A very interesting fact offers itself first of all in considering this family of earthworms. The Geoscolecidae are one of the only division[2] of the Oligochaeta terricolae which are generally found to be without those characteristic series of pores in the middle line of the back known as the dorsal pores. They are thus eminently suited for an aquatic life; for it is to be supposed from the fact that the purely aquatic 'Limicolae' are also without these pores that their existence is prejudicial to a water-living worm. Indeed the entrance of water into the body-cavity would presumably be dangerous to the worm. The Geoscolecidae are thus already marked out, as it were, for an aquatic life. No modification is here necessary for them. It is also to be noted in this connection that various species of the genus _Notiodrilus_ to which reference has been made as a partly aquatic genus have no dorsal pores. They too are thus fitted for at least an amphibious life. [2] In the Eudrilidae also these pores are very frequently absent. The rule however regarding the absence of dorsal pores in the Geoscolecidae is not absolute. A few species and among them two species at any rate of the aquatic genus _Sparganophilus_ have a few pores between some of the anterior segments which have been spoken of as 'neck pores.' They are not, it is to be believed, of a different nature from the generally distributed dorsal pores of other worms but are in fact limited to the 'neck' region. There are no other obvious characters of the family Geoscolecidae as a whole which might be regarded as fitting them for a purely aquatic life.