Hologerrhum

Weinell, Jeffrey L., Hooper, Errol, Leviton, Alan E. & Brown, Rafe M., 2019, Illustrated Key to the Snakes of the Philippines, Proceedings of the California Academy of Sciences 66 (1), pp. 1-49 : 24

Hologerrhum

Key to Philippine species.

1a. Posterior border of parietal scales unnotched ( Fig. 34A ); dark midventral stripe present; dark midlabial stripe present....................................... Hologerrhum dermali

1b. Posterior border of parietal scales notched ( Fig. 34B ); dark midventral stripe absent; dark midlabial stripe absent........................................ Hologerrhum philippinum

Figures

FIGURE 34. Dorsal view of head of (A) Hologerrhum dermali (CMNH 5075), (B) Hologerrhum philippinum (KU 330056). Parietal scales (reddish brown); black arrows point to posterior margin of parietal scale, showing unnotched pari- etal pattern (A), or notched parietal pattern (B).