(1) dorsal scale rows 27–29 – 25–27 – 23–25, distinctly keeled, small, cycloid, progressively larger on the top of the body than on the sides; (2) scales of the first DSR distinctly enlarged, also two per ventral, first smallest, last largest; (3) ventrals 177–189, large, laterally rounded; (4) subcaudals 55–56, undivided; (5) 1st–4th or 1st–5th supralabials, mental, and 2nd–4th infralabials with raised and everted edges; (6) suture between the internasals 0.7 times as long as suture between the prefrontals; (7) 1 / 1 (upper) preocular, 1 / 1 supraocular, 2 / 2 postoculars, and 1 / 1 subocular; (8) 1 / 1 loreal, large; (9) nuchal scales 3, one in central and one enlarged on each side; (10) dorsum dark purplish-grey, slightly paler on the sides; and (11) neck with a pale creamish-grey collar, more or less pronounced with age, reaching downwards the pale grey colour of the venter.