120 INTRODUCTION 



American) do not lend themselves any better than 

 the ordinary divisions of physical geography to the 

 study of the distribution of Snakes. Contrary to 

 what we find in dealing with the Tortoises, Australia 

 does not show any special affinity to South America, 

 and, as in the case of the Lizards, it must be 

 regarded as an impoverished extension of the Indo- 

 Malay fauna; as with the Lizards, also, Europe and 

 Africa hang together, whilst Madagascar stands apart, 

 distinguished by many negative features and some 

 points of agreement with South America (Boidse). 

 There is a greater difference between the Snakes of 

 Europe and those of Eastern Asia than there is 

 between the latter and those of North America, 

 whilst in Lizards a primary distinction must be made 

 between the Old World and the New. Southern 

 Asia east of Persia (the Oriental Region) is the great 

 Ophidian centre, all the groups mentioned above, with 

 the exception of the Dasypeltinse, having representa- 

 tives within its limits, and a large and very distinct 

 family, the Uropeltidse, being confined to it. The 

 Pythoninse occur along with the Boinae, the Viperinae 

 with the Crotalinae, and the Elapinae are represented 

 by varied forms, as they are also in Africa and still 

 more in Australia, where they form the overwhelm- 

 ing majority, and in some parts, as well as in 

 Tasmania, the exclusive Ophidian population. The 

 coasts of India and Malaya are also the home of the 

 great majority of the Hydrophiinse. Large genera 



