DENTITION 59 



a. Mandibular teeth 17 to 30 ; maxillary teeth 

 15 to 22. 



Posterior maxillary teeth longest ; mandibular teeth 

 subequal, more than 20 Tropidonotus. 



Posterior maxillary teeth longest ; mandibular teeth 

 not more than 20, posterior smallest Zamenis. 



Maxillary teeth subequal ; mandibular teeth 20 to 25, 

 posterior smallest Coluber. 



b. Mandibular teeth 14 or 15, subequal ; maxil- 

 lary teeth 12 to 15. 



Maxillary teeth increasing in size Coronella. 



Maxillary teeth subequal Contia. 



B. One or two enlarged grooved fangs behind the 

 series of solid maxillary teeth. 

 14 to 17 subequal solid maxillary teeth, forming a 

 continuous series ; 21 to 23 mandibular teeth, 



anterior strongly enlarged Ccelopeltis. 



g to 11 solid maxillary teeth, fourth and fifth or fifth 

 and sixth enlarged, followed by an interspace ; 

 sixth mandibular tooth fang-like, followed by an 



interspace Macroprotodon. 



9 or 10 solid maxillary teeth, forming a continuous 

 series, decreasing in length posteriorly ; anterior 



mandibular teeth strongly enlarged Tarbophis. 



C. Maxillary with only two large canaliculated 

 fangs side by side, one of which may be miss- 

 ing ; anterior mandibular teeth longest 



Viper a, Ancistrodon. 



