Dendrelaphis, Boulenger, 1890

Kraus, Fred, 2025, New species of snakes of the genus Dendrelaphis (Squamata: Colubridae) from the Milne Bay Islands, Papua New Guinea, Zootaxa 5618 (4), pp. 451-480 : 478

Given that van Rooijen et al. (2015) recognized six Dendrelaphis species in Melanesia

and I recognize ten, it seems useful to provide an updated key to the species in that region. I exclude the two species ( D. keiensis , D. striolatus ) clearly extralimital to Melanesia, for which the key provided by van Rooijen et al. (2015) is sufficient. Van Rooijen et al. (2015) also considered D. punctulatus to be restricted to Australia and, hence, extralimital to Melanesia, and they placed all New Guinean snakes formerly assigned to D. punctulatus in D. macrops . However, snakes I have collected from eastern Papua New Guinea do not accord with D. macrops and presumably represent true D. punctulatus . This issue requires further investigation, but in the meantime I conservatively include D. punctulatus in the key below.

1 Adults black/dark gray above and below, chin and throat white, juveniles gray or brown............................. 2

- Adults other than black with white chin and throat........................................................... 4

2 Pale vertebral stripe present on anterior body......................................................... D. roseni

- Pale vertebral stripe absent on anterior body................................................................ 3

3 Labials and chin matte white heavily stained or dusted with black, no sharp demarcation between color fields on supralabials; hemipenis without large spines basally, calyculate distally, with large transverse ridge that encircles entire organ..... D. atra

- Labials and chin glossy white with few or no glossy black markings, black on dorsal portions of supralabials sharply demarcated from white on ventral portions; hemipenis with large spines basally and many small spines distally, transverse ridge limited to a semicircle on left of sulcus spermaticus........................................................ D. anthracina

4 Head speckled with dark markings; EY much smaller than EN......................................... D. lorentzii

- Head unspeckled with dark markings; EY subequal to or larger than EN.......................................... 5

5 Tail and top of head black; body paler with wide (ca. 1 scale width) and widely separated, oblique black bars... D. lineolatus

- Tail and top of head same color as body; no wide, oblique black bars on body..................................... 6

6 Black postocular stripe absent........................................................................... 7

- Black postocular stripe present........................................................................... 8

7 EY> EN;> 140 subcaudals..................................................................... D. macrops

- EY ≤ EN; <140 subcaudals.................................................................. D. punctulatus

8 Venter with large black spots interspersed amongst small dark speckles................................ D. gastrostictus

- Venter uniform or with few dark markings but no larger black spots or dense speckling.............................. 9

9 Dorsum with pale vertebral stripe anteriorly....................................................... D. papuensis

- Vertebral scales same color as surrounding scales........................................................... 10

10 Each dorsal scale margined with black, forming narrow oblique lines along each scale row; hemipenis with large spines basally, many small spines distally................................................................... D. melanarkys

- Dorsal scales not margined with black to form narrow oblique lines along each scale row; hemipenis without large spines basally, calyculate distally.................................................................... D. calligastra