Central Asian specimens are of a pale yellowish sand-colour, with a brown, dark-edged dorsal zigzag band or series of spots and two series of small spots on the sides. Belly whitish, dotted or spotted with black, or uniform blackish.

Size.—23 inches is the length of the largest specimen examined.

Distribution.—In Europe V. renardi, which has long been confounded with V. berus, is abundant in the district of Uralsk, in the steppe around Sarepta, in Crimea, and it is also found in Cis-Caucasia and in Bessarabia. Its range extends far into Central Asia, being known from the Khirghiz steppes, the Emba steppes, the steppes near the Alatau, on the borders of the Urdshar, and in the Semipolatinsk district. Around Sarepta it is common in the bare steppe, and only exceptionally occurs in localities overgrown with willows and small shrubs.

Habits.—Nothing has been published concerning the habits of this snake, except that it is more sensitive to cold than V. berus and does not appear before the middle of April, retiring to its winter-quarters in the beginning of October. The food consists of small mammals and lizards.

Reproduction.—Pairs in May, and brings forth five to seven young in August, these young at birth measuring about 51⁄2 inches.

23. Vipera berus, Linnæus
The Northern Viper, or Adder

Form.—Short and stout. Snout flat above, rarely slightly concave, the upper contour broadly rounded or truncate in front, the canthus well marked, sometimes slightly raised, the loreal region nearly vertical. Eye as a rule smaller in females than in males, as large or nearly as large as the nasal shield; its vertical diameter equals or a little exceeds its distance from the mouth. Length of tail five and a half to nine times in total length in males, eight to ten and three-quarter times in females.