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Show 1906.] WORMS OF THE THIRD TANGANYIKA EXPEDITION. 215 of the Megascolecid series and as thus possibly effecting a junction with the highly specialised Eudrilids, which are regarded by Bosa and Michaelsen as forming one family with the Megascolecidae. This point of view, to which I have not myself adhered in the past, is, I admit, strengthened by certain facts which I shall proceed to describe. The ovary does not lie absolutely freely in the cavity of segment xiii. A sheath of delicate muscles is prolonged forwards as a tube which possesses a narrow lumen and opens finally by a mouth into the cavity of segment xiv. The lower edge of this mouth is thickened by an increased development of muscular fibre and calls attention to the tube. It appears to m e that this tube is the equivalent of the delicate sac and tube leading from it which occurs in Eudrilus and in Stuhlmannia &c. (see m y figure of the female reproductive system of Eudrilus in P. Z. S. 1902, vol. ii. p. 93, and of Stuhlmannia, ibid. 1901, vol. i. p. 354). This tube leads from the sac which involves the ovary to the spermathecal sac. As the latter is developed at least in Eudrilus out of the intersegmental septum, and presumably in Stuhlmannia and other Eudrilids, there is no difficulty in comparing an open tube in Ocnerodrilus with a tube opening into a sac in Eudrilus &c. I may conclude with a definition of this new species * :- OCNERODRILUS (ILYOGENIA) CUNNINGTONI, sp. n. Length about 38 mm. Setce strictly paired, bifid at extremity. Clitellum saddle-shaped, xiv.-xviii. (Esophageal pouch but little developed, bifid at end. Last pair of hearts in xi. Dissepiments v./xii. thickened. Sperm-sacs in ix. and xii.; masses of sperm in x. and xi. Atria rather long, extending in the direction of the tail, vnth a distinctly separated muscular duct. Made pores opening upon a papilla near to ventral pair of setce, which are not aborted. Oviduct without receptaculum ovorum. Spermathecce large and oval, with narrow duct, sharply marked off from pouch. Hab. Lake Tanganyika. Alluroides tanganyikae, sp. n. Of this new species I a m able to give but an incomplete account, as the collection contains but a single individual. This was mounted entire upon a slide in Canada balsam, and I can only therefore give an account of external characters and of a few internal features which wTere visible through the thin body-wall. I refer it to m y genus Alluroides t by reason of the position and the structure (so far as I could make it out) of the reproductive organs, and it possesses no character which militates against this placing, as will be evident from the following details which I am able to * I do not mention generic and subgeneric characters as defined by Michaelsen. I suspect, howevei*, that the position of the last heart is a generic character, though not used by him. f " A Contribution to our Knowledge of the 01igocha?ta of Tropical Eastern Africa," Quart. Journ. Micr. Sci. vol. xxxvi., n. s. p. 244. |