IX] GEOGRAPHICAL DISTRIBUTION 137 



important still this region has confined to itself the 

 family Moniligastriclae ; for a species described some 

 years ago by myself from tlie Bahamas is doubtless 

 an introduced form. We have a complete absence of 

 indigenous Lumbricidae and Geoscolecidae excepting 

 the aquatic Glypliidrilus of the sub-family Micro- 

 chaetinae. It is true that by taking isolated tracts, 

 even large tracts, of this great regional expanse a 

 sub-division into well characterised regions can be 

 apparently recognised. But in taking such a step we 

 shall be confronted with the curious fact that it is 

 rather neighbouring than widely remote sub-divisions 

 which present the greater differences. 



If we compare for example India and New Zealand 

 we find in common such striking genera as Octochaetus, 

 Ho2)lochaetella and Diporochaeta ; whereas these 

 genera are absent from the intervening islands of 

 the great Malay archipelago. On the other . hand 

 Australia differs from the comparatively neighbouring 

 islands of Borneo and others by the absence in those 

 islands of the characteristic Australian genera such 

 as Megascolex, XotOHColex, Fhttellus etc. which are 

 in their turn found in India. It is facts like these 

 which render very difficult the apportioning of the 

 tracts of country forming the eastern hemisphere 

 into separate regions. 



There is no doubt that the Malay archipelago and 

 the adjacent coasts of Asia up to Japan ditter from 



