Fossil Apoda are not known; their subterranean life does not favour preservation.

Only family, Coeciliidae. About forty species are known. These have been placed in seventeen genera, mostly on comparatively slight grounds, and several of these genera are probably unnatural, the distinctive characters having undoubtedly been developed independently in various countries. We have to remember that the recent species are the remainder of a formerly much more numerous group; it is also likely that more will be discovered in the tropical forests of South America and Sumatra.

Boulenger^[42] has distinguished them as follows:–

Ichthyophis glutinosa extends from the slopes of the Himalayas to Ceylon, the Malay islands, and into Siam. A second species, I. monochrous, occurs in Malabar, Malacca, Borneo, and Java. I. glutinosa reaches about one foot in length, with a greatest thickness of a little more than half an inch. The general colour is dark brown or bluish black, with a yellow band along each side of the body.

This species has been studied extensively by the Sarasins.^[43] It breeds in Ceylon after the spring monsoon. The ovarian egg is oval, measuring 9 by 6 mm. The yolk is yellow; the blastoderm lies towards one of the poles. The strong vitelline membrane becomes surrounded in the oviduct by a dense albuminous membrane, which forms twisted chalazae, just like those of birds' eggs, and by these two cords the eggs are strung together. Around all this lies another mantle of albumen. The female digs a hole close to the surface in moist ground near running water, and there lays about two dozen eggs. The egg-strings become glued together, entangled into a bunch, and the female coils herself round the bunch and remains in that position, probably to protect the eggs against other burrowing creatures, as blind snakes (Typhlops and Rhinophis) and certain limbless lizards, with which the ground literally swarms. During this kind of incubation the eggs assume a round shape, and grow to twice their original size, and the mature embryo weighs four times as much as the newly laid egg.

The external gills are delicately fringed and red, and they move up and down in the fluid of the egg. The body of the embryo is at first white, but becomes pigmented with dark grey. A strong line of lateral sense-organs is formed, and a ring of them lies around the eye and others on other parts of the head. The short tail develops a fin. Of the three pairs of gills the third is the shortest, and is generally turned dorsalwards. In embryos of 4 cm. in length the longest gill measures as much as 2 cm. Yolk is still present in embryos which have reached the surprising length of 7 cm. Then the gills begin to shrink a little, and at this time one pair of gill-clefts breaks through at the base of the third external gill.

When the larvae are hatched the gills are lost. The young larva takes to the water in a gill-less state, and moves about like an eel. At the bottom of the gill-hole on each side two arches are visible, and there are at this stage neither inner nor outer gills. The larvae frequently come up to the surface to breathe. The eyes are large and clearly visible, but the tentacles are still undeveloped. The epidermal sense-organs are numerous, and appear as white spots in the grey skin; about fifty extend from the gill-opening to the tip of the tail.

Ichthyophis seems to live a long time in the larval state. At last the gill-clefts close, the tail-fin disappears, and the tentacles come to the surface. The whole skin assumes a totally new structure, and the fish-like larva turns into a burrowing, subterranean creature so terrestrial that it gets drowned when made to remain in the water.

Hypogeophis.–According to A. Brauer^[44] three species of Coecilians are found in the Seychelles: Cryptopsophis multiplicatus, which is rare, Hypogeophis rostratus and H. alternans. They live in moist ground, near the coast in swamps, higher up in humus, under rotten trees and rocks, down to the depth of one foot. In the island of Silhouette, Brauer found them in brooks, at least during the dry season, from May to September. The natives call them "vers de terre." They seem to propagate during the greater part of the year, provided there is sufficient moisture. The female coils round the eggs, which vary from half a dozen to thirty in number, those of H. rostratus measuring 7-8 mm., those of H. alternans only 4-5 mm.

