138 EARTHWORMS AND THEIR ALLIES [ch. 



both India and Australia by the almost entire limita- 

 tion of the genus Pheretima to them ; but we cannot 

 intercalate a region in the middle of another geo- 

 graphical area in this fashion ! 



The limitations of this great Indo-Australian 

 region now demand consideration. The chief difficulty 

 is offered by the islands of New Zealand and by some 

 of the smaller islands lying far from but still in the 

 neighbourhood of New Zealand. Are we to include 

 New Zealand in this region ? There is no doubt that 

 the northern island of New Zealand is much nearer 

 to Australia in its earthworm fauna than is the 

 southern island. There are, it is true, a number of 

 genera peculiar to New Zealand, which are Rhodo- 

 drilus, Leptodriltis, Maoridrilus, Neodrilus, Plaglo- 

 chaeta, Pereiodrilus, Dlnodrilus, Dinodriloides, but 

 these do not represent the whole of any family or even 

 sub-family and they have all of them near relations in 

 other parts of the region as has been pointed out 

 even to the peninsula of India itself Again New 

 Zealand contains members of the genus Notiodi'ilus, 

 that characteristic Antarctic form. In fact New 

 Zealand Avould appear to be a transitional zone 

 between an Indo-Australian and an Antarctic region. 



The last region into which the world can be 

 divided according to its fauna of earthworms is an 

 Antarctic. I am of distinct opinion that this region 

 is quite necessary in spite of the views of some others. 



