SIBYNOPHIS 



79 



Key to the Philippine genera of the Natricinse.* 



a\ Subeaudals double; maxillary teeth equal, or last two or three enlarged. 

 6\ Eye small, pupil round; scales smooth, without apical pits; snout 



obtuse --. Sibynophis Fitzinger (p. 79). 



b'. Eye large, pupil round; scales nearly all keeled, usuallj' with apical 



pits; snout obtuse Natrix Laurenti (p. 82). 



b'. Eye moderate, pupil vertically elongate; snout pointed; scales smooth, 



no apical pits Oxyrhabdium Boulenger (p. 99). 



a'\ Subeaudals single; anterior maxillary teeth enlarged and separated 

 from those following by a short interspace; eye moderate, pupil 

 round; snout obtuse;' scales smooth, without apical pits. 



Cyclocorus Dumeril and Bibron (p. 105). 



Fig. 6. Typical Natricinas head; after Griffin; Dendrelaphis terrificus (Peters), from Griffin's 

 fi^re of D. cxruleatus ; ch, chin shield; /, frontal: d. inferior labial; in, internasal ; lb, 

 superior labial; lo, loreal ; m, mental, or symphysial ; n, nasal; par, parietal; pf, prefrontal; 

 po, preocular ; pto, postocular; r, roatra) ; :jo, supraofular ; ta, anterior temporal; tp, 

 posterior temporal ; v, ventral. 



Genus SIBYNOPHIS Fitzinger 



Sibynophis Fitzinger, Syst. Rept. (1843) 26; Ste.jn'Eger, Proc. U. 



S. Nat. Mus. 38 (1910) 102. 

 Berpetodryas, part., Schlegel, Phys. Serp. 2 (18.37) 173. 

 Enicognathus Dumeril and Bibron, Erp. Gen. 7 (1854) .328. 

 Ablabes, part., GtJNTHER, Cat. Col. Snakes Brit. Mus. (1858) 27; 



Rept. Brit. India (1864) 223. 

 Enicognathus, part., .Jan, Arch. Zool. Anat. Phys. 2 (1863) 266. 

 Henicognathus CoPE, -Journ. Acad. Nat. Sci. Philadelphia 8 (1876) 



1.38; part., Bocourt, Miss. Sc. Mex., Rept. (1886) 625. 

 Polyodontophi.'; Eoulenger, Fauna Brit. India, Rept. (1890) 301; 



Cat. Snakes Brit. Mus. 1 (1893) 181; Griffin, Philip, Journ. Sci. 



§ D 6 (1911) 256. 



*The characters given here may not apply to extra-Philippine species 

 of the genera. 



