The "Tejus" frequent forests and plantations, and are carnivorous. Their strength and swiftness enable them to catch all kinds of animals, from insects and worms to frogs, snakes, mice, and birds. As they take chickens and eggs from the farms they are considered noxious, and they are frequently hunted down with dogs for the sake of their flesh, which is regarded as good to eat. They defend themselves with lashing strokes of their long tail and with their powerful jaws. They retire into burrows, and they deposit their hard-shelled eggs in the ground. In captivity they can easily be kept on meat.

Dracaena guianensis of the Guianas and the basin of the Amazon has the lateral teeth transformed into regular large molars, with broad and rounded crowns. The tail is strongly compressed, with a double, denticulated keel. It seems to be semi-aquatic, and, to judge from the teeth, herbivorous.

Ameiva and Cnemidophorus, with many species chiefly in tropical America, have laterally compressed bi- or tri-cuspid teeth. The skin forms a double fold on the neck, and is covered on the upper surface of the body with very small scales; those on the ventral surface are large, and arranged in regular rows. Most of the species are small, under one foot in length, and are extremely pretty, very active, timid, and mainly insectivorous.

C. sexlineatus is one of the few species of Cnemidophorus which inhabits the southern half of North America. Like all its relations it has the appearance of an ordinary lizard (Lacerta). The head is dark brown. A purple or brownish band extends over the back and tail, bordered on either side with three golden-yellow longitudinal lines. The flanks are brown, the under parts bluish white. The iris is golden, and the inner margins of the lids are bordered with a narrow band of bright yellow. This species is a very fast runner, and frequents dry and sandy places. Its total length amounts to about 10 inches.

Fam. 11. Lacertidae.–Pleurodont Old-World Lizards, without osteoderms on the body, and with the supratemporal regions roofed over by osteoderms.

The limbs are always well developed, and have five fingers and five toes, always provided with sharp claws. The skin covering the head forms large shields, mixed with small scales; most of which, especially the shields, contain dermal ossifications. These frequently fuse with the underlying bones of the top of the skull.

The latter is always well marked off from the neck. The postorbital arch is complete. The temporal region is completely roofed over by bones dorsally, chiefly owing to the size of the postfrontal (Fig. 142, pt.f₂) which fills the space between the parietal and the squamoso-postorbital bridge, thus abolishing the supra-temporal fossa. The squamosal is very small, placed between the postfrontal (pt.f₂), the lateral occipital and the supratemporal. The large jugal and the quadrate are not connected with each other. The columella cranii is well developed. The infra-orbital fossae are surrounded by the palatines, pterygoids, ectopterygoids, and maxillaries. The palatines and pterygoids remain separated in the middle line. The pterygoids frequently carry little teeth. The other teeth are typically pleurodont, hollow, slightly curved, and bi- or tri-cuspid.

The skin covering the body, the legs, and the tail is devoid of osteoderms. The scales on the dorsal surface vary much in size, from large, strongly keeled scales to tiny granulations. Those of the ventral surface are large, broader than long, and are frequently arranged in regular transverse and longitudinal rows. The tail, generally long and pointed, is very brittle. All the sense-organs are well developed. The tympanum is exposed. The tongue is deeply bifurcated, narrow, flat, and covered with scale-like papillae.

Various Lacertidae, especially some of those genera which live and dig in the sand, have a transparent disc in the middle of the lower eyelid, so that they can see while the eye itself is protected. This is for instance the case in some specimens of the Indian and African Eremias. In the Indian genus Cabrita the transparent disc is very large, and in Ophiops, which inhabits sandy stretches from North Africa to India, the lower eyelid is fused with the rim of the much-reduced upper lid, and forms a large transparent window.

The Lacertidae or True Lizards comprise nearly twenty genera, with about one hundred species, and are typical of the Old World, being found in Europe, Asia, and Africa, but not in Madagascar nor in the Australian region. They are most abundant in Africa. Their northern limit coincides fairly closely with the limit of the permanently frozen under-ground. This is indicated in the map (Fig. 143) by the dotted line. All the Lacertidae live upon animal food, chiefly insects, and after them worms and snails; but the larger lizards take what they can master, frequently other lizards, and even younger members of their own kind. Many of them love sugar, which they lick, and all require water. They are all terrestrial, preferring, according to their kind, such localities as yield them their particular food.

