact with each other. Body rather short; scales hexagonal or squarish, juxtaposed; no distinct ventral scales.
Fig. 78.—Hydrus platurus (syn. Pelamis bicolor).
(After Krefft.)
The principal species of this genus is H. platurus (syn. Pelamis bicolor, [fig. 78]).
Coloration black or brown and yellow, with very variable markings.
Total length, 700 millimetres; tail 80.
Habitat: Indian Ocean, Tropical and Sub-tropical Pacific.
(2) Thalassophis.
Poison-fangs followed by 5 small teeth. Snout short; nostrils superior, horizontal, between two nasal shields and an internasal; frontal and parietal shields large; præocular present. Body rather elongate; scales hexagonal, juxtaposed; no distinct ventral scales.
T. anomalus.—Body with dark annuli, wider on the back.
Total length, 810 millimetres; tail 84.
Habitat: Java.
(3) Acalyptophis.
Maxillaries longer than the ectopterygoids; frontal and parietal shields broken up into scales. Body rather elongate; scales subimbricate; no distinct ventrals.
A. peronii.—Greyish or pale olive, with dark cross-bands; belly whitish.
Total length, 890 millimetres; tail 115.
Habitat: Western Tropical Pacific.
(4) Hydrelaps.
Snout short; 6 teeth behind the poison-fangs; nostril in a single nasal shield; head-shields large. Body feebly compressed; scales imbricate; ventral scales small, but well developed.
H. darwiniensis.—Body with yellowish-white and blackish annuli, the black rings narrower on the belly; head dark olive spotted with black.
Total length, 435 millimetres; tail 43.
Habitat: North Australia.
(5) Hydrophis.
([Fig. 79].)
Fig. 79.—Hydrophis coronatus. (After Sir Joseph Fayrer.)
Poison-fangs large, followed by a series of 7-18 solid teeth. Head small; nostrils on the upper surface of the snout, pierced in a single nasal shield; head-shields large; præocular present. Body long, often very slender anteriorly; scales on the anterior part of the body imbricate, rectangular, keeled or tubercular; ventrals more or less distinct, very small.
A considerable number of (at least 22) species of Hydrophis are known. Those most frequently met with are the following:—
H. spiralis.—Olive above, yellowish beneath, with black rings; head black above, with a horse-shoe-shaped yellow mark, the convexity of which rests on the præfrontal shields; end of tail black.
Total length, 400 millimetres. Grows to 1,800 millimetres.
Habitat: Coasts of India, and the Malay Archipelago.
H. cærulescens.—Grey above, with black cross-bands, which form complete rings, or are interrupted on the belly; head uniform black.
Total length, 665 millimetres; tail 75.
Habitat: Bombay Coast, Bay of Bengal, Straits of Malacca.
H. nigrocinctus.—Pale olive on the back, yellowish on the belly, with black annuli, which are broader on the back.
Total length, 1,000 millimetres; tail 100.
Habitat: Bay of Bengal and Straits of Malacca.
Fig. 80.—Hydrophis elegans. (After Krefft.)
H. elegans ([fig. 80]).—Yellowish-white, back with transverse rhomboidal black spots, separated by a series of small black spots; belly with black spots or cross-bars; head blackish, with a more or less distinct light crescentic marking across the snout, from above the eyes.
Total length, 710 millimetres; tail 60.
Habitat: North coast of Australia.
H. gracilis.—Bluish-black or greyish, olive above in the adult, with more or less distinct lighter cross-bands anteriorly. Young sometimes with rhombic black cross-bands extending to the belly, or sub-interrupted on the sides.
Total length, 1,020 millimetres; tail 90.
Habitat: Coasts of Persia, India, and Ceylon; Malay Archipelago.
H. cantoris.—Body dark olive or blackish anteriorly, with yellowish cross-bands above; posterior part of body olive above, yellowish on the sides; tail with olive vertical bars; a blackish streak along the belly.
Total length, 1,100 millimetres; tail 90.
Habitat: Bay of Bengal.