The embryos undergo their whole development in the egg. Four pairs of gill-clefts break through, the first between the hyoid and the first branchial arch, the fourth between the third and fourth branchial arches. There appears also a spiracular cleft between the quadrate and the hyoid arch; this cleft is, however, only developed dorsally, and persists for a shorter time. The external gills appear at the same time as the clefts, upon the first three branchial arches; the third gill is the latest, and remains in a vestigial condition covered up by the two others. The gills, of which the second is the longest, are not (as stated by the Sarasins) direct prolongations of the gill-arches, but they begin as button-like growths upon the arches. They begin to disappear with the absorption of the yolk, getting actually smaller. In embryos of 6 cm. they are 6 mm. long, while in embryos of 6.5 cm. they are reduced to 4.5 mm. in length. The first to disappear is the third gill, of course by being resorbed; and the clefts are closed before the creature leaves the egg. Hypogeophis not leading an aquatic larval life possesses no tail-fin in the embryonic state, the gill-holes are closed, and the epidermal sensory organs disappear long before the time of hatching.

Vestiges of gills appear also on the hyoid and on the mandibular arch, but on the latter they are of very short duration. Those of the hyoid gradually fuse with the first of the branchial gills, and these also concentrate with their bases so that they ultimately seem to spring from one common stem. Brauer remarks that the distinction between internal and external gills seems to be one of degree only; the hyoidean and mandibular gills namely start from the hinder margin of the arches, just like the internal gills of Torpedo according to Ziegler, while the other gills start from the sides of the branchial arches. He also found a pair of little swellings behind the last gill-cleft, and an unpaired swelling (corresponding with a double one in Ichthyophis) in front of the vent. Not unreasonably he sees in these swellings the last, very transitional vestiges of the paired limbs.

Typhlonectes compressicauda of Guiana and Venezuela is one of the largest Coecilians, reaching a length of 18 inches, with a body-diameter of ¾ inch. The general colour, as in most of these creatures, is olive brown to black. A sort of adhesive disc surrounding the vent occurs in this genus. Peters, who described this species, found in one female six embryos of comparatively enormous size, one of them being 157 mm. (more than 6 inches) long, and 12 mm. thick, and devoid of a tail-fin. Instead of lateral gill-openings there is a "bag" on each side 55 mm. long, upon which is distributed a blood-vessel. The Sarasins have examined the same specimen: The gills are not a bag, but consist of two flat, unbroken membranes which are closely connected with each other. In fact the outer gills of all Amphibia may be said to begin in the shape of small bags, whence sprout secondarily the gill-fringes; but in Typhlonectes they form these flaps instead of growing into the usual three gills. The embryos have no epidermal sense-organs, but plenty of skin-glands. Probably when born they take at once to terrestrial life, the flaps are possibly shed at birth, and there remains a little cicatrix.

Dermophis thomensis of West Africa (its other relations live in East Africa, South and Central America) is also viviparous.

CHAPTER V

LISSAMPHIBIA (CONTINUED)–URODELA

Order II. URODELA or TAILED AMPHIBIA.

The recent tailed Amphibia, Salamanders and Newts in the wider sense, have been grouped into four families which can be conveniently diagnosed by the following characters:–

These four families are closely allied to each other, especially the Amphiumidae and the Salamandridae.

The geographical distribution of the Urodela is essentially Periarctic, except that about one dozen species each of Amblystoma and of Spelerpes extend southwards into Central America, and in the case of the latter genus even into the Andesian parts of South America. Plethodon platense inhabits Argentina.

The Urodela afford good reasons for dividing the Periarctic region into three co-ordinate sub-regions, namely, Nearctic, Eastern and Western Palaearctic. The difference between the European and the Eastern Asiatic fauna is well marked; the two are–at least with our present knowledge–separated by a wide stretch of country very poor in Urodele forms; while, lastly there are not a few resemblances between this Eastern Asiatic and the American fauna. The Urodela thus lend no support to the usual division of the Periarctic into a Palaearctic and a Nearctic sub-region. Nor is it possible to divide the Palaearctic into a Eurasian and a Mediterranean province. We have in this case to distinguish between an American, an Asiatic, and a European fauna. The Asiatic or Eastern Palaearctic sub-region assumes the central position, at least from a merely geographical point of view. It would be unjustifiable to assume a spreading from this centre into Europe, and, on the other hand, into America. The centre existed more probably in the Arctic circle, now devoid of Urodela.