Sunshine and warmth make a marvellous change in the same individual, which on dull, rainy, or cold days lies in its hole, or shows only sluggish movements. Their sense of locality is great, or rather each individual inhabits one place, of which it knows every nook and corner, cranny, tree, and bush. It has its favourite hole to sleep in, a stone, the branch of a tree, or a wall to bask upon, and when disturbed or chased it makes with unerring swiftness for a safe spot to retire into. The same lizard, when once driven away from its own locality, seems to lose all its presence of mind, flounders about, and is comparatively easily caught. Most lizards are extremely curious, although shy, and this state of their mind can be made use of by those who want to catch them without injury, and above all without getting the animal minus the brittle tail. This safe way of catching lizards consists in taking a thin rod with a running noose of thread at the end, in drawing the latter over the lizard's head, and then raising it. The little creature does not mind the rod in the least; on the contrary, it watches it carefully, and often makes for the thread. The boys in Southern Italy have improved upon and simplified this mode of catching lizards by bending the end of a wisp of grass into a noose, and covering the latter over with a thin film of saliva. The shiny film, like a soap-bubble, is sure to excite the curiosity of the creature. The late Professor Eimer^[165] refers to this practice as carried out by the children of two thousand years ago, and he sagaciously explains that the beautiful statue of the so-called Apollo Sauroctonos represents a boy who is in the act of noosing the little lizard on the tree.

Lacerta.–A row of enlarged scales forms a distinct collar across the ventral half of the neck, in front of the chest. The scales on the back are much smaller than those on the tail, which is long, round, and pointed. The digits have smooth, tubercular lamellae on the under surface. Femoral pores are well marked. This genus, with about twenty species, ranges through Europe, Northern and Western Asia, and Africa north of the Equator.

L. vivipara, the Common English Lizard, has a very wide range, through Northern and Central Europe and Siberia to the Amoor country and the Island of Saghalien. It occurs throughout Great Britain, even in Ireland, where it is the only species of reptile, occurring, for instance, in the County of Meath and in the south-eastern counties, e.g. Waterford. It does not occur south of the Pyrenees or south of the Alps. The supra-ocular and the supraciliary scales are in contact with each other, not being separated by a series of little granules. Normally there is a single postnasal and a single anterior loreal shield. The ventral scales are arranged in six or eight longitudinal series, of which the second series on each side from the median ventral line is the largest. The coloration of this species is subject to much variation. The general colour of the adult is brown or reddish above, with small darker and lighter spots; many specimens have a blackish vertebral streak and a dark lateral band edged with yellow. The under parts are orange to red in the male, with conspicuous black spots; yellow or pale orange in the female, either without or with scanty black spots. The newly-born specimens are almost black. The males are slightly smaller than the females; males of a total length of 6 inches, and females 7 inches long, may be considered rather large specimens.

This lizard is, as the specific name implies, viviparous, i.e. the six to twelve young burst the eggs immediately after they have been laid; sometimes the mother has to retard the laying, in which case the young are born free. The female does not make a nest, but simply deposits her offspring on the ground and leaves the young to their fate. For the first few days the little ones, which scarcely measure three-quarters of an inch in length, remain almost motionless between leaves or in cracks of the ground, and they do not take any food. They grow, however, quickly, living upon the remains of the yolk which has slipped into their body. Their first food consists of Aphides and similar tiny insects.

The Common Lizard prefers moist localities and is very hardy. It extends northwards to Archangel, and in the Alps it ascends to nearly 10,000 feet above the level of the sea. However, on the approach of the cold season, in the month of October, it withdraws into its winter quarters, frequently in company with many of its own kind.

L. agilis, the Sand-Lizard, has nearly the same wide range as L. vivipara, except that it does not go so far north and does not extend eastwards beyond Central Siberia. It is absent in Ireland and Scotland, while in England it is restricted to the southern half.

The characters which distinguish the Sand-Lizard from L. vivipara are few, although the majority of the specimens of either kind are very distinct in their coloration, and L. agilis is strictly oviparous, depositing its eggs in the ground, under leaves, in heaps of weeds and similar places. The Sand-Lizard has usually a single postnasal and two superposed anterior loreals, the three shields forming a triangle. The temples are covered with flat scales, two or three of which are enlarged and in contact with the parietals, but there is no tympanic scale.

