The Colubrida3 family conaprises the greater part of the non-venomous snakes, namely, all those which do not present any striking character either in their general habit, in the shields of the head, in the dentition, or in any other part of their organization. They have numerous teeth in the jaws and on the palate, but no fangs in front or in the middle of the maxillary. Numerous species of Coluber, sp., Linn., are found in North America, Europe, and Asia • those in British .India belong to the northern pa'rts of this region scarcely ex tending southwards into the tropical' region.
• Ptyas =coatis, Cope, is the Indian rat snake. It is light brownish-olive, scales with darker margins, is one of the most common species on the continent and in Ceylon, and appears to occur e,verywhere ; it is scarce in the Archipelago, as its occurrence has been recorded in Java only ; on the other hand, it is not rare in Chusan and Formosa. In the Himalaya it ascends to only 5240 feet above the level of the sea. It is a powerful snake, attaining to a length of 7 feet, the tail being one-third, or rather more. Its food consists of mammals, birds, and frogs ; it fre quently enters the dwellings of man, in search of mice, rats, and young fowls. It is of fierce habits, always ready to bite, and old specimens brought to Europe never become tame. Cantor says that it utters, when irritated, a peculiar diminuendo sound, not unlike that produced by a gently struck tuning-fork.
Tropidonotus junceus, Cantor, inhabits Penang, and, like most of the Asiatic species of this genus, is of fierce habits.
Tropidonottui quincunciatus and T. umbratus. The former is the most widely-spread species of the East Indies, ra‘nging from Mesopotamia into the southern parts of China, and inhabiting most of the islands of the western half of the Archi pelage. It abounds near rivers and pools, feed ing on frogs and fishes ; it attains to a length of 3 feet, and is of fierce habits. The ground colour of the upper parts is generally greyish or brownish olive.
Tropidonotus macrophthalmus. This species may be at once distinguished by its large eye, and by its dilatable neck, the scales of which show an axra.iigement very similar to that of a cobra, for which it is frequently taken. Found in Khassya and Sikkim,—in the latter country at an elevation of 4000 feet. Attains to 39 inches, the tail
measuring 7 inches.
Tropidonotus stolatus, Boie, Isis. This is per haps the most common species of snake on the East Indian continent, ranging from Ceylon through the Peninsula, along the southern slope of the Himalayas to Southern China (Formosa) ; it is scarcer in the Malayan Peninsula and the northern parts of Siam, and appears to be entirely absent in the Archipelago. It is of very gentle habits, feeding on small frogs ; it attains to a length of 2 feet, but generally smaller.
Another family are Fresh-water Snakes, the Homalopsida3. All the Indian fresh-water snakes of this family have a grooved fang at the hinder extremity of the maxillary bone. They are aquatic, and are only occasionally found on the beach ; several of them even enter the sea, and in several points of their organization approach the truly marine snakes, with which they have been asso ciated in Gray's system. They may easily be recognised by the position of the nostrils on the top of the snout, which enables them to breathe by raising but a very small part of their head out of the water ; it is the same arrangement as that in the crocodiles, sea-snakes, and other aquatic animals. Many have a distinctly prehensile tail, by means of which they hold on to projecting objects, Their food consists entirely of fish, and, in a few species, of crusta,cea also. All of them appear to be viviparous, and the act of parturition is performed in the water. They do not grow to any considerable size, are of a gentle disposition, and their bite would be by no means dangerous.. They will not feed in captivity, and therefore die after a short time.
Psamnaodynastes pulverulentus, Gunth., ia one of the family Psaininophida3 or Desert Snakes.,.
Ma one has a very repulsive aspect ; its (lark, undefined colours, short and thick head, and swollen lips, caused by large hidden fangs, give it the appeantnce of a venomous snake.
The tenth family aro Tree Snakes, or Dendro phiclx. They are diurnal species, living in trees, and feeding chiefly on tree lizards ; they are found in all the tropical regions.
The Whip Snakes, or Dryophithe, aro the eleventh finally. Asiatic species have a long fang like tooth in the middle of the maxillary, and all provided with 11 posterior grooved tooth.