_Size._--This Viper exceptionally attains a length of 3 feet. The largest male in the British Museum measures 2 feet 6 inches, the largest female 2 feet 4 inches. In _V. berus_ females grow to a larger size than males; in this species, as in _V. aspis_, the reverse appears to be the rule. _Hybrid._--A female specimen, presumed to be a hybrid between _V. berus_ and _V. ammodytes_, was obtained by Captain Veith in 1902 in Carinthia, in a locality where both these species occur together. The shape of the head is exactly that of a typical _V. aspis_, the snout distinctly turned up at the end, but without wart or scaly appendage, the raised portion being covered by the apex of the rostral shield and three apical shields. The rostral shield, which is a little deeper than broad (5 : 4), extends above the level of the slightly raised canthus rostralis, which bears two shields, the second in contact with the supraocular. The naso-rostral extends to the canthus rostralis, where it joins the first canthal and the lateral apical shield; one series of scales between the nasal shield and the preoculars. On the upper surface of the head the snout is covered with fifteen subimbricate smooth scales, in addition to the canthals and apicals. A frontal shield and a pair of parietals are well developed, although smaller than in an average _V. berus_; the parietals are in contact with the frontal, between which and the supraoculars two series of scales intervene. The supraocular, as in _V. berus_, extends backwards considerably beyond the vertical of the eye. Eleven scales round the eye; two series of scales between the eye and the labials. Temporal scales smooth. Upper labials nine, fourth and fifth below the eye. Scales in twenty-one rows, outer row smooth. Ventrals 159; subcaudals 31. Grey-brown above, with a reddish-brown or mahogany-coloured zigzag vertebral band and a lateral series of paler reddish-brown spots; temporal band ill-defined in front; no markings on the upper surface of the head; lips pinkish, with a few reddish-brown spots. Ventral shields pale brownish, finely speckled or powdered with blackish, and with small whitish spots on the free edge and reddish brown spots on the sides. Tail orange red below. Iris fire red. Total length 2 feet 2-1/3 inches; tail 2-2/3 inches. _Distribution._--The typical form is known from Northern Venetia, Austria-Hungary (Styria, Carinthia, Southern Tyrol, Carniola, Illyria, Istria, Croatia, Slavonia, and eastward through Southern Hungary to Transylvania), Dalmatia, Bosnia, Herzegovina, Montenegro, Albania, and Servia. In the Alps up to 1,300 feet, in the Balkan Peninsula up to 7,500 feet. The var. _montandoni_ inhabits Roumania and Bulgaria. The var. _meridionalis_ inhabits Greece, with the Archipelago, Asia Minor, and Syria.