So far as mere numbers of species are concerned the huge Asiatic or Eastern Palaearctic region is the poorest, but it is also the least explored, and China will probably yield a good many new forms. We know at present only 15 species, nearly all from the eastern half. These 15 species represent no less than 11 genera, 8 of which (= 73 per cent) are peculiar to the sub-region. Next comes the Western Palaearctic or European sub-region with about 21 recent species of 5 genera, 4 of which are peculiar. America is by far the richest, with no less than 66 species (36 eastern, about 16 western, and the rest Central American, etc.), belonging to 19 genera, 17 of which (= 90 per cent) are peculiar to the New World. But this richness in species is due mainly to the abundance of the two genera Amblystoma and Spelerpes, just as Europe is characterised by its many Tritons.

One of the most striking features of the Asiatic sub-region is its difference from the European. They have very little in common. Pachytriton, Tylototriton, and two species of Triton (T. pyrrhogaster and T. sinensis) are the only Salamandrinae, while all the rest are Lechriodont (see p. 102), like the American Urodela, excepting the two American Tritons, T. torosus and T. viridescens.

Geographical Distribution of the Urodela

The occurrence of an Amblystoma, A. persimile, in the mountains of Siam and Burmah, is most suggestive, and others will in all probability be found. It must also be borne in mind that the differences between the genera of Amblystomatinae are in reality very slight; and the same applies to the sub-families themselves. The presence or absence of teeth on the parasphenoid, the possession of amphi- or opistho-coelous vertebrae, do not mean much, and certainly do not forbid the notion that all the recent Urodela are the offspring of one common generalised stock which inhabited the northern portion of the globe. Nothing is gained by hiding the solitary European species of the essentially American genus Spelerpes under the name of Geotriton. It is a Spelerpes in all characteristic points. Speaking broadly, each of the three principal sub-families of Salamandridae is characteristic of a sub-region; the Salamandrinae of the Western Palaearctic, the Plethodontinae of the American, while the Amblystomatinae are chiefly Asiatic, at least so far as diversity of genera is concerned.

Fam. 1. Amphiumidae.–Without gills in the perfect state. The gill-clefts are in a vanishing stage, being either reduced to one pair of small holes or being altogether absent. The maxillary bones are present. Teeth occur in both jaws; those of the vomers form transverse rows. The vertebrae are amphicoelous. The fore-limbs and hind-limbs are present, but small. The small eyes are devoid of lids.

This family is now represented by two genera, with only three species, found in the United States and in Eastern Asia.

Cryptobranchus.–The limbs are functional, with four fingers and five toes. The outer digits and the sides of the limbs are bordered with folds of skin. The head and body are stout and depressed; the tail is short, laterally compressed, and provided with a fin. The skin is very glandular and slimy, and forms a thick, irregularly-shaped fold along the side of the body.

C. (Menopoma) alleghaniensis.–The gill-clefts are normally reduced to one pair, individually to the left cleft, the right closing up. There are, however, four branchial arches and vessels. The general colour is brown or grey above, sometimes with darker patches, lighter below. The "Hellbender" reaches a length of nearly 18 inches (about 46 cm.), is entirely aquatic, and is apparently restricted to the rivers and streams of the mountainous districts of the Eastern United States. It is very voracious, living on worms and on fish, being much disliked by the fishermen, as it takes the angler's bait, and destroys great quantities of the valuable food-fish Coregonus albus. Although rather common and easily kept, its larvae still remain unknown.

C. japonicus s. maximus.–The Giant Salamander of Japan differs from its American relation in one essential point only, namely, by the absence of gill-openings and of the modifications of the branchial apparatus connected therewith. It has but three branchial vessels, and the skeletal arches are reduced to two. It lives in Japan and in China, from 600 to 4500 feet above the level of the sea, in small streams of mountain-meadows. It feeds upon fishes, Amphibia, worms, and insects. It is easily fished with the hook and is eaten by the Japanese.

