DIVISION OPISTHOGLYPHA. 117 



Genus Leptodira. — Maxillary teeth 15 to 18, gradually and feebly 

 increasing in length, followed after an interspace by a pair of 

 enlarged grooved teeth situated just behind the vertical of 

 the posterior border of the eye ; mandibular teeth, anterior 

 slightly enlarged. Head distinct from neck ; eye large with 

 vertically elliptic pupil ; posterior nasal concave. Body cylin- 

 drical or moderately compressed ; scales smooth or faintly keeled, 

 with apical pits in 17 to 25 rows ; ventrals rounded ; sub-caudals 

 in two rows. 



Genus Cham^etortus.— Maxillary teeth 12, gradually and feebly increas- 

 ing in length, followed after a short interspace, by a large grooved 

 fang situated below the posterior border of the eye ; mandibular 

 teeth sub-equal. Head distinct from neck ; eye large with 

 vertically elliptic pupil ; posterior nasal concave ; loreal entering 

 the eye. Body compressed ; scales smooth with apical pits, 

 in 17 rows ; ventrals obtusely angulate laterally. Tail long ; 

 sub-caudals in two rows. 



Genus Amplorhinus. — Maxillary teeth 12 or 13, gradually increasing 

 in size, followed by an enlarged, grooved tooth ; mandibular 

 teeth sub-equal. Head distinct from neck ; eye moderate with 

 round pupil ; nasal semi-divided. Body cylindrical ; scales 

 smooth or feebly keeled, with apical pits, in 17 rows ; ventrals 

 rounded. Tail moderate ; sub-caudals in two rows. 



Genus Trimerorhinus. — Maxillary teeth 10 to 12, sub-equal, followed 

 after an interspace by a pair of enlarged, grooved fangs, situated 

 below the posterior border of the eye ; anterior mandibular teeth 

 strongly enlarged. Head distinct from neck; eye moderate, with 

 round pupil ; nostril crescentric, between two nasals and the 

 internasal. Body cylindrical ; scales smooth, with apical pits, in 

 17 rows; ventrals rounded. Tail moderate; sub-caudals in two 

 rows. 



Genus Rhamphiophis. — Maxillary short, with 6 to 9 teeth gradually 

 increasing in length and followed, after an interspace, by a 

 pair of very large grooved fangs situated below the eye ; anterior 

 mandibular teeth longest. Head distinct from neck, with 

 projecting snout; rostral large, hollowed out beneath; eye 

 moderate with round pupil ; nostril crescentric in a divided 

 or a semi-divided nasal. Body cylindrical ; scales smooth, 

 with apical pits, in 17 or 19 rows. Ventrals rounded. Sub- 

 caudals in two rows. 



Genus Psammophis. — Maxillary teeth 10 to 13, one or two in the middle 

 much enlarged, fang-like, preceded and followed by an inter- 

 space, the last two, large and grooved and situated below the 

 posterior of the eye ; anterior mandibular teeth very strongly 

 enlarged. Head distinct from neck, with angular canthus 

 rostralis ; eye moderate or large, with round pupil ; frontal 

 narrow. Body cylindrical ; scales smooth, more or less oblique, 

 with apical pits, in 11 to 19 rows ; ventrals rounded. Tail 

 long ; sub-caudals in two rows. 



Genus Dispholidus. — Maxillary short, widening behind, where it arti- 

 culates with the forked ectopterygoid ; teeth small, 7 or 8, 

 followed by three large grooved fangs situated below the eye ; 

 mandibular teeth sub-equal. Head distinct from neck, with 

 distinct canthus rostalis. Eye very large with round pupil ; 

 nasal entire. Body slightly compressed ; scales very narrow, 

 oblique, more or less strongly keeled, with apical pits, in 19 



