308 HISTORY OF THE EUROPEAN FAUNA. 



SUMMARY OF CHAPTER VII. 



The term " Lusitanian " is in this chapter employed in the 

 wide sense, as indicating the South-west of Europe and North- 

 western Africa. From this centre, and probably also from a 

 now sunken land which lay to the west of it, issued a fauna and 

 flora of which we have abundant evidence in our own islands, 

 especially in Ireland. Edward Forbes held that the Lusitanian 

 element of the British flora was of miocene age, and that it 

 survived the Glacial period in this country. 



At the time when the Straits of Gibraltar did not exist, and 

 when there was free land communication between Asia Minor, 

 Greece, and Tunis, many Oriental species migrated westward 

 by this ancient Mediterranean route as far as Spain. They 

 would then have invaded the more central parts of Europe from 

 the south-west, without however being of Lusitanian origin. Of 

 the true Lusitanian mammals a typical example is the Rabbit. 

 Then we have a few birds and several interesting reptiles and 

 amphibians. The genus to which the Brimstone Butterfly 

 belongs is also of south-western origin. A number of Mollusca 

 are mentioned which from their range likewise indicate a Lusi- 

 tanian origin. Most of our British Slugs and many of our 

 larger Snails belong to this group. 



All these are merely a small remnant of what we received 

 from South-western Europe during the Miocene and Pliocene 

 Epochs. But they spread into many parts of Europe, and a 

 few even crossed into Asia. The antiquity of the Lusitanian 

 element in our fauna is especially indicated by the frequent 

 recurrence of "discontinuous distribution" among the species 

 belonging to that section. 



