CLASS REPTILIA $30 



ventral scales transversely enlarged; eyes functional 



and free. 

 Subfamily i. PYTHONIN.E. PYTHONS. Examples: Lox- 



ocemus, Liasis, Python (Fig. 460). 

 Subfamily 2. BOIN^E. BOAS. Examples: Epicrates, 



Boa, Ungalia. 

 Family 4. COLUBRID^E. HARMLESS and POISONOUS 



SNAKES. SERPENTES with facial bones movable; both 



jaws toothed. 

 Series A. AGLYPHA. COLUBRID^E with solid teeth, not grooved 



or tubular. Non-venomous. 

 Subfamily i. COLUBRIN^E. - - TYPICAL HARMLESS 



SNAKES. Examples: Thamnophis (Fig. 461), Zame- 



nis, Elaphe. 

 Series B. OPISTHOGLYPHA. COLUBRIM with grooved fangs in 



the rear of the upper jaw. Venomous. 

 Subfamily 2. HOMALOPSIN^E. RIVER SNAKES. Ex- 

 amples: Hypsirhina, Homalopsis. 

 Subfamily 3. DIPSADOMORPHLN^E. Examples: Tantilla, 



Philodryas, Oxyrhopus. 

 Series C. PROTEROGLYPHA. COLUBRID.E with fangs in the 



front of the upper jaw. Venomous. 

 Subfamily 4. HYDRIN.E. SEA-SNAKES. Examples : 



Hydrophis, Distira, Platurus. 

 Subfamily 5. ELAPIN.E. COBRAS and CORAL-SNAKES. 



Examples: Naja (Fig. 462), Elaps, Denisonia. 

 Family 5. VIPERID.E. THICK-BODIED POISONOUS SNAKES. 



Poisonous SERPENTES with a pair of large perforated 



fangs. 

 Subfamily i. VIPERIN^E. TRUE VIPERS. Examples: 



Vipera, Atractaspis. 

 Subfamily 2. CROTALIN.E. PIT- VIPERS. Examples: 



Crotalus (Fig. 466), Agkistrodon (Figs. 463 and 464), 



Lachesis. 



