294 HISTORY OF THE EUROPEAN FAUNA. 



has died out at its former headquarters in Southern 

 Asia and all along the line of migration, except at 

 the extreme limits of the range in both directions 

 east and west. 



As we go down in the scale of life among the lower 

 vertebrates and invertebrates we meet with a greater 

 number of prominent members of the Lusitanian 

 migration. The Bullfinch, Dipper, and Chough, 

 which might be thought to be of Lusitanian origin, 

 are, as I have shown in the last chapter, Asiatic. 



The European snakes seem to be all of eastern 

 origin, unless TropidonotiLS viperinus might be claimed 

 as a Lusitanian form. Of very great interest from 

 a zoogeographical point of view is our only European 

 member of the South American and African family 

 Amphisb&nida. This species Blanus cinereus is 

 of the size and shape of an ordinary earth-worm, 

 from which, however, it may be distinguished by its 

 snake-like wriggling motions. It lives under stones 

 in Spain and Portugal, North-west Africa, and 

 Greece. It has, therefore, a somewhat similar dis- 

 tribution to that of many of the animals and 

 plants referred to in the last chapter. But here 

 we have an animal which has evidently utilised the 

 old Mediterranean route described on p. 271, from 

 west to east. Two other species of Blanus inhabit 

 Asia Minor and Syria, but most of its nearest relations 

 either live in South America or tropical Africa. In 

 migrating to North and West Africa, its ancestors 

 probably made use of the land-bridge which spanned 



