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 _Rhododrilus_, _Leptodrilus_, _Maoridrilus_, _Neodrilus_, _Plagiochaeta_, _Pereiodrilus_, _Dinodrilus_, _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 _Notiodrilus_, that characteristic Antarctic form. In fact New Zealand would 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. Although the genus _Notiodrilus_ certainly, and _Microscolex_ possibly, extend into the tropical regions of America, Africa, and Australia, these species are but few, and the bulk of the species and of the allied genus _Chilota_ are restricted to the antarctic quarter of the globe; they also extend all over it, that is to say in the southernmost parts of South America, in the Cape region of Africa, in Kerguelen and the Crozet Islands, and in New Zealand, as well as in the Auckland Islands and other neighbouring islands. It is true that I have excluded New Zealand from this region on the grounds that it forms a debateable ground between it and the Indo-Australian. But apart from this part of the world the rest of the territories mentioned should be combined to form the antarctic region.