_Habits._--Very much the same as in the preceding species, although slightly less thoroughly aquatic, large individuals being sometimes met with at some distance from water. Ponds and marshes are the favourite abode of the Viperine Snake, huge numbers being often found on the borders, diving into the water when disturbed. Frogs and toads, tadpoles, newts, fishes, and large earthworms, are its principal food when adult, the young feeding chiefly on batrachian larvæ, young fishes, and earthworms. A case is known of this snake having eaten a water-shrew (_Crossopus fodiens_). When a fish has been caught, it is usually eaten on land; in captivity dead fish are rather readily accepted, provided they be quite fresh. Some specimens bite when handled; others are as gentle as the Grass-snake. For hibernation, hollow trees, fissures in rocks, holes in the ground or in railway embankments, are selected, and numerous individuals sometimes congregate in the same retreat. In the mild winters of the South of Europe they remain quiet, without being torpid, and resume activity very early in the spring. In the Alemtejo, according to Gadow, when during the rainless and hot summer the small rivers have nearly dried up, these snakes collect in great quantities in the remaining stagnant and muddy pools, and, as the stock of suitable fish gets exhausted, are often reduced to a deplorably emaciated condition. By the month of August they have become so thoroughly aquatic that they cannot be kept alive in dry surroundings for twenty-four hours, apparently dying from some kind of cutaneous suffocation. The same observer once caught a Viperine Snake in a ditch whilst it was swallowing an eel of nearly its own length. Some specimens show so great a superficial resemblance to the Common Adder, _Vipera berus_, which, however, being a more northern reptile, very seldom occurs in the same localities--that this snake well deserves its name _Viperinus_. A celebrated herpetologist, Constant Duméril, was once himself deceived by this resemblance and bitten by a _Vipera berus_ which he had picked up in the Forest of Senart, near Paris, believing it to be a _Tropidonotus viperinus_; whilst, conversely, a specimen of the harmless snake was killed in mistake for a Viper by no less an expert than Dr. Viaud-Grandmarais. _Breeding._--This snake pairs in March and April, and sometimes again in the autumn; but the eggs are only laid at one season, in June or July, and hatch in August, September, or October. The eggs, numbering four to twenty, are deposited in holes not far from water, often in abandoned galleries of voles or moles. The young at birth measure 4 to 6-1/2 inches, and soon resort to the water, where, unlike those of the Grass-snake, they are frequently met with. GENUS ZAMENIS, WAGLER