2/0 HISTORY OF THE EUROPEAN FAUNA. 



than four species of Bacillus are known from Europe, 

 according to our great authority Mr. Brunner von 

 Wattenwyl all from the south ; and some of these 

 also range into North Africa. There are thirty-two 

 other species distributed over Southern Asia, Africa, 

 Australia, New Zealand, and the Sandwich Islands. 



Volumes, indeed, might be filled with lists of 

 species and genera of terrestrial invertebrates of 

 Oriental origin, but I will not weary the reader 

 with further enumeration of such instances. Just 

 two more, however, before concluding, as I have 

 not alluded to the large group of the Arachnida. 



Two peculiar spider-like genera, viz., Galeodes and 

 Rhax> are found in Southern Europe. Both occur 

 also in North Africa, and in Western and a portion of 

 Southern Asia. As the whole family altogether has 

 an Asiatic character, I cannot agree with Mr. Pocock, 

 who considers them of European origin and believes 

 that they are migrating eastward. 



But not only terrestrial forms migrated to Europe 

 from Western and Southern Asia. Freshwater 

 species also took part in this great Oriental migra- 

 tion. 1 need only refer to the freshwater Crab 

 (Thelphusa fluviatilis), with which Southern Euro- 

 peans are familiar. It is the sole representative of a 

 large genus which ranges east as far as Australia and 

 southward to Madagascar and the Cape of Good 

 Hope. The European species is found in Turkey, 

 Cyprus, Greece, Southern Italy, Sicily, North Africa, 

 Southern Spain, Syria, and Persia. 