The first living specimen was brought to Europe in 1829 by Th. von Siebold, its discoverer. It grew within a few years from 1 foot to 3 feet in length, and died in 1881, at least fifty-two years old. Another specimen lived in the Hamburg aquarium for fourteen years, during which time it is said to have grown 36 cm. (more than 14 inches), having attained a length of nearly 4½ feet, or 134 cm. The largest specimen known measures 159 cm = 5 feet 3 inches.

The life-history of this species is still imperfectly known. Japanese picture-books contain drawings of the adult and of larvae, the latter showing three pairs of fringed external gills. Young specimens of 16 cm. length have already lost the gills, but still retain a cleft on either side of the neck, in the shape of a horizontal slit, and this is soon after closed up by the skin.

The best account has recently been given by Sasaki.^[46] According to him the Giant Salamander leads a solitary life, concealed in dark places, under rocks in swift-flowing, thickly shaded small brooks of clear and cold water.

The animal may be easily captured with a fish-hook, baited with a fish, frog, or several earth-worms, and tied to a string a few feet in length. This is thrust by the aid of a small bamboo-stick into the salamander's retreat. The string is not tied to the stick, but the point of the loaded hook is forced into one end of it, far enough to keep it in place while this end of the rod is pushed under the rock. When the bait has been thus brought near the salamander, any bite will be instantly felt through the rod. The latter is then withdrawn as quietly as possible, the hook and bait being left. As soon as a jerk of the string is noticed, a pull is made, which generally ends in the capture of the unfortunate animal. If the first pull should fail, the bait is replaced as before, and a second opportunity is offered, which the unwary creature accepts as readily as the first. The fisherman, having obtained one bite, is sure of ultimate success, as the salamander does not learn by experience to refuse the proffered morsel. When captured, it emits a peculiar slimy secretion, having an odour much like that of the leaves of the Japan pepper (Xanthoxylon peperitum). This secretion hardens into a gelatinous mass after a short exposure to the air.

Temminck and Schlegel state that the act of inspiration is ordinarily performed once every 6-10 minutes. This is true for specimens kept in tubs; but Sasaki is inclined to think that they perform this act less frequently in their native brooks. The eyes are so small that they are obviously of little importance; the salamanders capture their prey not by pursuing, but by waiting for its near approach, whereupon they seize it with their teeth by a swift lateral movement of the head. The eggs are said to be laid in August and September, and they form a string resembling a rosary. Each egg floats in a clear fluid, inclosed in a bead-shaped gelatinous envelope, and this is connected with the next by means of a comparatively small string. The egg measures about 6 mm. by 4 mm., and is yellow everywhere except at the upper pole, where it is whitish. All attempts to make Cryptobranchus breed in captivity have failed hitherto, owing no doubt to the difficulty of obtaining the cool temperature of its mountain streams. Sasaki's smallest specimens measured 19 to 20 cm. These had three pairs of very short branchial processes, from 3 to 5 mm. in length, attached just inside the branchial orifice. Each process was somewhat flattened and tapering, most of them still with branchlets. In another specimen, 20.5 cm. in length, the gills had almost wholly disappeared, but the branchial slits were still visible. One of 24.5 cm. length showed no trace of gills, and the branchial orifice was completely closed, but still marked by a light streak.

Amphiuma means s. tridactyla.–The limbs are very much reduced, and end in two or three little fingers or toes. Just in front of the fore-limbs lies the pair of small gill-clefts, each guarded by two flaps of the skin. There are four branchial arches. The general colour of this eel-shaped creature is black, lighter below. The head is covered with numerous pores, arranged in several rows, which unite in the region of the neck, so that only two rows extend along the sides of the body. It reaches a length of three feet, and lives in swamps or muddy waters, for instance in the ditches of rice-fields, burrowing occasionally in the mud, feeding on crayfishes, molluscs, small fishes, etc. It is confined to the south-eastern States of North America, from Carolina to Mississippi. According to Davison,^[47] copulation takes place in May. The rather hard-shelled eggs are deposited in the following August or September, and are connected by a twisted cord. The female lies about them in a coil. The embryos, which are hatched in the month of November or December, have well-developed external gills. By the following February they have reached a length of from 68 to 90 mm. (about 3 inches), living in damp localities under rocks or rooted stumps, and have already lost their gills. The legs are said to be relatively longer than they are in the adult.