The coloration is subject to much variation, local as well as individual. As a rule the Sand-Lizard gives the impression of being striped longitudinally, the striation being caused by rows of dark and white spots and patches along the sides of the back, flanks, and tail. In the male a more or less pronounced green, in the female brown and grey are the prevailing ground-colours. A typically coloured male during the breeding season is grass-green on the sides and suffused with green on the yellow under parts; the sides are dotted with black, with whitish eye-spots. The under parts are spotted with black. The adult female is brown or grey above, with large dark brown, white-centred spots, which are arranged in three rows on each side. The under parts are cream-coloured, with or without black specks. The young are grey-brown above with white, black-edged spots; the under parts are whitish. Total length of the adult up to 8 inches. The male is a little smaller than the female but has a relatively longer tail, a little less than half the total length.

The Sand-Lizard is easily kept in captivity, and lives for years if allowed a variety of food and proper places to hibernate in. It pairs in the spring, in England in May or June; the white, parchment-like eggs, numbering five to eight, are hatched in the following July or August.

L. viridis, the Green Lizard, inhabits Southern and Middle Europe and South-Western Asia. The general colour of this beautiful lizard is emerald-green above, changing into greenish yellow on the flanks and into yellow on the belly. The throat, especially in the males during the breeding season, is blue. The upper parts are frequently speckled with black. The young are brown or green above with one or two yellowish lateral stripes, which persist in some adult females. There are usually two superposed postnasal shields. The semilunar collar on the neck is well pronounced, and there is usually a distinct gular fold. The tail is often very long, especially in the males, sometimes nearly three-quarters of the total length, which in very large males reaches 16 or 17 inches. The females do not quite reach this length.

The Green or Emerald-Lizard prefers rocky localities, from the sea-level, as for instance in Jersey, up to a height of several thousand feet. It is extremely swift and can climb trees, which it sometimes resorts to when chased. When hard pressed it takes tremendous leaps down to the ground, marvellously enough without injury to body or tail, which latter is otherwise very brittle. They pair in the spring or early summer after much fighting between the males; the eggs, to the number of about ten, are whitish and are deposited a month later. The young are hatched after another four weeks.

This beautiful lizard does not keep well in captivity, although it becomes very tame; it eats meal-worms, snails, earth-worms, and insects, especially butterflies, but it sickens after the first winter even if it has been allowed to hibernate.

In Portugal and Spain L. viridis is represented by a slightly different kind, L. schreiberi, the chief interest of which lies in the fact that it approaches L. ocellata in several respects. The occipital shield is large and is usually broader than the interparietal. The dorsal scales are smaller, and there are eight well-developed rows of ventral scales. Instead of being uniformly green, the upper parts are usually spotted and vermiculated with black; sometimes, especially in the females, the black spots have a white ocellus in the centre. The under parts are yellowish, with or without black spots. The throat is blue. The young look very different. They are olive-brown above with large yellow, or bluish-white, black-edged ocelli on the side of the head and body.

Other forms, perhaps of sub-specific rank, approaching L. ocellata, occur in the Balkan Peninsula, where, for instance in Dalmatia, the typical L. viridis attains its most beautiful development.

L. ocellata, the Eyed Lizard, inhabits Spain and Portugal, extending northwards into the South of France and into the Riviera, southwards into Morocco and Algeria; these southern forms (L. pater and L. tangitana) approach L. viridis. The Eyed Lizard is green or dark olive above, with black or yellowish dots, which are sometimes combined into a kind of network pattern. The under parts are uniformly greenish yellow. The sides of the body are adorned with about two dozen blue, black-edged spots or "eyes." The intensity of the blue and the depth of the green ground-colour vary much according to sex, time of the year, and state of health. Males during the breeding season are most beautiful and brilliant. The occipital shield is broad; there are two superposed nasal but no tympanic shields. The supraoculars are separated from the supraciliaries by a series of granules. The collar is well marked, but not the gular fold. The dorsal scales are minute and granular; the ventral shields are arranged in eight or ten longitudinal rows.

The "Eyed Lizard" reaches a considerable size, especially the males, which develop a very strong and thick head, and are much more robust and powerful than the more slender females. Old males reach a length of 2 feet, two-thirds of which length belong to the tail; but the latter varies much, even if it has never been broken and renewed.