H. fasciatus.—Head and neck black, the latter with yellowish cross-bands; body pale, with black annuli, which are broader on the back.
Total length, 1,000 millimetres; tail 85.
Habitat: From the coasts of India to China and New Guinea.
H. obscurus (syn. H. stricticollis).—Olive or dark green above, with yellowish cross-bars, which form complete rings round the slender anterior part of the body; a yellow spot on the snout, and a yellow streak on each side of the upper surface of the head.
Total length, 970 millimetres; tail 105.
Habitat: Bay of Bengal, Malay Archipelago.
H. leptodira.--Black, with yellow cross-bars on the neck, and complete annuli on the body, the bars and annuli numbering 77.
Total length, 525 millimetres; tail 40.
Habitat: Mouths of the Ganges.
(6) Distira.
([Fig. 81].)
Poison-fangs large, followed by 4-10 grooved teeth. Head larger than in Hydrophis; body more or less elongate; scales on the anterior part of the body imbricate; ventrals more or less distinct, and always very small.
The species of this genus, 18 in number according to the British Museum Catalogue, are found in the Indian and Pacific Oceans, from the Persian Gulf to Japan and New Caledonia.
The most important are:—
D. ornata.—Uniform blackish-olive on the back, whitish on the belly.
Total length, 1,200 millimetres; tail 130. Habitat: From the Mouth of Persian Gulf, and the coasts of India and Ceylon to New Guinea, and North Australia.
D. subcincta.—Trunk with 41 broad dark cross-bands, about as broad as the interspaces, not extending downwards to the middle of the side; a series of small roundish, blackish spots along the lower part of the sides.
Total length, 1,070 millimetres; tail 100.
Habitat: Indian Ocean.
Fig. 81.—Skull of Distira.
(After G. A. Boulenger, op. cit.)
D. cyanocincta.—Greenish-olive above, with dark olive or black cross-bars or annuli, broader on the back, and sometimes joined by a black band along the belly, or yellowish, with a black vertebral stripe and a few bars on the neck.
Total length, 1,500 millimetres; tail 140.
Habitat: From the Persian Gulf and the coasts of India to China, Japan, and Papuasia.
D. jerdonii.—Olive above, yellowish on the belly, with black cross-bands forming complete rings in young and half-grown specimens; a black spot sometimes present between each pair of annuli.
Total length, 910 millimetres; tail 100.
Habitat: Bay of Bengal, Straits of Malacca, Borneo.
(7) Enhydris.
Two large poison-fangs, and 2-4 small feebly grooved teeth. Body short and stout; scales hexagonal or squarish, juxtaposed, disappearing almost completely on the belly.
E. curtus.—Above with dark transverse bands, broadest in the middle; end of tail black.
Total length, 750 millimetres; tail 75.
Habitat Coasts of India and Ceylon.
Fig. 82.—Enhydrina valakadien (syn. E. bengalensis).
(8) Enhydrina.
Two large poison-fangs, followed by 4 solid non-grooved teeth. Body moderately elongate; scales imbricate; ventrals distinct but very small.
E. valakadien (syn. E. bengalensis; [fig. 82]).—Colour olive or grey, with black transverse bands, usually less distinct in the adult; sides and belly whitish.
Fig. 83.—Skull of Platurus olubrinus.
(After G. A. Boulenger, op. cit.)
Total length, 1,300 millimetres; tail 190.
Habitat: From the Persian Gulf along the coasts of India and Burma, to the Malay Archipelago and Papuasia.
(9) Aipysurus.
Maxillaries a little longer than the ectopterygoids; poison-fangs moderate, followed, after a short interval, by 8-10 grooved teeth; anterior mandibular teeth feebly grooved. Snout short; head shields large, or broken up into scales. Body moderate; scales imbricate; ventrals large, keeled in the middle.
A. australis.—Brown, or cream-colour, with brown spots forming more or less distinct cross-bars.
Total length, 930 millimetres; tail 110.
Habitat: Coasts of New Guinea and Australia.
