Natricinae

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 : 19

Natricinae

Key to Philippine genera.

1a. Fewer than 10 supralabial scales................................................ 2

1b. More than 10 supralabial scales................................. Opisthotropis (p. 31)

2a. One of the following combinations of characters true: (1) dorsal body scales in 15–17 longitudinal rows at midbody and background color of ventral body scales black; (2) dorsal body scales in 19 longitudinal rows at midbody and background color of ventral body scales pale (but not pinkish) in life................................................ Rhabdophis (p. 33)

2b. One of the following combinations of characters true: (1) dorsal body scales in 17 longitudinal rows at midbody and background color of ventral body scales pale; (2) dorsal body scales in 19 longitudinal rows at midbody and background color of ventral body scales pinkish in life.............................................................. Tropidonophis (p. 35)