Maxillary teeth subequal. Head not or but slightly distinct from neck; eye moderate or rather small, with round pupil. Nasal single; no subocular shields. Body moderately elongate; scales smooth, with apical pits. Tail moderate.

This genus, with certain modifications in the above definition, is made to embrace about twenty-five species from South-Western Asia and Sind and North and Central America. One of the species inhabiting Asia extends into a very small part of Europe.

Form.—Moderately slender. Head small, quite flat above; snout obtuse, feebly prominent. Length of tail four to five times in the total length.

Head-Shields.—Rostral a little broader than deep, visible from above. Suture between the internasals as long as or a little shorter than that between the prefrontals. Frontal once and a half to once and two-thirds as long as broad, as long as or longer than its distance from the end of the snout, shorter than the parietals, as broad as or a little broader than the supraocular, widely separated from the preocular. Nostril in the middle or upper part of the nasal. Loreal square or longer than deep. One (rarely two) pre- and two (rarely one) postoculars. Temporals 1 + 2; parietal sometimes nearly touching the fifth upper labial. Upper labials seven, third and fourth entering the eye. Four (rarely five) lower labials in contact with the anterior chin-shield; posterior chin-shields smaller than the anterior, and separated from each other by one or two rows of scales.

Coloration.—Not unlike that of a young Zamenis gemonensis. Greyish-olive above, uniform or each scale lighter in the centre. The greater part of the upper surface of the head behind the snout, together with the nape, black in the young, with a yellow cross-bar or a pair of yellow spots between the eyes, the bar sometimes confluent with the yellow postoculars, and a horseshoe-shaped band of the same colour on the temples and across the occiput (Plate X.); the black of the nape again edged with yellow behind. More or less distinct traces of these markings are preserved in adult specimens. Upper lip yellowish, with black spots or bars on the sutures between the shields. Lower parts uniform white or yellowish.

In the var. semimaculata, Boettger, from Chios, small dark spots are scattered over the upper parts of the anterior half of the body.

Size.—This snake rarely reaches a length of 19 inches. It is the smallest Colubrid of Europe.

Distribution.—The Caucasus up to about 5,000 feet, Asia Minor, Chios, Cyprus, Syria, Mesopotamia, and North-Western Persia. The northern slope of the Caucasus appears to be the only part of Europe included in its habitat. The British Museum possesses two specimens labelled as from Constantinople, but the presence of this species in European Turkey requires confirmation.

A closely allied species, which has been confounded with C. modesta, C. collaris (Ménétriès), and which also inhabits the Caucasus without having been recorded from the northern slope, is distinguished by having the scales in fifteen rows (very rarely seventeen), and the posterior chin-shields in contact with each other.

Habits.—Nothing is known as regards this species, but the North American members of the genus Contia are chiefly insectivorous and oviparous.

Maxillary teeth small and subequal, followed after a short interspace by one or two very large grooved fangs situated below the posterior border of the eye; anterior mandibular teeth strongly enlarged. Head not very distinct from neck, with angular canthus rostralis and projecting supraocular; eye large, with round pupil; nostril a crescentic slit in a single or divided nasal. Body elongate; scales smooth, more or less distinctly grooved longitudinally in the adult, with apical pits. Tail moderately long.

The range of this genus, which comprises only two species, extends over Southern Europe, South-Western Asia, and North Africa.

Form.—Slender; head elongate, narrow, concave above on the snout and between the eyes; snout projecting, rounded, with raised canthus and concave loreal region. Tail about one-fifth to one-fourth of the total length.

Head-Shields.—Rostral nearly as deep as broad, just visible from above. Internasals much shorter than the prefrontals. Frontal very narrow, twice to twice and a half as long as broad, its width in the middle not more than half that of the supraocular, widening in front and extending beyond the supraoculars to join the preoculars, longer than its distance from the end of snout, as long as or a little longer than the parietals. Two loreals. One preocular, the upper portion of which is much enlarged, and encroaches upon the area occupied in other snakes by the prefrontal and the supraocular; two (rarely three) postoculars. Temporals 2 + 3 or 4. Upper labials eight (rarely nine), fourth and fifth (or fifth and sixth) entering the eye. Four or five lower labials in contact with the anterior chin-shields, which are as long as or shorter than the posterior.

