A. acutus.—The snout of this snake is prolonged into an appendage directed forwards. The head-shields are finely granulate. Body scales arranged in 21 rows; 162-166 ventrals; 58-60 subcaudals.
Coloration brown on the back, with blackish-brown X-shaped spots; head dark brown, yellow on the cheeks, with a black band running from the eye to the angle of the jaw; belly yellowish, spotted with brown, with a series of large black transverse blotches.
Total length, 1,500 millimetres; tail 200.
Habitat: Upper Yang-tse, China.
A. halys.—Snout prolonged into an upturned appendage, blunt at the tip; 7-8 supralabial scales, the third of which forms part of the margin of the eye; body scales in 23 rows; 149-174 ventrals; 31-44 subcaudals.
Coloration yellowish, grey, red, or pale brown above, with darker spots or cross-bars. A black spot on the snout; two black spots on the vertex; a dark, light-edged band on the temple; belly whitish, more or less speckled with grey or brown.
Total length, 490 millimetres; tail 65.
Habitat: From the borders of the Caspian Sea and the Ural River to the Upper Yenisei; Turkestan.
A. intermedius.—Resembles the foregoing very closely, but the snout is not turned up at the end.
Total length, 750 millimetres; tail 85.