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Show 1897.] FROM SOUTH AFRICA. 339 on account of the series of longish spines which occur along the two edges. A higher power reveals the fact that the spines are really arranged in complete rows which entirely surround the shaft of the seta for the distal half to one-third. The actual extremity is free of spines. (2) Acanthodrilus arundinis, n. sp. Of this species there were four examples in the collection, of which three were fully mature with a clitellum. They were collected "in and under loose clods of dead sedges on edge of water. It is a slender and small species, measuring some 40 m m . in length. I counted 75 segments. The prostomium is incomplete. The clitellum, completely encircles the body and embraces half of segment xiii. together with segments xiv., xv., xvi. The spermathecal pores are conspicuous orifices lying ou the boundary lines of segments vii./viii., viii./ix., on a line with the outer of the two ventral setae. The spermlducal-glancl pores are highly conspicuous and lie in a position corresponding to the ventral couples of setae. The two pores of each side of the body are connected by a groove which passes to the outside of the ventral couple of setae of the xviiith segment. On the last segment of the clitellum there was (at any rate in two of the sexual specimens-I did not examine the third before slicing it for microscopical purposes) a single median genital papilla. The setce are arranged in couples. The distances between the individual setae vary somewhat in different regions of the body. Anteriorly the two setae of each ventral couple are about half the distance from each other of that which divides the two lateral setae. On the xvth and xvith segments the two ventral setae approach each other, and on the xviiith they are very close together. After this they again diverge, and on the rest of the body the proportions between the intersetal spaces are much as in the anterior region of the body. The gradual approximation of the ventral setae at the male pore is parallelled in that section of the genus Mlcroscolex which Eisen proposed to call Deltanla. On segments xvii. and xix. the ventral setae are replaced by the modified penial setae. The gizzard is but slight; it lies in segment v. The circular muscles, which are ordinarily so strong in this organ, are in the gizzard of the present species not much thicker than the lining epithelium. There appear to be no calciferous glands. The spermathecce are, as usual, two pairs ; they are globular thiri-walled pouches, each having two diverticula. The duct of the main pouch which leads to the exterior is very thick-walled and muscular, and into it open the diverticula. This duct was plugged with a mass of spermatozoa surrounded by a non-staining thick |