Scales with single apical pits, in seventeen or nineteen rows, longitudinally grooved in the adult, less distinctly in the young. Ventral shields 160 to 189; anal divided; subcaudals 68 to 102.

Coloration.—The young is elegantly marked with dark brown and yellowish-white on a pale brown ground. On the head, the principal dark markings usually are an oblique band on the posterior half of the supraocular shield, and another, or a large spot, on the parietal, sometimes produced backwards, and forming with its fellow a Λ-shaped band, separated from a large occipital blotch by a yellowish space; anterior half of the frontal shield and shields on the snout edged with dark brown; a dark streak, sometimes broken up into small spots, on the temporal region; yellow spots on the pre- and post-oculars; lips brown, with large, yellow, black-edged spots, or yellow with brown spots; chin with three brown longitudinal streaks. Back with a vertebral series of large roundish dark spots or narrow cross-bars; small spots on the sides, these sometimes forming longitudinal series or accompanied by yellowish streaks or dots; these markings often confluent into three longitudinal streaks on the tail. Belly pale brownish, greyish, or reddish, with numerous pale spots, sometimes with a dark brown line on each side. The adult is greyish, reddish-brown, or olive above. Some specimens preserve more or less the markings of the young, and the dark dorsal markings (Plate XI.) may be edged with yellowish and ocellar in appearance (var. insignitus, Geoffroy); the belly is yellowish, with small dark spots which usually form longitudinal series, and may be confluent into streaks. A variety common in Dalmatia (neumayeri, Fitzinger) is brown or olive above, without spots, sides with a bluish-grey lateral band, the scales on which are edged with black, the belly uniform yellow. Other specimens are brown or reddish, with light edges to the scales on the sides, or with yellowish lateral lines, or dark olive or dark brown above and black on the sides, each scale with a yellowish central spot; in the last-mentioned the second third of the back may be almost entirely black, and the belly dark olive-grey in the middle and yellowish on the sides. Iris brown, with a golden or coppery circle round the pupil.

Size.—This handsome snake grows to a length of 61⁄2 feet. Specimens 5 to 6 feet long are not uncommon.

Distribution.—Mediterranean coast of France and Western Liguria, Spain and Portugal, Sicily, Lampedusa, eastern coast of the Adriatic, Greece and eastern islands of the Mediterranean, Mediterranean coast of Asia and Sinaitic Peninsula, eastwards to the Caucasus and Persia, North Africa from Egypt to Rio de Oro. It is not known to occur above 2,300 feet altitude in Europe.

Habits.—A lively, swift snake, living on land and on low bushes, often found near human habitations. Some specimens are very vicious, whilst others show a gentle disposition after a short period of captivity. A specimen nearly 6 feet long, which I kept for some time, never attempted to bite when handled, and some have become so tame as to take food from the hand. The sense of sight appears to be better developed than in any other European snake. The food consists chiefly of mammals, even large rats and young rabbits, birds such as chickens, partridges, and quails, lizards, and other snakes, which, if of considerable size, are not swallowed until paralyzed or killed by the effect of the poison. In Eastern Europe, Vipera ammodytes is said to be the principal enemy of Cœlopeltis, and the two snakes are consequently seldom found together in the same locality.

Many experiments have been made on the action of the poison of this Opisthoglyph. Peracca and Deregibus, as well as, later, Phisalix, found a striking similarity with the symptoms of Cobra poison in their experiments on small animals, the suspension of the respiration occurring in a few minutes, the blood being otherwise unaffected. It has been stated by some authors that Cœlopeltis poison has little or no action on man, but a French zoologist, E. Taton-Baulmont, having been bitten in the index-finger by a four-foot-long specimen at Algiers, the swelling extended within thirty hours up to the shoulder, and was accompanied by fever and nervous troubles. As a rule, however, the bite of this snake has no poisonous effect on man, from the fact that the fangs conveying the venom are situated so far back in the mouth as not to come into action.

