A mapping of the world in regions indicative of the distribution of earthworms produces a result which is slightly different from the accepted division. North America, Europe, and Northern Asia so far as is known agree in having as their distinctive earthworms the family Lumbricidae, which is very nearly the only one represented in these parts of the world. The majority of the species are common to the two continents; there cannot, in fact, be a separation of Nearctic and Palaearctic; we must accept the Holarctic region of Professor Newton. The Ethiopian region, on the other hand, is quite as it is in other groups, being bounded to the north by the desert of Sahara. The Neotropical region is quite distinct, and includes Central as well as South America, and the West Indian islands, even the Bermudas. It is, however, a question whether the more southern portions of the continent should not be cut off from the rest and joined with New Zealand, to form an Antarctic region. In these two countries, and also in Kerguelen and Marion Islands, the prevailing genera are _Acanthodrilus_ and _Microscolex_. In America _Acanthodrilus_ is found nowhere but in the more southern regions of the southern continent, as well as in the Falklands and South Georgia. New Zealand is characterised by other genera of Acanthodrilids besides _Acanthodrilus_ itself; but the bulk of the species belong to the latter genus. _Acanthodrilus_ also occurs (three species only) in Queensland and at the Cape of Good Hope. _Microscolex_ is rather more widely dispersed, being found in other parts of America and in Europe, the island of Madeira (? accidentally imported); but it is undoubtedly chiefly concentrated in South America and in New Zealand. Apart from New Zealand, which, as already said, can only be doubtfully referred to the Australian region, the latter appears to form one with the Oriental region (to which, on account of its Perichaetidae, Japan should be added) of other writers. There is, so far as earthworms are concerned, no "Wallace's line" at all. The characteristic genera _Perichaeta_ and _Megascolex_ range from one extremity of the Indo-Australian region to the other. It is true that _Cryptodrilus_ and _Megascolides_ are limited to Australia itself (with the apparent exception of a species or two in America, for I can hardly separate _Argilophilus_ of Eisen from _Megascolides_); {373}but they are not at all well-defined genera, and indeed the generic distinctions of the whole family Cryptodrilidae are not in a satisfactory condition.