26 



skin (in some species) is somewhat tightly welded 

 to the vertebrae. 



The Achrochordinae is a small sub-family of 

 snakes which connects the semi-aquatic forms 

 mentioned above with the Sea-snakes. 



These snakes are covered with small tubular 

 and strongly-keeled scales, and some of the genera 

 have no ventrals, but have slightly compressed 

 tails, and resemble the Hydrophiinae. 



The Dipsadinae belong to the back-fanged 

 class. The largest and most important genera are 

 arboreal (Dipsas, Dryophis, Chrysopelea), and have 

 compressed bodies. 



The Homalopsinae are the true fresh-water 

 snakes, with nostrils on the upper surface of the 

 snout, and rather compressed tails. They also 

 belong to the back-fanged group. 



The Elapinae are, apart from the Bungarums, 

 better represented in Australia than in the East. 

 They are poisonous front-fanged Colubers, and 

 include many of the most deadly snakes in 

 existence. 



They are regular in shape, except for the 

 genus Callophis, which is composed of small thin 

 snakes that in outward appearance resemble earth 

 snakes, are often known as Coral snakes, and are 

 most numerous in Australia. The Elapinae, by 

 the way, are all terrestrial. 



The Hydrophiinae are the sea-snakes proper, 

 front-fanged, and very deadly, with granule-like 

 scales, flat tails, and no ventrals. 



This concludes the family Colubridae. 



8. The A mblycephalidae are blunt-headed snakes 

 with compressed bodies. They can only expand 

 their jaws slightly, have no mental groove, and are 

 harmless. 



9, The Viperidae. This family is divided into 

 two sub-families (i) Viperinae, (2) Crotalinae. The 



