The _Typhlopidæ_, or Blind Snakes, comprise forms which are the most remote from the true Ophidian type. They live under ground, their rigid body and short curved tail being adapted for burrowing. After showers of rain they occasionally appear above ground, and then they are tolerably agile in their serpentine movements. The eye, which is scarcely visible in many species, can give to them only a general perception of light. They feed on worms and small insects, the tongue being forked, and, as in other Snakes, frequently exserted. They are oviparous. The smallest species of Snakes belong to this family, some of them being only half the size of a common earth-worm, to which they bear a superficial resemblance. Such, indeed, are the small vermiform Snakes already referred to, as being foolishly considered Venemous by most natives of India. Species of this family inhabit almost every country within and near the tropics. The _Tortricidæ_ are akin to the _Typhlopidæ_, and have rudiments of hind limbs hidden in a small groove on each side of the vent, also a longitudinal fold at the chin. The "Coral Snake" of Demarara (_Tortrix scytale_) appertains to this family; and the genus _Cylindrophis_, different species of which inhabit the great Asiatic archipelago, with the island of Ceylon. The family _Xenopeltidæ_ consists of a single species only, so far as hitherto known, the _Xenopeltis unicolor_, which is common in the Indo-Chinese and Malayan countries. It grows to three or four feet in length, and when alive is uniformly steel-blue, most beautifully iridescent, beneath white; but the blue fades to brown after long immersion in spirits. Young examples have a white collar. Mr. W. Theobald remarks of it that "this Snake is common in Lower Pegu and the Tenasserim provinces, and is very malignly beautiful, though of repulsive physiognomy. The skin is loose and thick, and its habits are nocturnal. The following illustrates its ferocious nature:--I once remarked a Colubrine Snake (_Ptyas mucosa_), some five feet in length, in the hedge of the Circuit-house of Bassein. On running downstairs, the Snake had vanished, but on searching for it I saw its tail sticking out of a hole beneath a wooden plant-case. Do what I might I could not drag it out, as it seemed held fast within. I therefore, with some trouble, overturned the plant-case, and then saw that the unlucky Colubrine Snake was firmly pinned by a large _Xenopeltis_, into whose hole it had unwittingly entered. The _Xenopeltis_ seemed about four feet in length; but, on perceiving itself uncovered, released its hold of the _Ptyas_ and made its escape." The _Xenopeltis_ preys chiefly on small mammalia, which it hunts for in their subterranean holes; and in some respects it approximates the _Pythonidæ_.