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Show 1892.] SPECIES OF EARTHWORMS. 703 16. Ilyogenia africana, nov. gen., n. sp. A m o n g the specimens of Eudriloides durbanensis was an example of a totally different species-a fact which I only recognized after examining longitudinal sections of the head end of the worm ; the smallness of size, absence of pigment, and similarity in the position of the clitellum prevented m e from distinguishing them when alive. They belong, however, to totally different families; the species now to be described is a Geoscolecid. It has paired setae which show no recognizable ornamentation. I did not observe whether those upon the clitellum were in any way different from the rest. The clitellum commences in the xiith segment and ends in the xixth ; it is a little difficult to be precise about the actual beginning and ending. If we reckon as clitellum only that tract of epidermis where the " untere " and " obere Saiilenregion " of Claparede can be recognized, then the clitellum begins at the commencement of segment xiii.; but the epidermis covering segment xii. dorsally differs from that lying in front by the fact that the glands are elongated and very darkly stained; they are indeed the exact counterpart of the clitellar gland-cells in many aquatic Oligochaeta which I have examined when prepared in a similar fashion. These deeply staining cells contrast in that very particular with the clear and very faintly stained gland-cells of the segment in front. The clitellum is " saddle-shaped." The nephridia are paired structures ; the first pair are situated in segment iii. The funnels have the usual position and are not large. The nephridia themselves are without the terminal muscular duct; I observed the plexus formed by the " fine tubes " of the nephridium to which Benham has called attention in Microchceta. The external orifice of the nephridium is in front of the ventral setae; those belonging to segment ix. open just behind but quite independently of the spermatothecae. From the eighth segment, but more distinctly from the ninth, the nephridia are invested by a thick sheath of clear pyriform cells with deeply staining nuclei; the cells themselves are not much staiued. These cells, which cover the nephridia, are sometimes quite clear but more often have a vacuolate appearance. The alimentary canal presents the usual divisions ; there is, however, no trace at all of a gizzard-not even the slightly thickened tract of muscle which marks a portion of the oesophagus in Pontodrilus. The pharynx commences in the second segment, the brain lying rather hehind the transverse furrow which separates it from the buccal cavity, and therefore near to the posterior boundary of segment ii. The pharynx appears to occupy the third segment and a part of the fourth ; as usual, numerous retractor muscles are inserted into its dorsal wall. Masses of septal glands occupy the fourth to the seventh segment; those of the last segment are very much smaller; the masses of unicellular glands of successive segments are connected by fibrous strands which pass through the septa. The oesophagus passes straight back to the twelfth segment, where it opens into the intestine. It is nowhere ciliated, except just |