The Eyed Lizard keeps extremely well in captivity, and in this respect is unlike the Green Lizard. A case has been recorded of its living thirteen years. This species is very intelligent. Although at first ferociously wild and biting furiously, these lizards soon become tame and take food regularly. One of my own, a half-grown male from Northern Spain, about one foot in length, made its home in a little niche of the greenhouse-wall, whence it emerged regularly to take the offered food from my hand. It soon knew the whole place thoroughly, making use of the creepers whilst scaling up to its retreat, jumping over certain gaps, descending to the ground at certain spots, basking on certain stones, invariably in the same methodical way. In the month of October it retires into the ground on the coolest side of the greenhouse, and although the latter is well warmed, the lizard remains invisible until the next February or March, when on some fine day it is rediscovered basking upon exactly the same stone where it had been seen five months before. The only drawback in connexion with keeping this kind of lizard in company with other creatures is their voraciousness; since large, fully adult specimens attack and eat any other small lizard, slow-worm, or snake they can find. They also take mice. The eggs are often deposited in hollow trees.

L. muralis, the Wall-Lizard, is very common in Southern Europe, Asia Minor, and Northern Africa. Northward it extends into Belgium and into South Germany. In the Iberian Peninsula it ascends up to 5000 or 6000 feet above the level of the sea. This graceful little creature, with an average length of 6 to 8 inches, is easily recognised by the series of granules between the supraocular and supraciliary scales and usually by having only six rows of ventral scales. The great variety in coloration has given rise to the establishment of many races, varieties, and sub-species. In the typical forms the upper parts are brown or greyish, with blackish spots or streaks, sometimes with a bronzy greenish sheen. The under parts are white, yellow, pink, or red, either uniform or, especially in the males, with large black spots. The lateral rows of ventral shields are frequently blue. The colour-varieties are almost endless. One of the most noteworthy is that described as var. coerulea by Eimer; this, confined to the Faraglione Rocks near Cápri, is blackish above, like the rock, and sapphire-blue below. Similarly coloured specimens, var. lilfordi, occur on some of the rocky islets of the Balearic Isles.

The Wall-Lizard deserves its name, since in the Mediterranean countries there is scarcely a wall on which these active lizards do not bask or run up and down, often head downwards, in search of insects. They are oviparous. The hibernation is short and not very deep, since these lizards can sometimes be seen basking on sunny winter days before their regular appearance in the early spring.

Psammodromus, with a few species in South-Western Europe, notably in the Iberian Peninsula and in North-Western Africa, has no distinct semilunar collar, but has a short fold in front of each arm. The back is covered with large, rhombic, strongly keeled and imbricating scales. The lateral scales pass gradually into the ventrals, which are smooth and arranged in six longitudinal rows.

P. hispanicus is bronzy brown above, with small black and white specks, and with one or two longitudinal streaks on each side. The under parts are white. Total length about 5 inches. Although also found inland, this species prefers sandy dunes, studded with prickly and scanty vegetation. It runs very fast and digs itself rapidly into the sand when pursued. When caught it either utters a faint cry like "tsi-tsi," or it feigns death. The pairing takes place in June; half-a-dozen eggs are laid about eighteen days later, deeply imbedded in the warm sand, and they are hatched in eight weeks. The eggs are said to grow^[166] after they have been laid from 13 by 7 mm. to 17-20 by 10-11 mm. The newly hatched little creatures measure about 2 inches in length, more than half of which belongs to the tail.

P. (Tropidosaura) algirus has the same range as P. hispanicus, but grows to 10 inches in length, and is much more beautifully coloured. The upper parts are bronzy brown with one or two golden, dark-edged, lateral streaks; the under parts are whitish; the male has one or more blue-eyed spots above each shoulder.

Acanthodactylus is distinguished by the laterally fringed digits. This genus ranges throughout Northern Africa to the Punjab. One species, A. vulgaris, extends into Spain and Portugal. The dorsal scales are small and almost smooth, but those on the tail are strongly keeled; the ventrals are much broader than long, and are arranged in eight to ten rows. The fringes on the digits are but feebly developed in the shape of lateral denticulations. The adults are grey-brown with faint longitudinal stripes, and with more conspicuous black and pale spots; in the breeding season larger blue-eyed spots appear on the sides near the limbs. The tail is often pink, especially on the under surface. Total length about 7 inches.

Fam. 12. Gerrhosauridae.–Pleurodont African Lacertidae with osteoderms on the head and body.

