40 

 Group III. — Dryadina. Bush Colubers. 



Their compressed body, numerous ventrals ^ocys. 

 (200 or more), and general green coloration 

 show that they are transitional to the families 

 of true tree-snakes. 



Group IV. — Natricina. Amphibious Colubers. 

 These lead off to the river-snakes : their Tropidonotus. 



' Atretium. 



nostrils are often superior : their scales are Xenochrophis. 



^ Frymnonnodoy%, 



always more or less keeled ; the ventrals con- Cadmus. 

 siderably less than 200 ; long teeth at the back 

 of the maxillary. 



Fam. XIV. Dendrophid^. Tree SnaJces. 

 Body slender, snout rather long but rounded Gonyosoma. 



J ' & _ Phyllophis. 



fairly ; eye moderate or large with round Dendrophis. 



GhrysopeUa. 



pupil. Ventrals broad with two lateral keels. 



Fam. XV. DRYiOPHiDiE. Long-nosed Tree SnaJces. 

 Body excessively slender ; head narrow with Ti-opidococcyx-. 



•^ " \ Tragops. 



the rostral shield developed into a snout often Fasserita. 

 of some length. Eye moderate with horizon- 

 tal pupil. 



Fam. XVI. Dipsadid^e. Broad-headed Tree Snakes. 



Body slender, much compressed. Head very ^ipsas. 

 distinct from the neck, short and broad. Eye 

 moderate, with vertical pupil. 



Fam. XVII. Psammophid.e. Desert Snakes. 



A class of snakes resemblinor the tree-snakes Psammophis. 



° Fsammodynaittt, 



in their form, but of terrestial habits. Body 

 slender, head very distinct from the neck, head- 

 shields normal. 



