Illustrated Key to the Snakes of the Philippines Author Weinell, Jeffrey L. Department of Ecology and Evolutionary Biology and Biodiversity Institute, University of Kansas, Lawrence, Kansas 66045; jweine2@gmail.com Author Hooper, Errol Department of Ecology and Evolutionary Biology and Biodiversity Institute, University of Kansas, Lawrence, Kansas 66045; Author Leviton, Alan E. Herpetology Division, Institute of Biodiversity Science & Sustainability, California Academy of Sciences, 55 Music Concourse Drive, San Francisco, California 94118. * Corresponding author; Email: jweine 2 @ gmail. com Author Brown, Rafe M. Department of Ecology and Evolutionary Biology and Biodiversity Institute, University of Kansas, Lawrence, Kansas 66045; text Proceedings of the California Academy of Sciences 2019 2019-09-30 66 1 1 49 journal article 299708 10.5281/zenodo.11512680 ccd739a4-10c3-4700-b27e-459bd82f1676 0068-547X 11512680 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