This family is intermediate between the Lacertidae and the Scincidae. The tongue is constructed like that of the Lacertidae, but is only feebly nicked anteriorly. Dermal ossifications roof over the temporal region, and femoral pores are present. On the other hand, the osteoderms, which cover the whole body, are in their structure and arrangement typically Scincoid. The tail is long and fragile. A lateral fold is usually present. The limbs are sometimes reduced to useless stumps. The few genera and species of this family are strictly confined to the African sub-region, being found in the whole of Africa south of the Sahara, and in Madagascar.

Gerrhosaurus, with a strongly developed lateral fold and complete limbs, occurs in Africa. G. flavigularis, of South Africa, has a total length about one foot.

Tetradactylus, of South Africa, has also a strong lateral fold, but the limbs are either very short and pentadactyle (T. seps), or tetradactyle, or they are minute pointed stumps, as in T. africanus.

Fam. 13. Scincidae.–Pleurodont lizards with strongly developed osteoderms on head and body, with very feebly nicked, scaly tongue, with complete cranial arches, and with separated premaxillaries.

The temporal region is covered over, as in the Lacertidae, with strongly developed, bony, dermal ossifications. Similar osteoderms underlie the scales which cover the body and tail. The tongue is relatively short, not forked behind, and but very feebly nicked at the tip; it is covered with scale-like papillae. Femoral pores are absent.

All the Skinks prefer dry, sandy ground, in which they not only burrow, but move quickly about, either for protection or in search of their animal food. In connexion with this sand-loving and at least temporary subterranean life stands the frequent reduction of the limbs. Every stage from the fully developed and functional pentadactyle limb to complete absence of limbs is represented. There are species within the same genus with five, four, three, or two fingers or toes. There are Skinks without fore-limbs, but with vestigial hind-limbs, and vice versa. The interesting point is that these reductions do not indicate relationship within the family, but have happened independently. They are impressive illustrations of convergent retrogressive evolution.

Ablepharus, widely distributed in the Old World, has the lower eyelid transformed into a transparent cover, which is fused with the rim of the reduced upper lid, exactly as in the Lacertine genus Ophiops.

All the Scincidae seem to be viviparous, some of them, e.g. Trachysaurus, in the strict sense of the word, since the hard or parchment-like egg-shell has been dispensed with.

The family contains about four hundred species, which have been arranged in nearly thirty genera, many of them on fanciful grounds. The family is cosmopolitan, but reaches its greatest diversity in numbers and forms in the tropical parts of the Old World, especially in the Australian region, inclusive of the islands of the Pacific. America, notably South America, has the smallest number.

Trachysaurus, with one species, T. rugosus, inhabits the whole of the Australian continent. It is easily recognised by the large and rough scales, and the short and broad stump-like tail. It is dark brown above with yellowish irregular markings; the under parts are yellowish, marked with brown. Embryos of this species have yellow transverse bands on the back, but these often fade away before birth. The creature is strictly viviparous, the egg-membrane being very thin, and the two or three embryos are ripened in uterus-like dilatations of the oviducts. The period of gestation is about three months, and the birth takes place, in South Australia, about April. According to Fischer^[167] this species, which is often in the market, is easily kept. It requires warmth, sand and stones for basking, and water, in which it soaks itself preparatory to the shedding of the skin, which takes place half-a-dozen times in the year, and is a slow process, requiring eight to ten days. The food consists chiefly of worms, lizards, and snakes, but meat, cabbage, and lettuce are also taken. The total length is about one foot.

Cyclodus s. Tiliqua, of Australia, Tasmania, and the Malay Islands, has stout lateral teeth with spherical crowns. The imbricating, cycloid scales of the body and the rather short but pointed tail are quite smooth and shiny. C. gigas, of New Guinea and the Moluccas, reaches a length of nearly 2 feet. The general colour is brownish yellow, with broad, dark bands across the body and tail.

Scincus, of North Africa, Arabia, Persia, and Sindh, has pentadactyle limbs, with laterally serrated digits. The eyelids are well developed, but the ear is hidden under scaly flaps. S. officinalis, of the Sahara and of Egypt, grows to about 8 inches in length. The snout is peculiarly shaped, cuneiform. The eyes are very small. The scales of the body are perfectly smooth; the sides of the belly are somewhat angular. The whole shape of the creature, the scales, and the digits are adapted to burrowing and moving quickly through the loose sand. The general colour is yellowish or brownish above, each scale with small brown and whitish spots; the under parts are uniform whitish. The young are quite beautiful, being uniform pale salmon-coloured above, silvery white below. When a little older, yellow spots appear on the flanks and grey bands across the back. These Skinks live in the absolutely dry reddish-yellow sand of the desert, in which they may almost be said to swim about, so swift and easy are their movements. They live on insects, while in their turn they are eaten by snakes, and above all by the Varanus lizards.