Reproduction.—According to Werner, the eggs, four to twelve in number, are laid in July, and measure 2 inches in length and 1⁄2 inch in width.

Maxillary teeth few and very unequal in size, fourth and fifth or fifth and sixth enlarged and followed by an interspace, the two last teeth fang-like and grooved, situated just behind the eye; sixth mandibular tooth fang-like, and separated from the remainder by an interspace. Head slightly distinct from neck; eye rather small, the pupil vertically elliptic or subelliptic when contracted. Body moderately elongate; scales smooth, with apical pits. Tail moderate or rather short.

A single species.

Form.—Very similar to the Smooth Snakes, with which it has been confounded, but snout broader and very strongly depressed. Tail five and a half to six and a half times in the total length.

Head-Shields.—Rostral at least twice as broad as deep, not or but scarcely visible from above. Internasals as long as or a little shorter than the prefrontals. Frontal not much broader than the supraocular in the adult, once and a half to twice as long as broad, as long as or longer than its distance from the end of the snout, shorter than the parietals. Nasal usually semidivided. Loreal once and a half to twice as long as deep. One preocular, extending to the upper surface of the head, but not reaching the frontal; two (rarely one or three) postoculars. Temporals 1 + 2. Upper labials eight, fourth and fifth entering the eye, sixth usually in contact with the parietal. Four or five lower labials in contact with the anterior chin-shields, which are as long as or a little shorter than the posterior.

Scales with mostly single apical pits, the pits sometimes paired on the sides of the body, in twenty-one or twenty-three rows (nineteen to twenty-five in North African specimens). Ventral shields 153 to 192; anal divided; subcaudals 40 to 54.

Coloration.—Pale brown or greyish above, with small dark brown or blackish spots or with more or less distinct darker and lighter longitudinal streaks. Upper surface of head with dark brown vermiculations; a dark brown or black, often light-edged occipito-nuchal band, extending downwards to the gular region and produced forwards into a point to between the parietal shields; a dark brown or black streak on each side of the head from the end of the snout, through the eye, to the last lower labial shield, traversing the four last upper labials, which are yellowish above and below the streak (Plate XI.). Lower parts yellow or coral red, with black spots, which may form a tessellated pattern, two longitudinal series, or be so crowded as to fuse into a band along the middle of the belly and tail.

The above description is taken from Spanish specimens (Badajos, Algeciras, Andalucia), but the variations are very great when we take North Africa into consideration. The nuchal band may be narrow or broken up into spots, the median of which sometimes forms a longitudinal streak, or so much enlarged as to fuse with the dark markings on the upper surface of the head; in some specimens (from Morocco and Algeria) the upper surface of the head and the nape may be entirely ink black, or the whole head black above and beneath with the exception of a whitish streak bordering the upper lip. The dark streak from the eye to the angle of the mouth may be absent, or reduced to a short oblique streak below the eye. Irrespective of the variations in the markings of the upper parts, the lower parts may be more or less spotted with black, or immaculate.

Some specimens of this small snake bear a general resemblance to Coronella girondica, with which Macroprotodon has sometimes been confounded. But a careful examination of its whole structure shows it to be more affine to Cœlopeltis and Tarbophis, the other European representatives of the Opisthoglyphous Colubrids.

Size.—The largest European specimen examined measures 171⁄2 inches. Specimens up to 22 inches long occur in Algeria and Tunisia.

Distribution.—In Europe this snake is only known from Spain (Estremadura, New Castille, Andalucia), Portugal (Alemtejo), the Balearic Islands (Majorca and Minorca), and the island of Lampedusa. In North Africa it is generally distributed from the north coast of Egypt to the Rio de Oro; in Algeria it penetrates into the northern parts of the Sahara. The specimen figured on Plate XI. is from Algeciras.

Habits.—Appear to be similar to those of Coronella girondica. Crepuscular in its habits, it is usually found under stones or in burrows in the ground. Unless pursued, when it darts off with great rapidity, its movements are slow. It is very ready to bite, but no experiments have been made on the effects of its poison. The food consists chiefly of small lizards.