Other species of Aipysurus (A. eydouxii, annulatus, and lævis) are found on the coasts of Singapore, Java, Celebes, and the Philippine and Loyalty Islands.
Fig. 84.—Platurus laticaudatus (syn. P. fischeri).
(After Sir Joseph Fayrer.)
(10) Platurus.
([Figs. 83], [84].)
Two large poison-fangs, and only one or two small solid teeth near the posterior extremity of the maxillary. Head shields large; nostrils lateral, the nasal shields separated by the internasals. Body greatly elongate; scales smooth and imbricate; ventrals and subcaudals large.
Four species, distributed in the eastern parts of the Indian Ocean and in the Western Pacific.
P. laticaudatus (syn. P. fischeri; [fig. 84]).—Olive above, yellowish on the belly, with 29-48 black annuli.
Total length: 970 millimetres; tail 90.
Habitat: From the Bay of Bengal to the China Sea and the Western South Pacific Ocean.
P. colubrinus ([fig. 83]).—Olive above, yellowish on the belly, with 28-54 black annuli, some or all of which may be interrupted below.
Total length, 1,270 millimetres; tail 125.
Habitat: From the Bay of Bengal to the China Sea and the Western South Pacific Ocean.
P. muelleri.—62 black annuli, some of which are interrupted on the belly.
Habitat: Only found in the South Pacific Ocean (subtropical zone), as far as the New Hebrides and the shores of Tasmania.
P. schistorhynchus.—Coloration and size as in P. colubrinus: body with 25-45 annuli.
Habitat: Western Tropical Pacific.
G.—GEOGRAPHICAL DISTRIBUTION OF THE PRINCIPAL GENERA OF POISONOUS SNAKES IN THE FIVE DIVISIONS OF THE WORLD.
| (1) EUROPE. | |||
|---|---|---|---|
| Families | Sub-Families | Genera | Geographical Area |
| Colubridæ | Dipsadomorphinæ | Cœlopeltis | Borders of the Mediterranean in France and Spain; Italy (only in Liguria). |
| Viperidæ | Viperinæ | Vipera | France, Italy, Switzerland, Austria-Hungary, Germany, Belgium, Sweden and Norway, Gt. Britain, Spain and Portugal, Bosnia and Herzegovina, Southern Russia, Turkey and Greece. |
| (2) ASIA. | |||
| Colubridæ | Hydrophiinæ | Hydrus Thalassophis Acalyptophis Hydrelaps Hydrophis Distira Enhydris Enhydrina Aipysurus Platurus | Persian Gulf, Indian Ocean, Bay of Bengal, Straits of Malacca, China Sea, Philippines, and Malay Archipelago. |
| Elapinæ | |||
| Bungarus | India, Ceylon, Burma, Indo-China, Southern China, Dutch Indies, Borneo. | ||
| Naja | India, Ceylon, Burma, Indo-China, Dutch Indies, Philippines. | ||
| Hemibungarus | South-eastern Asia, India, Japan, Philippines. | ||
| Callophis | South-eastern Asia, India, Burma, Indo-China, Formosa, Southern China. | ||
| Doliophis | Indo-China, Malay Peninsula. | ||
| Viperidæ | Viperinæ | Vipera | Turkestan, Ural, Siberia, Caucasus, Persia, Armenia, Western China, India, Ceylon, Himalayas. |
| Pseudocerastes | Persia. | ||
| Cerastes | Arabia, Palestine. | ||
| Echis | Persia, Arabia, India, Baluchistan, Afghanistan. | ||
| Crotalinæ | Ancistrodon | Transcaspia, Turkestan, Himalayas, Southern China, Formosa, Japan, Ceylon, Java. | |
| Lachesis | South-eastern Asia, India, Southern China, Indo-China, Formosa, Sumatra. | ||
| (3) AFRICA. | |||
| Colubridæ | Elapinæ | Boulengerina | Central Africa. |
| Elapechis | Central and South Africa. | ||
| Naja | Egypt, Central and West Africa, Morocco, Congo, Angola. | ||
| Sepedon | South Africa, Cape of Good Hope. | ||
| Aspidelaps | South and South-east Africa, Mozambique. | ||
| Walterinnesia | Egypt. | ||
