Recognition of Poisonous Snakes 



8. A. Tail with an enlarged and ornamented 



scute or with several spiny scales near 

 tip (SE Asia only) ; Indian rough- 

 scaled snakes "___ ITROPELTIDAE 



B. Xo such specialized tail, a single spine or 



none on tip 9 



9. A. Eye inider a distinct round scale; most of 



head covered with small granular 



scales 16 



B. Eye under irregularly-shaped head plate; 



head covered with enlarged scutes 10 



10. A. Scute containing nostril forms l)order of 



lip, 14 rows of scales around body; 



slender blindsnakes ..LEPTOTYPHLOPIDAE 



B. Scute containing nostril separated from 

 lip by surrounding scales: more than 

 14 scale rows: typical lilindsnakes TYPHLOPIDAE 



11. A. Ventral scutes extend full width of belly 15 



B. Ventral scutes narrow, not extending 



width of belly 12 



12. A. Ventrals scarcely twice size of dorsals, or 



less 13 



B. Ventrals distinctly enlarged, more than 3 

 times width of dorsals; boas and 

 pythons BOIDAE 



13. A. Head mainly t'ovcrcd witii small scales 16 



B. Head covered witii large scutes, though 



not in "typical" pattern (see fig. 6) 14 



14. A. A large median shield behind frontal: 15 



scale rows (SE Asia oniv); sunbeam 



snake '. XENOPELTIDAE 



B. No large median scute behind frontal: 17 

 scale rows or more (SE Asia and north- 

 ern South America). Pipe snakes ANILIDAE 



15. A. A spur-like hook on either side of vent 



(often hidden in small depressions) 12 



B. No indication of spurs 16 



IC. A. One or two large fangs near front of 



upper jaw on each side 17 



B. No sign of fangs at front of upper jaw. 

 Typical harmless snakes; about 2,000 

 species, only 2 in C. and S. Africa 

 are dangerous COLUBRIDAE 



17. A. Ijong fangs on short maxillary bone which 

 can rotate to ei'cct them; no other teeth 

 on maxillary 18 



31 



