_Head-Shields._--Rostral as deep as broad or slightly broader than deep, just visible from above. A pair of internasals and a pair of larger prefrontals. Frontal as broad as the supraocular, as long as or a little longer than its distance from the end of the snout, as long as or a little shorter than the rather short parietals. Supraocular extending beyond the vertical of the posterior border of the eye. Loreal pit between three shields, separated from the labials. Nostril between two nasals, the posterior of which is separated from the upper preocular by a loreal. Two preoculars, one or two postoculars, and a subocular. Three large lower temporals, anterior largest. Upper labials seven or eight, third and fourth largest, third entering the eye. A pair of small chin-shields. _Scales_ sharply keeled, with two apical pits, in twenty-three rows. Ventral shields 149 to 174; anal entire; subcaudals 31 to 44 pairs. _Coloration._--Pale yellowish-grey, greyish-brown, or reddish, sometimes greenish in young specimens, with transverse series of darker spots or with more or less regular dark bars with serrated edges across the back (Plate XIV.); these bars may be narrower than the interspaces between them, or so large as to cause the back to appear brown with light cross-bars; the bars sometimes broken up on the vertebral line, and the two halves alternating. The sides usually paler and bearing two alternating longitudinal series of small spots, the lower of which are usually darker, and sometimes extend on the outer ends of the ventral shields. Head pale above, with a dark spot on the middle of the snout, a cross-bar or a pair of spots between the eyes, a spot or short band on each side of the parietal region, and a horseshoe-shaped band on the occiput, the branches of which are more or less produced on the nape; all these markings sometimes confluent. A broad, dark, light-edged band on the temple. Lips whitish, speckled with brown. Lower parts whitish, more or less profusely speckled with grey or brown. The horny shield terminating the tail usually dark brown or black at the end. _Size._--This species rarely reaches a length of 29 inches. The largest specimen in the British Museum measures only 19 inches. _Distribution._--From the north and east coasts of the Caspian Sea, across Central Asia to the Upper Yenissei, as far north as 51°. In Europe it is only known from two arid tracts between the Volga and the Ural, near the Caspian Sea, viz., the Saltan-Murat desert and the Induski hills. _Habits._--Nothing has been published on the habits of this snake, but they are probably similar to those of its near and more eastern relative, _A. blomhoffi_, Schlegel, which inhabits China and Japan. _A. blomhoffi_ is said to be more or less nocturnal, although showing a predilection for localities well exposed to the sun. It is ovoviviparous. The symptoms of its bite, which is rarely fatal to man, are the same as in the Vipers.