300 HISTORY OF THE EUROPEAN FAUNA. 



tion is therefore of particular interest. It is difficult to 

 conceive that Platyarthrus, from its peculiar mode of 

 life, could have crossed any formidable barrier, such 



FIG. 19. Map of the British Islands on which the geographical distri- 

 bution of Geomalaats maculosus is indicated in black. 



as even a narrow straits of sea. Its occurrence in 

 Spain and North Africa indicates, therefore, that the 

 Straits of Gibraltar did not exist at the time when 



