β. Snout usually more or less turned up at the end or produced into a scaly dermal appendage; supraocular not extending posteriorly beyond the vertical of the posterior border of the eye; frontal and parietals often absent or very small; 2 or 3 series of scales between the eye and the upper labials; 9 to 13 upper labials; scales in 21 or 23 rows, rarely 19 or 25.
Snout simply turned up, the raised portion bearing 2 or 3 scales; rostral not more than once and a half as deep as broad; ventrals: ♂ 134-158, ♀ 141-169
Vipera aspis.
Snout simply turned up or produced into a small appendage, the raised portion with 5 or 6 (rarely 3) scales; rostral 11⁄2 to 2 times as deep as broad; ventrals: ♂ 125-146, ♀ 135-147
Vipera latastii.
Snout produced into an appendage covered with 10 to 20 scales; rostral not reaching the summit of the rostral appendage; ventrals: ♂ 133-161, ♀ 135-163
Vipera ammodytes.
γ. Snout not turned up at the end; supraocular narrow or broken up into several small shields; upper surface of head with small, usually keeled scales; two or three series of scales between the eye and the upper labials; scales in 23 to 27 rows, usually 25; ventrals: ♂ 151-177, ♀ 153-180
Vipera lebetina.
b. A pit between the nostril and the eye; upper surface of head with 9 large shields; nasal in contact with the rostral; third upper labial entering the eye; scales in 23 rows; ventrals 149-174; subcaudals 31-44