| Homorelaps | South Africa, Cape of Good Hope. | ||
| Dendraspis | Central and South Africa, Angola, Great Lakes, Congo, Transvaal. | ||
| Viperidæ | Viperinæ | Causus | West Africa, Gambia, Great Lakes, Congo, Angola, Transvaal. |
| Vipera | Morocco, Algeria, Tunis, Egypt, Mozambique. | ||
| Bitis | Zanzibar, Zambesia, Cape, Transvaal, Congo, the Gaboon, Benguella, Angola, Senegal, Nigeria. | ||
| Cerastes | North Africa, the Sahara. | ||
| Echis | North Africa, Lake Chad, Soudan, Egypt, Somaliland, Socotra. | ||
| Atheris | Tropical Africa, Dahomey, Lagos, the Cameroons, the Gaboon, Congo. | ||
| Atractaspis | Tropical and South Africa, Congo, Angola, Lake Chad, the Gaboon, Dahomey, Gold Coast, Zanzibar, Somaliland, Natal, and the Cape. | ||
| (4) OCEANIA. | |||
| Colubridæ | Hydrophiinæ | Hydrus Thalassophis Hydrelaps Hydrophis Distira Enhydris Enhydrina Aipysurus Platurus | Equatorial and Sub-tropical Pacific Ocean, the Moluccas, Papuasia, New Guinea, Celebes, Timor, Australia, Tasmania, New Caledonia, New Hebrides. |
| Elapinæ | Ogmodon | Fiji Islands. | |
| Glyphodon | Northern Australia, New Guinea. | ||
| Pseudelaps | Australia, the Moluccas, Papuasia. | ||
| Diemenia | Australia, New Guinea. | ||
| Pseudechis | Australia, New Guinea. | ||
| Denisonia | Australia, Solomon Islands, Tasmania. | ||
| Micropechis | New Guinea, Solomon Islands. | ||
| Hoplocephalus | Australia. | ||
| Tropidechis | Australia. | ||
| Notechis | Australia, Tasmania. | ||
| Rhinhoplocephalus | Australia. | ||
| Brachyaspis | Australia. | ||
| Acanthophis | Moluccas, Papuasia, Northern Australia. | ||
| Elapognathus | Australia. | ||
| Rhynchelaps | Australia. | ||
| Furina | Australia. | ||
| (5) AMERICA. | |||
| Colubridæ | Elapinæ | Elaps | Mexico, Central America, Bolivia, Ecuador, Peru, Colombia, Brazil. |
| Viperidæ | Crotalinæ | Ancistrodon | North America, Florida, Texas, Mexico, Guatemala. |
| Lachesis | Central and South America, Martinique, St. Lucia. | ||
| Sistrurus | North America east of the Rocky Mountains, Mexico. | ||
| Crotalus | Southern Canada, British Columbia, Central America, Guiana, Venezuela, Brazil, Uruguay, Northern Argentina. | ||
PART II.
CHAPTER IV.
SECRETION AND COLLECTION OF VENOM IN SNAKES.
Non-poisonous as well as poisonous snakes possess parotid and upper labial glands capable of secreting venom. In the former the organs of inoculation are wanting, but we shall see later on that the toxic secretion of their glands is just as indispensable to them as to the snakes of the second category for the purpose of enabling them to digest their prey.
For the morphological, histological, and physiological demonstration of the existence of these glands in harmless reptiles we are indebted to Leydig (1873), whose discovery has since been confirmed and extended by the researches of Phisalix and Bertrand, Alcock, L. Rogers, and L. Lannoy.
The parotids of Grass Snakes are mixed glands of the sero-mucous type. The serous tubes are situate almost exclusively in the posterior portion of the gland. As we proceed towards the anterior portion, we find that these serous tubes are interspersed with others which are exclusively mucous or sero-mucous, and they become entangled with those of the upper labial gland, properly so-called. The substance of the gland is divided into several lobes by bands of connective tissue; the tubes are separated by septa of the same tissue, in extremely delicate layers (Lannoy).
