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Show 6Q MR. F. E. BEDDARD ON [Feb. 4, is merely an abnormality of no special interest; on the other hand it occurred in both specimens, the only ones which I possess of this species. If a structural peculiarity is found in two specimens selected at random, there is, as it appears to me, considerable probability in favour of the structure being a normal one ; at the same time an asymmetry of this kind is most surprising in so typically a bilaterally symmetrical worm as Perichceta. I mention the fact therefore for what it is worth, without venturing to commit myself to a definite opinion as to whether it is normal or abnormal \ The sperm-sacs in both examples were limited to a single pair of large greyish kidney-shaped bodies attached to the anterior mesentery of segment 12, the last of the three specially thickened mesenteries. Lying upon each of these (again in both specimens), but attached separately to the mesentery, was a pedunculated sac (Plate V. fig. 7) of a brownish colour entirely filled with Gregarines. I am not at present able to say whether this sac is a part of the sperm-sac pathologically altered by the presence of these parasites or not. The ovaries are large and situated in the usual position in segment 13. In the next segment are a pair of bodies of similar shape and occupying an exactly corresponding position, which I regard as receptacula ovorum. PERICHCETA VAILLANTI 2, n. sp. Of this new species I only have a single example; like P. biseriatis it comes from Manila, and was collected near that town by Mr. Herbert Barwell, to whom my thanks are due for a large number of Earthworms collected in Luzon. The colour (in alcohol) is a yellowish brown, the yellow tint being particularly marked upon the clitellum. The prostomium is small and does not extend far over the peri-stomial segment. The setce form a continuous row round each segment. The male generative pores are upon the 18th segment. There are no genital papillce. The clitellum occupies segments 14-16 inclusive, and as in other species of Perichceta is developed all round the body; there are no setae upon it. The oviducal pore is single and median upon segment 14. Dorsal pores are present. The apertures of the spermathecce are very conspicuous on the interspaces between segments 5-6, 6-7, 7-8, 8-9. There are no specially thickened mesenteries at all. The nephridia form, as in other Perichceta^, a series of scattered tufts. 1 In a preliminary note in the ' Zoologischer Anzeiger,' Bd. xii. no. 318, I erroneously stated that the doubling of the spermatheca affected that of the 8th segment in both cases. 2 Named after M . Leon Vaillant. |