Of Mabuia with about forty species, in the whole of Africa, Southern Asia, and in Tropical America, we mention only M. (Euprepes) vittata, on account of its partly semi-aquatic life, a very rare condition among Scincidae. This creature, about 7 inches long when full grown, frequents damp localities in Tunis and Algeria, where the French call it "Poisson de sable." It often sits on the floating leaves of Nymphaea alba, and dives into the water in order to escape. Its proper element is, however, the sand, and for the night it retires under stones. The general colour is olive brown with a lighter vertebral band and two narrow whitish lines on each side, sometimes edged with black. The under parts are yellowish or greenish white.

Chalcides s. Seps s. Gongylus, of the Mediterranean countries also occurs in South-Western Asia. The lower eyelid has a transparent disc. The body is much elongated, and is covered with smooth shiny scales. The limbs are very short, or reduced to mere vestiges.

Ch. ocellatus, of the Southern Mediterranean countries, occurring also in Malta and Sardinia, reaches about 10 inches in length. The snout is conical, the ear-opening a small slit or hole. The limbs have five fingers and toes. The under parts are uniform silvery white, but the colour of the upper parts is very variable, mostly olive brown with black spots and irregular cross-bars, or with dark and light spots; sometimes uniform bronzy brown with a light upper and a black lateral band. This Skink seems to have no fixed abode, but digs itself into the sand wherever it wants to hide. The skin is not shed in flakes, but, as in most Skinks, it peels off by a process of gradual desquamation. Fischer's specimens paired towards the end of December. The gestation lasted 56 days, when nine young were born, which measured about 75 mm. or 3 inches; when three weeks old they had increased to nearly double this length.

Ch. lineatus, of Spain and Portugal, and of the South of France, like Ch. tridactylus of Italy and North-West Africa, has only three fingers and toes. The fore-limbs are only about one quarter of an inch in length in large specimens of 10 inches total length; the hind-limbs are a little longer. The general colour is bronzy olive or brown above, in the former species with nine or eleven darker longitudinal streaks; uniform, and with an even number of streaks in the latter species. Ch. bedriagae, of Spain and Portugal, has mostly five fingers and toes, and the limbs are relatively longer in this smaller species; but it is a question if these and other species of this genus are not to a great extent simply individual variations, since the reduction of the limbs and toes seems to be a very recent feature. Ch. guentheri, of Palestine, otherwise in every respect like Ch. tridactylus, but reaching a length of more than 14 inches, has the limbs reduced to tiny conical stumps without a trace of separate digits.

I have caught Seps accidentally under stones or pieces of bark in sandy districts. On the western coast of Galicia and Portugal, close to the sea, they frequent the gorse-bushes, on which they can be seen basking, provided they are approached stealthily. They disappear on the slightest alarm, almost swimming, as it were, with great agility through the prickly cover, and then hiding and wriggling through the loose sand between the roots.

The following five "families" are composed of degraded forms of various descent. Most of them lead a burrowing, subterranean life, in adaptation to which the body has become snake-shaped or worm-like. The fore-limbs are entirely absent, except in Chirotes; the hind-limbs are absent, or reduced to small flaps; the girdles are reduced correspondingly. The skull is devoid of postorbital, postfronto-squamosal, supratemporal, and jugal arches. The quadrate bone is mostly immovable. The eyes and ears are concealed, except in the Pygopodidae.

Fam. 14. Anelytropidae.–An artificial assembly of a few degraded Scincoids. The worm-shaped, limbless body is devoid of osteoderms. The tongue is short, slightly nicked anteriorly, and covered with imbricating papillae. Columellae cranii are present. Anelytropsis papillosus in Mexico. Typhlosaurus and Feylinia in South and West Africa.

Fam. 15. Dibamidae, consisting of the genus Dibamus, with D. novae-guineae, in New Guinea, the Moluccas, Celebes, and the Nicobar Islands. The tongue is arrow-shaped, undivided in front, covered with curved papillae. Columellae cranii are absent. The vermiform body is covered with cycloid imbricating scales without osteoderms. The limbs and even their arches are absent, but in the males the hind-limbs are represented by a pair of flaps. Total length of the animal about 6 inches.

