We will now contrast these conditions, which exemplify certain facts shown by the characteristic Oligochaeta of tropical Africa, with those which obtain in Europe. In this region of the world the prevalent and practically the only genera which need be taken into consideration in surveying the Oligochaetous fauna from the present point of view, are _Lumbricus_ and the genus _Allolobophora_ of Eisen which has been variously rearranged into genera and sub-genera known by the names of _Helodrilus_, _Bimastos_, _Octolasium_, etc. The structural differences which divide these genera and sub-genera are not great; in any case they do not exhibit such a wide range of variation from each other as do two such Eudrilid genera as _Stuhlmannia_ and _Hyperiodrilus_. We find the genera mentioned not only in Europe but extending themselves over more or less of Asia, even occurring in Japan; while the North American continent contains also representatives of the same. Not only do we find this community of genera over vast extents of country greater in diameter than the African continent, but there are also many species which range as widely or nearly as widely as the case may be as the genus to which they belong. Thus the species of _Allolobophora_ (we do not trouble about the newer sub-divisions as they hardly affect the facts to be emphasised), _A. caliginosa_, _A. longa_, _A. rubida_, _A. chlorotica_, _A. octaedra_, _A. constricta_, _A. beddardi_, _Lumbricus terrestris_, _L. castaneus_, have an enormously wide range over what is generally termed the Palaearctic region, extending also in some cases into the Nearctic. It is true no doubt that the majority, indeed perhaps all, of these are, like certain species of _Dichogaster_ mentioned above, among those forms termed peregrine which have the capability of living in every quarter of the globe to which they have apparently been conveyed by man. But there remain many species which have a very extended habitat in the northern hemisphere, and in any case the genera and the species are there truly indigenous and widely spread.