Glass Snake , (ophisaurus ventral is, Daud.), a North American reptile, improperly called a snake, belonging to the order saurophidia of Gray, and to the chalcidian or cyclosaurian family of saurians of Dumeril and Bibron. The head is lizard-like, sub-oval, with rounded snout, covered above with numerous polygonal plates, large anteriorly, the frontal the largest; the tongue arrow-shaped, triangularly grooved in front, free in its anterior extremity, on which the papillae are granular; the nostrils are near the snout, lateral, opening upward; the eyes are small, protected by two movable unequal lids; there are several rows of short conical teeth, about 30 in number, on the roof of the mouth, chiefly on the pterygoid bones; the intermaxillary teeth are conical, the maxillary simple and nearly cylindrical, about 40 in all above and 36 below; the external ear is a small oval opening just behind the angle of the mouth. There is no distinct neck; the body is elongated and snake-like, covered with small, smooth, slightly imbricated scales, disposed in circles around the body, about 120 in number; there is no vestige of anterior or posterior limbs externally, and only their rudiments internally; there is a deep groove separating the sides of the body from the abdomen, most visible during respiration, and which doubtless affords the free movements of the ends of the ribs necessary for progression.

The tail forms at least two thirds of the total length, round, and tapering gradually to the tip, covered with about 140 rings of scales. Though the shape of this reptile is snake-like, the movable lids, external auditory openings, less movable vertebra), less extensile tongue, rudimentary sternum, and above all the consolidation of the bones of the skull and jaws, sufficiently show its saurian affinities. The length varies from 2 1/4 to 3 1/2 ft. The head above is mottled with black and green, with a yellowish tinge on the jaws; the body and tail above are marked with longitudinal and transverse lines of black, green, and yellow, each scale marked with these three colors; the under surface is yellowish, brightest on the abdomen; some slight varieties of color are described. It is found on the Atlantic coast from southern Virginia to Florida, and as far west as the Mississippi, Missouri, and Ohio rivers; it has been seen west of the Alleghanies as for north as Michigan. From the smallness of its gape it cannot destroy and swallow large prey, like the serpents; it cannot climb nor swim, but passes its life on the surface of dry places or in natural cavities in the ground, living principally on mollusks, insects, annelids, and other small animals, and perhaps also partly on vegetable food like the sweet potato.

It can move with considerable speed, and is taken uninjured with difficulty on account of the ease with which the joints of the tail are separated; the name of glass snake was given on account of this extreme fragility. The breaking of the tail into small pieces in this and in some seincoid reptiles seems to be the result of a reflex action in the spinal cord, as an irritation of this nervous centre will cause a separation even after the tail is divided from the body. Dr. Burnett ("Proceedings of the Boston Society of Natural History," vol. iv., p. 223) ascertained that the caudal muscles in this reptile do not pass from one vertebra to another, but that a portion are inserted into the skin, while others terminate midway between one vertebra and the next, dovetailed as it were between the fibres sent from that vertebra, and attached to them only by the myolemma; so that there is no rupture of muscular fibres, but only a separation of one layer of muscles from the adjoining one, when the tail of the animal is broken; the detached portion is said to be reproduced in a year.

The glass snake in its anatomical peculiarities resembles the chalcidian amphisbaena and the scincoid blind worm (unguis fragills).

Glass Snake (Ophisanrus ventralis).

Glass Snake (Ophisanrus ventralis).