Fam. 16. Aniellidae.–The genus Aniella comprises a few small worm- or snake-shaped species in California, which seem to be degraded forms of Anguidae. The eyes and ears are concealed, limbs are entirely absent, the body and tail are covered with soft, imbricating, more or less hexagonal scales. The tongue is villose, smooth, and bifid anteriorly. The teeth are relatively large, few in numbers, recurved, with short swollen bases. The skull, by reduction, approaches the Ophidian type; there is no columella cranii, the postorbital arch is ligamentous, the premaxillary is single, the nasals and frontals remain separate, the pre- and post-orbitals are in contact with each other, excluding the frontal from the orbit.

A. pulchra.–Silvery, the scales edged with brown; back and tail with a narrow, brown, median line. Total length, 7 to 8 inches.

Fam. 17. Amphisbaenidae.–Worm-shaped lizards with the soft skin forming numerous rings, each of which is divided into many little squares, the vestiges of scales which are otherwise restricted to the head. The eyes and ears are concealed. Limbs are absent except in Chirotes, which has short four-clawed fore-limbs. The pectoral arch, and still more so the pelvic arch, are reduced to minute vestiges. The tail is very short. The skull is small, compact, and strongly ossified, in adaptation to the burrowing life, and is devoid of postorbital and postfronto-squamosal arches and of columellae. The teeth are either acrodont or pleurodont. The tongue is slightly elongated, covered with scale-like papillae, and bifurcates into two long and narrow smooth points.

The Amphisbaenas lead an entirely subterranean, burrowing life, like earth-worms. They are frequently found in ants' nests or in manure-heaps. Their progression is very worm-like, their annulated soft skin enabling them to make almost peristaltic motions and to move backwards as well as forwards. They crawl in a straight line, with slight vertical waves, not, like other limbless lizards or snakes, by lateral undulations. The food consists of worms and small insects. About one dozen genera with more than sixty species are known, most of which inhabit the warmer parts of America, the West Indies, and Africa. Four inhabit Mediterranean countries.

If the tongue and the dentition be taken as indications of relationship, the Amphisbaenidae may perhaps be considered as degraded descendants of Iguanidae, a family which contains various limbless, burrowing, worm-shaped forms. But it is also possible that the Amphisbaenidae are not a natural group. This consideration applies with most force to the genera Amphisbaena and Anops, the various species of which occur in America and in Africa.

Chirotes canaliculatus, the only species of the genus, is the only Amphisbaenid which still possesses fore-limbs. These are short, stout, placed close behind the head, and are provided with four-clawed digits. This species occurs in Mexico and California, is brownish or flesh-coloured, and reaches a length of about 8 inches.

Amphisbaena, with nearly thirty species, in Tropical America and Africa. On account of the short rounded-off head and the almost equally blunt tail these creatures are called by the natives "cobras de dous cabezas," i.e. snakes with two heads, or they are known as "maes das formigas," i.e. mothers of ants, because of their predilection for taking up their quarters in the nests of ants or termites. The scientific name refers of course to their capability of moving forwards and backwards (ἀμφίς, at both ends, and βαίνω, walk).

A. fuliginosa, one of the commonest species in South America and in the West Indies, is chequered black and white. The skin of the body has about two hundred rings, the tail about thirty. Total length between one and two feet. A more or less distinct fold extends along each side of the body from the neck to the tail, at the level where the dorsal scales originally joined the ventral scales.

Blanus is the only genus of the Mediterranean province. B. cinereus, of Portugal, Spain south of the Cantabrian range, Morocco, and Algeria, reaches a length of 10 inches, but such large specimens are rather rare. The general colour of the living animal is pink with a brownish tinge and with minute grey specks. The lateral lines or folds are well marked, and a stronger transverse fold is placed behind the head. The body shows from one hundred and ten to one hundred and twenty-five rings, the tail from twenty to twenty-two; each body-ring contains about thirty little squares or remnants of scales. There are a few pre-anal pores.

I have sometimes found this species in Portugal whilst digging for earth-worms in manure-heaps and similar moist places, where they lead the same life as the worms except that they live upon them and upon insects. When kept dry they become very thin and shrunken, but when put back into moist soil they again become turgid and supple within a short time. Those which I have kept in glass jars filled with rich mould throve very well, living upon the tiny insects and worms which infest such compost soil; they dug long tortuous channels, in which they moved forwards and sometimes backwards, but they never came to the surface.

