SNAKES ■ 127 



{a) The Aglypha, harmless snakes, which have all the 

 teeth solid, not grooved. 



{b) The Opisthoglypha, which are more or less poisonous, 

 having the posterior maxillary teeth grooved. 



(c) The Proteroglypha, which are all highly poisonous, 

 having the anterior maxillary teeth grooved or canaliculated. 



The Aglypha are divided up into the following three 

 sub-families. 



1. The Jcrochordime. — Aquatic snakes, which are dis- 

 tinguished by their juxtaposed, or small wart-Hke tuber- 

 cular scales. 



2. The Colubrince. — The typical harmless snakes. 



3. The Rhachiodontince. — Egg-eating snakes with rudi- 

 mentary teeth. 



The members of the sub-family Acrochordincs live in 

 fresh or brackish water, some species occasionally swimming 

 out to sea. 



The scales of the body are juxtaposed, not overlapping, 

 as in the typical snakes, while the nostrils are situated on 

 the top of the head. 



Acrochordus javanicus, the Elephant Trunk Snake, as 

 this very ugly snake is called in the Malay Peninsula, on 

 account of the superficial resemblance of its thick grey 

 body to an elephant's proboscis, inhabits the ditches and 

 canals of Siam and the Malay Peninsula and Archipelago. 

 The head, which is not at all distinct from the neck, is 

 covered, like the whole body, with small, rough scales, 

 resembling the shagreen of sharks. The scales, which are 

 all alike, there being no enlarged ventral shields, number 

 up to 150 round the body. 