Fam. 2. Salamandridae (Salamanders and Newts).–Without gills in the perfect state. Maxillaries are present. Both jaws are furnished with teeth. The eyes are protected by movable lids, except in Typhlotriton. Fore- and hind-limbs present, although sometimes very much reduced.

To this family belong by far the greater number of tailed Amphibia. They have been, for the sake of convenience, grouped into four sub-families, the determining characters of which are all internal and of comparatively slight importance. Little better is the division into Mecodonta, with the teeth of the palate in two longitudinal rows diverging behind and inserted upon the inner margins of the two palatine processes, which are much prolonged posteriorly, and Lechriodonta, in which the series of palatal teeth are restricted to the posterior portion of the vomers and form either transverse or posteriorly converging rows.

Sub-Fam. 1. Desmognathinae.–Comprising only three genera, with five species, in North America. Five toes.

Desmognathus.–The tongue is attached along the median line, free behind, oval in shape. Three species in the eastern half of the United States. D. fuscus is one of the lungless Urodela, for which condition see p. 46. The skin is nearly smooth; parotoids prominent, gular fold strongly marked. General colour above, brown suffused with pink and grey, sometimes with a dark lateral band; under parts mottled brown. The vomerine teeth are frequently absent. Total length, about 4 to 5 inches. They live, carefully concealed in the daytime, under stones in or on the edge of the banks of little mountain streams. The eggs are laid in two long strings, and are wrapped round the body of the female like a rosary, the female having resorted to a hollow in the mud, below a stone or other suitable place. The outer envelope of each egg tapers out into a short stalk, and the several stalks all converge, or are glued together into one common knot, "much like a bunch of toy balloons held in the hand of a street vendor." The egg is said to be meroblastic. The larvae seem to remain in the egg until they are nearly adult, and they emerge at midsummer, with the gills already much reduced. The complete metamorphosis takes place in the autumn of the same year. These little newts can, according to Wilder,^[48] be collected all the year round, in Massachusetts from March to December, except during the time of deep snow. They are nocturnal and are easily kept.

Thorius pennatulus, from Orizaba, Mexico, the only species, is noteworthy for its extremely large nostrils, and for the tongue, which is supported by a central pedicle, free all round, and ending in a thick knob, which can probably be protruded. The limbs are weak, and the digits are also much reduced. Total length, under 2 inches, or 50 mm.

Typhlotriton spelaeus, of the Rock House Cave in Missouri, is blind, the eyes becoming concealed by the skin during metamorphosis, when the gills are lost.

Sub-Fam. 2. Plethodontinae.–The five genera of this almost entirely American sub-family (only one species of which, Spelerpes fuscus, occurs in Europe) can be distinguished as follows:–

Spelerpes.–Except in a few species the limbs are well developed and possess 4 fingers and 5 toes, which are either free or webbed. But in the Colombian S. parvipes, still more in S. lineolus of Orizaba and S. uniformis of Costa Rica the limbs and digits are reduced to mere vestiges, and are practically without function, the body, with the extremely long tail, having assumed a wormlike shape. The young of many, if not all, species have a pair of short balancers below each nostril; in the adult these organs are reduced to little swellings or lost completely. Several species are lungless, see p. 46.

The geographical distribution of this genus, of which some twenty species are known, is very remarkable. The majority live in Mexico and in the United States, a few are found in Colombia and Northern Peru (S. altamazonicus and Plethodon platense being the only Urodeles hitherto recorded from south of the equator), one in Hayti (S. infuscatus), two (S. subpalmatus and S. uniformis) in Costa Rica, and S. fuscus in Europe.

S. bilineatus is a little newt under 4 inches in length–60-95 mm.–found in the Atlantic States. It is brownish-yellow above, with a black lateral line extending from the eye to nearly the end of the tail. The under parts are bright yellow. It lives on land, in damp places, concealed during the daytime under stones or old trees, whence it emerges after a rain or in the dusk of evening.