Fam. 18. Pygopodidae.–Pleurodont, snake-shaped lizards, without fore-limbs, but with the hind-limbs appearing as a pair of scaly flaps.

The shoulder-girdle is much reduced. The hind-limbs, although very small and hidden within the scaly, almost fin-like flaps, still possess five toes. The ischium appears externally as a small spur on either side of the anal cleft. The eyes are devoid of movable lids, remaining open and unprotected; the pupil is vertical. The ear is either concealed or exposed. The tongue is fleshy, slightly forked and extensible. The body is covered with roundish imbricating scales. The tail is very long and brittle. The few genera of this undoubtedly natural family of unknown relationship contain in all about ten species, restricted entirely to Australia, Tasmania, and perhaps New Guinea. Next to nothing is known about their habits, except that some of them eat other lizards.

Pygopus lepidopus is distributed over the whole of Australia. It reaches a total length of about 2 feet, 16 inches of which belong to the tail. General colour coppery grey above, sometimes with several longitudinal series of dark spots.

Lialis burtoni of nearly the same size and equally wide distribution has the hind-limbs reduced to extremely small, scarcely visible, narrow appendages.

Sub-Order 3. Chamaeleontes.–Acrodont Old-World Saurians with a laterally compressed body, prehensile tail, and well-developed limbs with the digits arranged in opposing, grasping, bundles of two and three respectively.

The Chameleons are an essentially African family. About half of the fifty species known inhabit Madagascar, the others the African continent. One, the common Chameleon, is North African, extending into Andalucia; two others occur in South Arabia and Socotra, and only one in Southern India and Ceylon.

This sub-order is well distinguished from all other Saurians by several, mostly unique, characters. The tongue is club-shaped and extremely projectile, to a length equal to that of the body. The head is usually described as forming a casque, with prominent crests and tubercles. There is no tympanum and no tympanic cavity. The parietal bones, united into one, extend backwards far beyond the occiput, and the tip of this projection is met by a much-elongated supratemporal bone, which, partly fused with the squamosal, helps to enclose a huge supratemporal fossa. The latter is widely open behind. The postfronto-squamosal arch and the postorbital arch are strong. The jugal is widely separated from the quadrate; the latter stands vertically and is not reached by the pterygoid. There is no columella cranii. The pre- and post-frontals often join to form a supra-orbital roof. The nasals are very small and are excluded from the nares, which are bordered entirely by the enlarged prefrontals and by the maxillaries. The premaxillaries are small and carry no teeth. The latter are acrodont, compressed and tricuspid, and are restricted to the maxillaries and mandibles.

The limbs are peculiar. Not only are they relatively long and very slender, but two digits are permanently opposed to the other three. On the hand the first three fingers form an inner bundle opposed to the outer, or fourth and fifth fingers. On the foot the inner bundle is formed by the first and second, the outer by the other toes. The shoulder-girdle is of the ordinary Saurian type, but there are no clavicles and no interclavicle. The costal sternum is well developed; the ribs posterior to those which meet the sternum are very thin and elongated: they meet and fuse with their fellows in the medio-ventral line. These hoops are not connected with their neighbours in front or behind. The tail is prehensile by being rolled downwards; it is not brittle and is incapable of being renewed. The skin is not covered with scales, but with granules. The eyes are very remarkable. The eyeballs themselves are large, but the eyelids are united into one fold with a small central opening. However, when the Chameleon is asleep the margins of this opening sometimes become more slit-like. The right and left eye can be, and are incessantly, moved separately from each other, and the creature squints terribly. Each eyeball, together with the pin-hole eyelid, is rolled up and down, backwards and forwards, independently of the other eye. This is a unique feature, but it also occurs in people who squint badly. The question "What, and how, do these creatures see?" is therefore quite idle, especially since in reptiles binocular vision does not exist at all and, consequently, cannot be disturbed by squinting.

The tongue has attained an extraordinary development. The tongue proper (Fig. 152) is club-shaped, and is covered with a sticky secretion. The base or root of the tongue is very narrow, composed of extremely elastic fibres, and is supported by a much-elongated copular piece of the hyoid. The elastic part of the tongue is, so to speak, telescoped over the style-shaped copula, and the whole apparatus is kept in a contracted state like a spring in a tube.