In the worms of this family the male pores are usually upon the tenth segment but sometimes upon the eighth or eleventh. And in addition to a pair of funnels in the antecedent segment there is also commonly a second pair in the same segment as that which contains the external pore. The two sperm ducts however open into the same distended atrial cavity before opening on to the exterior. In _Lamprodrilus_ however each sperm duct opens by its own separate atrium on to the exterior and in two consecutive segments. In _Teleutoscolex_ there is but one pair of funnels opening into the same segment with the atrial pore. Near perhaps to the Lumbriculidae comes a very small family indeed, that of the Alluroididae. So small is it that it consists of but a single genus _Alluroides_ of which there are two species _A. pordagei_ and _A. tanganyikae_. Both of these species were described by myself, one of them from but a single specimen, the other from only two. Both species--and the name of one denotes the region--are from eastern tropical Africa. The Tanganyika worm is purely aquatic; the other species was found in a swamp of the mainland opposite to Mombasa. This remarkable genus has a pair of spermaries in segment X; but the ovaries are as in earthworms in the XIIIth segment. The male pores are upon that segment also, _i.e._ further back than in the aquatic worms. The spermathecae open close to the median dorsal line of the body in one species; in _A. tanganyikae_ there is but one spermatheca which opens actually in the dorsal median line between segments VIII and IX. This family seems to come nearest to the Lumbriculidae but has also obvious points of likeness to the terrestrial Moniligastridae. It fully deserves a separate family, which was founded for it by Dr Michaelsen.