According to H. H. Wilder,^[49] "the eggs are deposited in May and June in a single layer upon the lower side of submerged stones, each batch containing 30 to 50 eggs. The stones which are suitable for this purpose must be in the form of an arch, allowing the water to flow beneath. They are generally in the more rapidly flowing portions of the brook, but the depth of water must be such that the eggs are at all times entirely submerged. They are attached to the stone by gelatinous threads, proceeding from the outer envelope, and although they are generally contiguous, they are each attached separately." The eggs are holoblastic. The larvae hatch early and continue for a long time in the larval state, probably two or three years.

S. porphyriticus s. salmoneus.–Yellowish-brown or purplish-grey above with tiny darker dots and markings. The sides of the body are salmon-coloured, with a tinge of yellow. The under parts are whitish, turning into salmon-pink on the tail. This beautiful newt reaches about 6 inches in length and has a very moist, slimy skin, which, combined with the lively motions of the creature, make it as slippery as an eel. It is found in the Alleghany range, from New York to Alabama.

Specimens which I am keeping prefer the wettest part of the cage, where they lie concealed in the moss and mud, leaving their hiding-places at night in search of insects. One of them escaped into the greenhouse and was discovered after nine months, having established its permanent home in a cleft between mossy stones: when the sweepings of a butterfly-net are emptied near its hiding-place it peeps out and with a flash of its long, forked, white-coloured tongue it secures its prey. Occasionally it goes into a tank, when it swims with rapid, undulating motions, the limbs being laid back and remaining inactive; it sometimes rises to the surface to emit and to take in air, but, although mostly resting half in the water, upon a rotten stump, it often lies for hours at the bottom without stirring. When kept in dry surroundings, the skin soon dries and wrinkles, and the animals show every sign of suffocation and general discomfort. The respiration of this lungless species by means of rapid movements of the throat is very limited, most of the necessary oxidisation of the blood being effected through the skin.

S. fuscus.–This, the only European species, is thoroughly terrestrial. It is found in the mountains bordering the Gulf of Genoa, and in Sardinia. Its total length remains under four inches. The smooth, very delicate and easily broken skin is brown above, light below, and speckled with lighter and darker markings. Below each nostril is a slight swelling, the remnant of the cirri or balancers common to the young of many species. It lives in shady surroundings, under stones, in old trees and in limestone-caves, glued to the walls with spread-out toes, belly and tail, quietly waiting for insects and spiders which it catches by flashing out the long tongue.

According to J. Berg,^[50] it keeps well in cool, moist and well-ventilated places. It lives on flies, small beetles, and maggots; ants are also taken at once, probably owing to their lively movements, but a few minutes later the newts roll about in spasms and soon die. Towards the end of March one of Berg's specimens gave birth to four young, which were 36 mm., or nearly 1½ inches long, and differed from the adult only by their exceptionally large nostrils, thereby resembling the Mexican Thorius. The little ones shot out their tongues about 10 mm., feeding on Aphides.

Manculus.–The two species of this genus live in Carolina and Florida. M. quadridigitatus is a very slender, graceful little animal, about 3 inches in length, the long and thin tail being considerably larger than the rest of the body. Yellowish, minutely speckled with brown above and on the sides, greyish-white below. Life entirely terrestrial.

Plethodon.–About seven species in North America. This genus has given its name to that of the subfamily, which might with more reason be called Spelerpinae.

P. glutinosus is slaty or bluish-black, with small whitish specks, especially on the sides of the trunk, where they are large and often confluent. The skin is smooth and shiny. Total length about 5 inches, half of which belong to the tail. Holbrook considered this as one of the commonest of the North American newts, and mostly widely distributed, from Ohio to the Gulf of Mexico. It usually lives concealed under stones, but prefers fallen trees, probably on account of the insects upon which it preys. When taken in the hand it gives off a great quantity of slime.

P. erythronotus extends into Canada and is much smaller. Brown or grey above, mostly with a broad, reddish-brown band over the head, back, and tail. The under parts are white, with grey and brown specks.