In poisonous snakes these glands are much more developed, especially in their hinder portions, which sometimes assume enormous dimensions. They may attain the size of a large almond (Crotalus, Naja), and they then occupy the spacious chamber already described (Chap. I., p. 10), which is situated behind the eye on each side of the skull.
Each gland is surrounded by a thick capsule of fibrous tissue, two prolongations of which, the one anterior, the other posterior, keep it in its place beneath the masseter muscle. A portion of the latter is inserted in the capsule itself, in such a way that when the snake closes its jaws to bite, the gland is forcibly compressed and the contained liquid is squeezed into its excretory duct.
Between the muscle and the envelope of the gland there is a serous pouch, which enables the one to slide over the other.
The excretory duct runs along the outer side of the upper jaw, and opens by a slit at the base of the poison-fang, with which it inosculates at right angles in a little muscular mass forming a sphincter.
In the normal position of repose, the poison-fang is always concealed by a gingival fold of mucous membrane, in the substance of which are buried a few fibres of the tendon of the internal pterygoid muscle. When the latter contracts, the tooth is almost completely exposed, and the efferent duct of the gland then assumes an oblique position, which allows of the direct discharge of the venom through the canal which runs along the greater portion of the length of the tooth.
When the poison-fangs are folded back in their sheath, the poisonous secretion can escape freely into the buccal cavity by the slit situated at the base of the fangs.
At the moment when the animal is about to bite, when it throws back its head and opens its jaws, directing its fangs forwards, the muscles that come into action (masseters, temporals, and pterygoids) compress the glands on each side, and cause the venom to be expelled in a sudden jet, as if by a sort of ejaculatory process. In the case of certain species the venom may be projected to a distance of more than a yard.
The quantity of venom secreted by the glands varies greatly, according to the length of time which has elapsed since the animal took its last meal, and in accordance with a number of other conditions not very easy to determine.
The Common Viper of Europe yields scarcely 10 centigrammes of poison, while an adult Indian Cobra may excrete more than 1 gramme.
Freshly collected venom is a syrupy liquid, citron-yellow or slightly opalescent white in colour.
When dried rapidly in vacuo or in a desiccator over calcium chloride, it concretes in cracked translucent lamellæ like albumin or gum arabic, and thus assumes a crystalloid aspect. In this condition it may be kept indefinitely, if protected from light, air, and moisture. It dissolves again in water just as readily as albumin or dried serums.
I regularly weighed the dry residue from eleven bites made on a watch-glass by two Naja haje, received at my laboratory from Egypt at the same time, and placed in the same case. Both snakes were approximately of equal length, 1,070 millimetres. Throughout the entire course of the experiment, which lasted one hundred and two days, neither of them took any food, but they drank water and frequently bathed.
The results that I obtained are shown in the table on next page.
It will be seen that in one hundred and two days, an adult Naja haje is capable of producing on an average 0·632 gramme of liquid venom, equal to a mean weight of 0·188 gramme of dry extract; and we may conclude that 1 gramme of liquid gives 0·336 gramme of dry venom.
In Australia it has been found by MacGarvie Smith, of Sydney, that Pseudechis porphyriacus yields at each bite a quantity of venom varying from 0·100 gramme to 0·160 gramme (equal to 0·024 gramme to 0·046 gramme of dry venom), and that a Hoplocephalus curtus (Tiger Snake) yields 0·065 gramme to 0·150 gramme of liquid venom, with 0·017 gramme to 0·055 gramme of dry residue. In all the experiments of this physiologist, the proportion of dry residue varied from 9 to 38 per cent. of the liquid venom excreted by the reptile.
