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Show 342 MR. F. E. BEDDABU ON EARTHWORMS [Mar. 16, (5) Acanthodrilus excavatus, n. sp. This species comes from Knysna Forest, " in and under rotten wood, leaves, &c." It is a small slender species, measuring 48 mm. by 1*5 or 2 m m . I counted 90 segments in the individual selected for measurement. It is not unlike both A. arundlnis and A. sclaterl in general appearance, but may be distinguished at a glance from either of these by the deep excavation upon the' segments which bear the three pairs of male pores ; it is this peculiarity which suggested the specific name. The prostomium is incomplete, and the other external characters are those of the majority of tbe Cape species. There are, however, so far as I could make out, no genital papillce. The male pores, as already mentioned, lie in a deep excavation which is bridged over by ridges connecting the tw^o spermiducal pores of each pair with each other. I studied the anatomy of the worm by longitudinal sections. The clitellum extends from segment xiii. to segment xvi. The gizzard is slight, as in the two species with which I specially compare the present. There are no calciferous glands, and the intestine commences in segment xvii. Though there are no special calciferous glands, the oesophagus is moniliform in segments xii.-xiv., and its walls are there rather older and exceedingly vascular; in those segments too the supra-intestinal vessel was especially clear. The spermathecce have each a single long and sausage-shaped diverticulum. The sperm-sacs are in segments ix.-xi., and, as appears to be always the case when the last pair of sperm-sacs are in the xith segment, there is but a single pair of testes and vas deferens funnels ; these lie in segment x. (6) Acanthodrilus sclateri, n. sp. This is another small and slender species. The specimen selected for measurement was 45 m m . in length. There were no genital papillae. Tbe setce do not appear to converge at the male pores as in some other species of the genus described in tbe present communication. The prostomium is incomplete ; it is not always easy to be certain about the arrangement of the prostomium in these small Acanthodrill; so the remarks made here will apply to other small species, such as A. arundlnis &c. The grooves which bound the prostomium where it impinges upon the first segment of the body cease abruptly and are not continued as far as the furrow which separates that segment from the second. In some specimens of this and the other small species it appeared to me that the two furrows by which the prostomium is continued over the first segment met a little way in front of the line dividing that segment from tbe one following. The clitellum occupies segments xiii.-xvi. |