Autodax s. Anaides.–The large tongue is attached along the median line. The jaws are furnished with few, but surprisingly large, knife-shaped teeth, about ten in the upper and fewer in the lower jaw. The small teeth of the vomers form a chevron-shaped series behind the choanae, those of the parasphenoid stand in one elongated patch. The tail is round; number of toes, five. Three species in Western North America, from California to Oregon.

A. lugubris.–The eyes are very large and prominent. The upper jaw shows a peculiar recess on either side for the reception of the large lower teeth. The skin is smooth, devoid of parotoid glands, but has a strong gular fold. The upper parts are dark brown or lead-coloured, with whitish dots on the sides; under parts white. Total length some 6 inches, about half of which belongs to the tail. The fingers and toes are very rich in subcutaneous venous sinuses.

The habits of these creatures are in many respects peculiar. Van Denburgh^[51] says of A. iecanus "that it usually moves quite slowly, moving one foot at a time, but is capable of motion surprisingly rapid for a salamander. When moving rapidly, it aids the action of its legs by a sinuous movement of its whole body and tail. The latter is prehensile. Several individuals, when held with their heads down, coiled their tails around my finger, and, when the original hold was released, sustained themselves for some time by this means alone. One even raised itself high enough to secure a foothold. This animal's tail is also of use in another way. When caught, it will often remain motionless, but if touched, will either run a short distance with great speed, or quickly raising its tail and striking it forcibly against the surface on which it rests, and accompanying this with a quick motion of its hind-limbs, will jump from four to six inches, rising as high as two or three."

Ritter and Miller^[52] have made extensive observations on the life-history of A. lugubris. When wishing to pass from the hand to the table, the creature will frequently execute a well co-ordinated spring and alight on its feet some distance away, instead of falling over the edge in the typical salamander-fashion. This species is nocturnal and entirely terrestrial, and seems to be indifferent even to proximity to water. Rotten stumps and logs are the habitations preferred, and wherever these occur in the region about San Francisco Bay, even though at the places remotest from water, specimens are sure to be found.

The eggs are laid in a hollow under ground, and the female seems to remain curled around them until they are hatched, which takes place in two or three weeks. The specimen observed by Ritter and Miller laid 19 eggs. Each was contained in a gelatinous capsule 6 mm. in diameter, and was firmly anchored to a clump of earth by a narrow peduncle about 8 mm. long. The embryos developed very large gills, each being composed of three broad membranous lobes, the latter being thin and delicate, much expanded, highly vascular and widely confluent at their bases, so that the gills of each side really form one three-lobed mass. Their dorsal surfaces are applied to the inner surface of the egg-capsule. The amount of food-yolk is considerable. The whole larval life is passed through within the egg. Before the young is hatched the gills wither and cease to be functional, and the gill-slits close up. The tail is round, and shows no indication of a fin at any time during the larval period. Newly hatched individuals appeared much distressed when put into water, and were quite unable to swim. They immediately sank to the bottom and remained there until they were removed. The integumentary sense-organs, so well developed in the aquatic larvae of Urodeles, are entirely wanting. When hatched the young creature is about 32 mm. long; its general colour is blackish-grey, finely sprinkled with bluish-silver. During the second year this garb is changed to the dusky brown of the adult, and the fine silver speckling is replaced by much larger and less numerous yellow spots.

Although one of the most terrestrial of Urodeles, this species is lungless, but the skin remains delicately smooth and moist throughout life. According to the observers quoted, the pharynx plays an important part in respiration. From 120 to 180 or even more vibrations are made by the throat in a minute, and in some cases these movements are grouped into series of about 20 to 25 extremely rapid vibrations, with periods between each two series.

Subfam. 3. Amblystomatinae.–Composed of seven closely allied genera, the distinguishing characters of which are the grouping of the palatal teeth and the number of the toes, which varies between 4 and 5. The geographical range of the subfamily extends over the whole of North America and Mexico and over the whole of Northern Asia, from Kamtchatka and Japan westwards to the Ural, and southwards into China. The occurrence of one species, Amblystoma persimile, in the mountains of Siam, makes it highly probable that other species and genera exist in the hitherto unexplored intervening countries.

Boulenger gives the following synopsis:–