40 



Group III.— Deyadina. Bush Colubers. 



Their compressed body, numerous ventrals f/^^//„^,^,_ 

 (200 or more), and general green coloration 

 show that they are transitional to the families 

 of true tree-snakes. 



Group IV. — Natbicina. Amphibious Colubers. 



• Tropidonoi 

 Atretium. 



These lead off to the river-snakes ; their ^^^jf"""'"'' 



nostrils are often superior; their scales sxe^'^^'^^opM'- 

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

 siderably less than 200 ; long teeth at the back 

 of the maxillary. 



Fam. XIV. DENDEOPHiDiE. Tree Snakes. 



Body slender, snout rather long but rounded Oonuosoma. 

 fairly ; eye moderate or large with round Dendrophis. 

 pupil. Ventrals broad with two lateral keels. 



Farth. XV. DRYlOPHiD.a:. Long-nosed Tree Snakes. 

 Body excessively slender ; head naiTow with Tropidococcyx, 



Tragopa. 



the rostral shield developed into a snout often Faiaenta. 

 of some length. Eye moderate with horizon- 

 tal pupil. 



Fam. XVI. DiPSADiDiE. Broad-headed Tree Snakes. 



Body slender, much compressed. Head very Jiip>a'- 

 distinct from the neck, short and broad. Eye 

 moderate, with vertical pupil. 



Fam. XVII. PsAMMOPHiDiE. Desert Snakes. 



A class of snakes resembling the tree-snakes ^sammdphis. 



° FsammodynaiiM. 



in their form, but of terrestial habits. Body 



slender, head very distinct from the neck, head- 

 shields normal. 



