An imperfect albino, which has been met with several times in Dalmatia, has been described as var. flavescens, Werner. Yellowish-white or brownish-yellow above, with small blackish spots; belly whitish in the middle, with a series of black spots, bright yellow on the sides; eye and tongue red.
Size.—This snake occasionally reaches a length of 4 feet, but specimens over 3 feet are rare. The largest specimen in the British Museum measures 3 feet 10 inches.
Distribution.—The Tessellated Snake has a wide range in Europe and Asia. It is found south of the Alps, from Liguria to Naples, and eastwards, extending northwards over the greater part of Austria-Hungary, and even as far as Saxony, and again reappears to the west in various localities of the Middle Rhine district (from Bingen to Coblenz and Kreuznach, from Nassau to Lahnstein) and of the Moselle. From Southern Russia it extends into Siberia as far as the Altai, the extreme west of China, and the extreme north-west of India; it is also found in Asia Minor, Transcaucasia, Persia, Mesopotamia, Syria, and the neighbouring parts of Egypt. Italy and the Rhine constitute the western limit of its range in Europe. It does not ascend to any considerable altitude in the mountains of Europe, but it is on record from 6,000 feet elevation in Chitral.
Habits.—This is a far more aquatic species than the preceding, being seldom found in summer away from the water, in which it swims and dives to perfection; which does not prevent it from being equally agile on land. In accordance with these thoroughly aquatic habits, it feeds mostly on fish, although occasionally taking frogs and toads and their tadpoles. Small fish are swallowed in the water, but large ones are landed. This snake does not object to salt water, and it has been observed on the seashore near Odessa, chasing small fish, mostly gobies, in shallow water. Hibernation and pairing take place on land, and it is not until the latter function is accomplished that the snakes of this species resort to the water, which the females leave again for oviposition. Like the Grass-snake, the Tessellated Snake seldom bites.
Reproduction.—Pairing takes place in spring, when large numbers have been observed to congregate for the purpose. As in the Viperine Snake, a second pairing may occur in the autumn, Dr. Werner having found a pair in copula on September 14, at Trebinje, Herzegovina, the female laying her eggs in the following July, which with the beginning of August is the time for oviposition. The eggs measure a little over an inch in length and two-thirds of an inch in width, and number 5 to 25; they are deposited under stones, in the fissures of walls and rocks, or under the refuse of tanneries.
5. Tropidonotus viperinus, Latreille
The Viperine Water-Snake
Form.—Moderately slender; head shorter than in the preceding species; snout obtuse, not prominent; eyes and nostrils directed upwards and outwards, the former rather small, the latter somewhat valvular; tail four to six times in the total length.
Fig. 18 (after Sordelli)