Horseshoe pit viper

small internasals, 2nd supralabial in contact with loreal pit, 21 rows of smooth or weakly-keeled dorsal scales at midbody, and a single row of scales between labials and suboculars. The common name of the species is based on the presence of a pale buff horseshoe-shaped (i.e., inverted 'U') mark on the nape. The snake is pale brownish or buff coloured with darker blotches of grey and some white streaks.