The sub-family Hormogastrinae which contains but a single genus _Hormogaster_ is remarkable for being limited in range to the Mediterranean coasts. The genus is mainly distinguished by possessing three gizzards; otherwise it is not very different from the sub-family just described. The African and Madagascar forms are associated (together with a few Asiatic forms) into a third sub-family Microchaetinae. These worms frequently possess a considerable number of very small spermathecae in segments XII, XIII or thereabouts instead of the usual paired arrangement. They have too very often glands connected with the enlarged setae already mentioned which are however (in the genus _Kynotus_ at any rate) usually in front of the clitellum. The latter organ, contrary to what we find among the Geoscolecinae, is often behind the point of orifice of the male pores. This is so with _Kynotus_. [Illustration: Fig. 9. Ventral view of _Polytoreutus Kilindinensis_, head end (x 2). _p_ papillae, [M] male pore, [F] female pore.] The last sub-family, Criodrilinae, has but three genera _Criodrilus_, _Sparganophilus_ and _Alma_. These worms do not show any very marked differences from other Geoscolecids. _Alma_ is noteworthy for the facts that the male pores are borne upon long processes of the body which bear specially modified setae and that one species at any rate has gills. [Illustration: Fig. 10. Ventral view of _Polytoreutus finni_, head end (x 2), lettering as in fig. 9.] Another type of structure is offered by the Eudrilid earthworms which form rather a restricted family. These worms are as a rule quite easy to distinguish by their external characters only. For the apertures of the spermathecae and sperm ducts are apt to be very large and conspicuous. They are also generally unpaired, a character which is however not confined to the Eudrilidae; for there are Megascolecids, such as _Fletcherodrilus_, and Geoscolecids in which the same unpaired character occurs. The principal feature of the family is that the ovaries are commonly enclosed in sacs--comparable to the sperm sacs which frequently envelop the spermaries in other earthworms--and that these sacs not only contain the mouths of the oviducts but are directly continuous with the single or double spermatheca. This is usually a large sac, always single or consisting of one pair only, which opens on to the exterior close to the oviducal pores; these spermathecae in the Eudrilidae are not comparable to the spermathecae of other earthworms; for they are in a way comparable to the sperm sacs, being formed as outgrowths of the septa. There is some variation of structure within the family. In a number which are associated into a sub-family Eudrilacea there are two paired calciferous glands and a single unpaired one, while the paired nephridia open by a large pore on to the exterior. In a parallel sub-family, the Pareudrilacea, the calciferous glands are