A Lachesis lanceolatus (Fer-de-lance) from Martinique, of medium size, when both of its glands were squeezed, furnished me with 0·320 gramme of liquid venom, and 0·127 gramme of dry extract.
| Number of bite | Date | NAJA HAJE I. Weight of Venom | NAJA HAJE II. Weight of Venom | ||
|---|---|---|---|---|---|
| Fresh | Dry | Fresh | Dry | ||
| Gramme | Gramme | Gramme | Gramme | ||
| 1 | April 20 | 0·119 | 0·031 | — | — |
| 2 | April 23 | — | — | 0·151 | 0·043 |
| 3 | May 14 | 0·124 | 0·035 | — | — |
| 4 | May 21 | — | — | 0·132 | 0·037 |
| 5 | May 28 | — | — | 0·091 | 0·019 |
| 6 | June 2 | 0·127 | 0·039 | — | — |
| 7 | June 19 | — | — | 0·121 | 0·043 |
| 8 | July 1 | — | — | 0·078 | 0·026 |
| 9 | July 2 | 0·122 | 0·048 | — | — |
| 10 | July 25 | — | — | 0·111 | 0·034 |
| 11 | July 26 | 0·079 | 0·021 | — | — |
| Totals ... | 0·581 | 0·174 | 0·684 | 0·202 | |
Two large Cerastes vipers, from Egypt, yielded me, one 0·123 gramme, the other 0·085 gramme of liquid venom, which, after desiccation, left respectively 0·027 gramme and 0·019 gramme of dry residue.
Under the same conditions, a magnificent Crotalus confluentus (Mottled Rattle-Snake), for which I was indebted to the kindness of Mr. Retlie, of New York, yielded, two months after reaching my laboratory, 0·370 gramme of liquid venom and 0·105 gramme of dry extract in a single bite.
The total quantity of liquid venom that I found contained in the two glands of the same reptile, when extirpated after death, and after the snake had been in the laboratory for five months, amounted to 1·136 gramme, which gave 0·480 gramme of dry extract.
We see, therefore, that the proportion of dry residue, including albumin, salts, the débris of leucocytes, and the toxic substance, oscillates between 20 and 38 per cent. Its strength varies with the length of time that has elapsed since the snake’s last bite or last meal.
From the histological standpoint, the process of the secretion of venom, in the cells of the glands, may be divided into two stages:—
(a) A stage of nuclear elaboration.
(b) A stage of cytoplasmic elaboration.
These two stages are superposed and successive.
In addition to the passive exchanges between the nucleus and the cytoplasm, the nuclear mass actively participates in the secretion. This participation is rendered evident:—
(1) By the difference of chromaticity in the granules of chromatin.
(2) By the emission of formed granules into the cytoplasm, granules which are spherical and of equal bulk, with the chromatic reactions of differentiated intranuclear chromatin.
(3) By the exosmosis of the dissolved nuclear substance, accessorily formed in an ergastoplasmic shape.
These formations constitute, on the one hand, the granules of venogen; on the other, the ergastoplasmic venogen. In the poison-cell of Vipera aspis, and in the serous cell of the parotid glands of Tropidonotus natrix (Grass Snake) the venogen is elaborated chiefly in granular form.
On entering the perinuclear cytoplasm, the granule of venogen and the ergastoplasmic venogen may either disappear immediately, as happens in periods of cellular stimulation, or else continue to exist for some time within the cell, indicating a period of saturation by the elaborated material.
During cytoplasmic activity the granule of venogen and the ergastoplasmic venogen disappear.
Nuclear elaboration and cytoplasmic elaboration constitute two different cycles of secretion. The effect of the nuclear cycle is to furnish the cytoplasm with the elements necessary for the work of secretion properly so-called. Cytoplasmic elaboration is not confined to the basal protoplasm, but takes place throughout the entire cell: it is especially active in the perinuclear cytoplasm.
The granule of venogen is distinguished from the granule of elaborated venom by its affinity for Unna’s blue, safranin, and fuchsin. The granule of venom has an affinity for eosin; it is never excreted in granular form, but after intracellular dissolution.
Venogen is never met with in the lumen of the gland-tube.[6]