Reproduction.—All that is known on this head is that, according to Doumergue, eggs are laid in July in Algeria.

Maxillary teeth few, anterior longest, gradually decreasing in size posteriorly, and followed, after an interspace, by a pair of enlarged, grooved fangs, situated below the posterior border of the eye; anterior mandibular teeth strongly enlarged. Head distinct from neck; eye moderate or rather small, with vertically elliptic pupil. Body moderately elongate; scales smooth, oblique, with apical pits. Tail moderate or rather short.

The eight species of this genus inhabit South-Eastern Europe, South-Western Asia, and Africa. Two are dealt with here.

Form.—Moderately slender. Head much depressed. Tail five and a half to seven times in the total length.

Head-Shields.—Rostral broader than deep, just visible from above. Internasals shorter than the prefrontals. Frontal much broader than the supraocular, once and one-fourth to once and a half as long as broad, as long as its distance from the end of the snout, shorter than the parietals. Nasal divided or semidivided. Loreal twice and a half to thrice as long as deep, entering the eye below the preocular, which is in contact with the frontal. Two (rarely three) postoculars. Temporals small, scale-like, 2 or 3 + 3 or 4. Upper labials eight (rarely seven or nine), third, fourth, and fifth (rarely fourth and fifth, or fourth, fifth, and sixth) entering the eye. Three or four lower labials in contact with the anterior chin-shields; posterior chin-shields very small and widely separated from each other by scales.

Scales with single or paired apical pits, in nineteen or twenty-one rows, usually nineteen in European specimens. Ventral shields 186 to 222; anal divided; subcaudals 48 to 73.

Coloration.—Greyish above, with 40 to 57 brown or black spots or bars on the body; a lateral series of smaller spots or vertical bars, alternating with the dorsals; the first spot, on the nape, elongate, usually with one or three linear processes in front, extending on the head (Plate XI.); usually a dark streak on each side of the head, from the eye to the angle of the mouth. Lower parts whitish, speckled, spotted, or marbled with grey or brown. Iris brown, with a golden circle round the pupil.

Size.—This species grows to a length of 2 feet 10 inches.

Distribution.—From Istria and Dalmatia to Greece, the Archipelago, Constantinople, Asia Minor, Cyprus, and Northern Syria; 2,600 feet appears to be its altitudinal limit.

Habits.—Although to a certain extent crepuscular or nocturnal, the Cat-snake is often seen hunting in the daytime, its food consisting almost exclusively of lizards, rarely of small mammals. Its movements are rather slow. The names Katzenschlange and Ailurophis, translated Cat-snake, probably originated from the way in which this snake stalks its prey, and suddenly pounces upon it. According to Eiffe, the poison causes the death of a Lacerta vivipara in one minute, and P. de Grijs observed the larger Lacerta agilis to die in two or three minutes. As a rule even fresh-caught specimens allow themselves to be handled without attempting to bite; some specimens, on the other hand, are very savage. Stony localities, old walls, and ruins, are the favourite abodes of this snake, which does well in captivity.

Reproduction.—Seven or eight eggs are laid in July; they measure about 11⁄4 inches in length and 1⁄2 inch in width.

Very closely allied to the preceding, and differing from it only in the following points: Parietals shorter, slightly longer than the frontal, and anal entire. Loreal twice to twice and a half as long as deep. Fourth and fifth, or third, fourth, and fifth, labials entering the eye. Scales in nineteen or twenty-one rows. Ventrals 203 to 235; subcaudals 54 to 70.

Grey above, with 35 to 40 blackish spots on the body, the anterior largest and darkest; a lateral series of smaller spots or vertical bars. Lower parts blackish, with small whitish spots and dots. Reaches a length of 31⁄2 feet.

This species inhabits the Caucasus, and, being on record from the northern slope (Kuban River), has to be included in the European fauna. It occurs also in Mesopotamia, a specimen from Bagdad being preserved in the British Museum. The young specimen figured on Plate XI. is stated to be from Constantinople.

Nothing is known of its habits, which are probably the same as those of Tarbophis fallax.