Colubrinae

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 : 18-19

Colubrinae

Key to Philippine genera.

1a. Dorsal body scales in 19–27 longitudinal rows at midbody........................... 2

1b. Dorsal body scales in 14–18 longitudinal rows at midbody........................... 4

2a. Pupil strongly vertically elliptical ( Fig. 28A )............................ Boiga (p. 20)

2b. Pupil circular or slightly vertically elliptical ( Fig. 28B ).............................. 3

3a. Dorsal body scales in 23–27 longitudinal rows at midbody; body emerald green in life, blue after preservation in alcohol...................................... Gonyosoma (p. 24)

3b. Dorsal body scales in 21 longitudinal rows at midbody; body not emerald green in life, not blue after preservation in alcohol.................................... Coelognathus (p. 22)

4a. Dorsal body scales in 15–17 longitudinal rows that do not reduce posteriorly; subcaudal scales 27–54 pairs..................................................... Oligodon (p. 30)

4b. Dorsal body scales may or may not reduce posteriorly; if dorsal body scales do not reduce posteriorly, then subcaudal scales in> 100 pairs.................................... 5

5a. Lateral edge of supraocular scale robust, protruding over eye rather than curving around eye ( Fig. 29A ); dorsal body scales usually in 14, 16, or 18 longitudinal rows at midbody......................................................................... Ptyas (p. 33)

5b. Lateral edge of supraocular scale not robust, and curves with contour of eye ( Fig. 29B ); dorsal body scales usually in 15 or 17 longitudinal rows at midbody......................... 6

6a. Loreal scale absent; dorsal body scales in 15 longitudinal rows at midbody.. Liopeltis (p. 27)

6b. Loreal scale present; dorsal body scales in 15–17 longitudinal scale rows at midbody..... 7

7a. One or more of the following combinations of characters true: (1) dorsal body scales in 17 longitudinal rows at midbody, and 184–216 smooth ventral body scales; (2) dorsal body scales in 15 longitudinal rows at midbody and ventral body scales keeled......... Lycodon (p. 28)

7b. Dorsal body scales in 17 longitudinal rows at midbody, 220–232 smooth ventral body scales............................................................. Stegonotus (p. 34)

Figures

FIGURE 28. Lateral view of head of (A) Boiga angulata (KU 343853), (B) Coelognathus erythrurus manillensis (KU 335195). Note vertically elliptical (A) versus rounded pupil (B).

FIGURE 29. Lateral view of head of (A) Ptyas luzonensis (KU 306605), (B) Stegonotus muelleri (KU 344097). Supraocular scale (reddish brown) of Ptyas robust, protruding over eye.