406 MANUAL OF ZOOLOGY. 



also, is usually covered with small scales, rarely interspersed 

 with larger plates or "scuta" (fig. 158). The Colubrina 

 include for the most part harmless snakes, but together with 

 these are some of the most deadly of all the venomous snakes. 

 In accordance with this they are often divided into the three 

 sections of the Innocua, Suspecta, and Venenosa. In the first 

 of these sections (Innocua), the superior maxillae are pro- 

 vided with solid teeth only, and there are no fangs. In this 

 section are the common Ringed Snake of our own country and 

 the Boas and Pythons of warm climates. The common Ringed 

 Snake ( Coluber natrix) of Britain is a perfectly harmless animal 

 which is commonly found in damp situations, and which lives 

 mainly upon frogs. Closely allied to this is the Black Snake 

 (Coluber constrictor) of North America, also perfectly harmless. 

 The Boidce or Boas and Pythons are the largest of all living 

 snakes, attaining a length of certainly over twenty feet. Their 

 bite is perfectly harmless, but they are nevertheless highly 

 dangerous and destructive animals, owing to their great size 

 and enormous muscular power. They seize their prey and coil 

 themselves round it in numerous folds, by tightening which 

 they gradually reduce their victim to the condition of a shape- 

 less bolus, fit to be swallowed. In this way a good-sized 

 Python or Boa will certainly dispose of an animal as large as 

 a sheep or goat, and it is asserted that even human beings may 

 be devoured in this way by large individuals of the family. 

 The Boas and Pythons occur in both the Old and New World, 

 the Pythons, however, all belonging to the Old World ; and 

 they are amongst the most formidable of all living Ophidians. 



In the section Suspecta, in which there are canaliculated 

 fangs placed far back on the superior maxillae, with smaller 

 solid teeth in front of them, are certain unimportant snakes, 

 partly aquatic and partly terrestrial in their habits, and all be- 

 longing to the Old World. 



In the group Venenosa, in which there are canaliculated 

 fangs placed in front of the superior maxillae with smaller solid 

 teeth behind them, are some of the most deadly of all living 

 serpents. One of the best known of these is the Hooded 

 Snake, or Cobra di Capello (Naja tripudians), which is com- 

 monly found in Hindostan, and is the snake usually carried 

 about by the Indian snake-charmers. Also in this section are 

 the venomous Water-snakes (Hydrophidce), which have a com- 

 pressed tail, and are adapted for an aquatic life. They mostly 

 frequent the mouths of rivers in droves, and they swim with 

 great grace and rapidity. 



A very good general character by which the Colubrine snakes 



