1a in Illustrated Key to the Snakes of the Philippines

1a. Nasal scales separated by internasal scales; width of ventral body scales> 1/3 body width... .............................................................. Laticauda (p. 27) 1b. Internasal scales absent, nasal scales in contact with each other medially; width of ventral body scales variable............................................................... 2 2a. Width of ventral body scales> 1/3 body width........................ Aipysurus (p. 20) 2b. Width of ventral body scales <1/4 body width and often narrower than adjacent lateral body scales...................................................................... 3 3a. Three supralabial scales, second very elongate (Fig. 16)............ Emydocephalus (p. 24) 3b. More than three supralabial scales................................. Hydrophis (p. 24) FIGURE 16. Lateral view of head of Emydocephalus annulatus (specimen number unknown; a redrafting by EH of original image in Rasmussen et al. 2011). Second supralabial scale (reddish brown). Fig. 16, modified original line drawing reproduced with permission of A. Rasmussen and Zootaxa and Magnolia Press.