Hypnale

Maduwage, Kalana, Silva, Anjana, Manamendra-Arachchi, Kelum & Pethiyagoda, Rohan, 2009, A taxonomic revision of the South Asian hump-nosed pit vipers (Squamata: Viperidae: Hypnale), Zootaxa 2232, pp. 1-28 : 24

Key to the Species of Hypnale

1a. No small scales between postfoveal and 3rd supralabial; no diamond-shaped scale between postocular, 1st lower temporal, and 4th and 5th supralabials, which are in contact ( Figs. 1 a, 6a, 8a); hemipenial lobe not spinous ( Figs. 1 d, 6d) ................................................................................................................................................................................. 2

1b. 1–3 small scales between postfoveal and 3rd supralabial ( Fig. 4 a); a diamond-shaped scale between postocular, 1st lower temporal, and 4th and 5th supralabials ( Fig. 4 a); hemipenial spines present ( Fig. 4 d) ................ Hypnale nepa

2a. Snout tip not elevated; 3–5 small scales behind rostral ( Figs. 1 a, 8a); lacunal scale present ( Figs. 1 a, 8a)................. 3

2b. Snout tip distinctly elevated ( Fig. 6 a); 10–19 small scales comprise wart-like protuberance behind rostral ( Fig. 6 a); lacunal scale absent ( Fig. 6 a) .................................................................................................................. Hypnale zara

3a. Two rows of distinct suboval or subtriangular blotches meet on dorsal midline, bilaterally symmetrical (especially on tail), sometimes displaced longitudinally on body ( Fig. 3 b); 1st infralabials contact one another at a median suture ( Fig. 1 c); 7–8 supralabials ......................................................................................................... Hypnale hypnale

3b. A distinct purple-brown, about 3 scales wide paravertebral stripe extends from neck to level of vent ( Fig. 9 a); 1st infralabials contact each other on mid line, forming a single scale ( Fig. 8 c); 8 or 9 supralabials .... Hypnale sp. ‘amal’

Figures

FIGURE 1. Hypnale hypnale, WHT 5852, male, 311.0 mm SVL: a, b, c, lateral, dorsal and ventral aspects, respectively, of head; d, e, everted left hemipenis, showing (f) enlarged view of a hemipenial lobe; g, dorsal view of paravertebral scale; h, medial view of right palatine of WHT 5857, male, 343.0 mm SVL.

FIGURE 3. Hypnale hypnale: a, dosal aspect of neotype, BNHS 2531 - 759, female, 350.0 mm SVL; b, dorso-lateral aspect of a specimen from Galle, Sri Lanka (not preserved); c, reproduction of drawing of H. hypnale in Russell (1801).

FIGURE 4. Hypnale nepa, WHT 6515, neotype, male, 367.0 mm SVL: a, b, c, lateral, dorsal and ventral aspects, respectively, of head; d, e, everted left hemipenis, showing (f) enlarged view of a hemipenial lobe; g, dorsal view of paravertebral scale; h, medial view of right palatine of WHT 6082, male, 292.0 mm SVL; and i, distribution in Sri Lanka: H. nepa (solid circles), H. walli type locality (open circle).

FIGURE 6. Hypnale zara: WHT 2198, male, 338.0 mm SVL: a, b, c, lateral, dorsal and ventral aspects, respectively, of head; d, e, everted left hemipenis, showing (f) enlarged view of a hemipenial lobe of WHT 5848, 288.0 mm SVL; g, dorsal view of paravertebral scale of WHT 2198; h, medial view of right palatine of WHT 6089, male, 297.0 mm SVL; and i, distribution in Sri Lanka. Scale bars = 1 mm.

FIGURE 8. Hypnale sp. ‘ amal’, WHT 7140, male, 325.0 mm SVL: a, b, c, lateral, dorsal and ventral aspects respectively of head; d, dorsal view of paravertebral scale; e, medial view of right palatine; and f, distribution in Sri Lanka.

FIGURE 9. Hypnale sp. ‘ amal’: a, WHT 7140, male, 325.0 mm SVL; b, collection locality: a home garden at Wataraka, Galle, Sri Lanka.