Oligodon

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 : 30-31

Oligodon

Key to Philippine species.

1a. Dorsal body scales in 15 longitudinal rows at midbody.............................. 2

1b. Dorsal body scales in 17 longitudinal rows at midbody.............................. 3

2a. Light vertebral stripe present; no prominent dorsal body blotches; quadrangular black spots present on ventral body scales.................................... Oligodon modestus

2b. Light vertebral stripe absent; light dorsal body spots or blotches usually present; distinctive markings absent from ventral body scales.......................... Oligodon notospilus

3a. Number of supralabial scales usually six; number of anterior temporal scales two; no transverse markings on dorsal surface of body............................... Oligodon meyerinki

3b. Number of supralabial scales usually seven; number of anterior temporal scales one or two; transverse markings present on dorsal surface of body............................... 4

4a. Dorsal body blotches> 30, irregularly shaped, forming poorly defined dark crossbands; number of ventral body scales> 180; number of ventral body scales + subcaudal scales> 230 (females; unknown for males)..................................... Oligodon perkinsi

4b. Dorsal body blotches well-defined, numbering <30; number of ventral body scales <180; number of ventral body scales + subcaudal scales <220.............................. 5

5a. Dark dorsal body blotches extend laterally to ventral body scales; two preocular scales ( Fig. 41A ); number of ventral body scales + subcaudal scales 211–216....... Oligodon maculatus

5b. Dark dorsal body blotches saddle-shaped, not extending to ventral body scales; usually one preocular scale ( Fig. 41B ); number of ventral body scales + subcaudal scales 183–207................................................................... Oligodon ancorus

Figures

FIGURE 41. Lateral view of head of (A) Oligodon maculatus (KU 321699), (B) Oligodon ancorus (KU 346379). Preoc- ular scales (green).