| OCR Text |
Show 208 MR. F. E. BEDDARD ON EARTHWORMS [Jan. 14, and P. hesperidum. I am able now to alter this list, by removing P. bermudensis, which I have received from Hong Kong l, and also adding to the first list P. violacea and P. sinensis, which I have received from Trinidad and Grenada, and to the second the two n e w species described in this paper. The first list will then contain eight species, and the second eight. Seeing the large number of species which have been in all probability introduced into the West from the East, it is in m y opinion by no means to be taken for granted that the genus Perichceta is indigenous in the West Indies and South America. I a m disposed to look upon it as a distinctly Oriental genus. ACANTHODRILUS MACQUARIENSIS, 11. Sp. Of several specimens of this apparently new species only two were sexually mature. It is a small species, measuring about an inch in length, and consisting of some 100 segments. The prostomium is incomplete, not dividing the peristomial segment. The setae are distant from each other, but not equally so. The two ventral of each side are more closely related than the two dorsal. The actual distances are much as indicated in the following scheme: Sx 1 S2 1 S3 If s4, for the anterior segments of the body. Behind the clitellum the distance separating the two ventral setae is about half that which separates the two dorsal. Towards the xviiith segment and on both sides of it the two setae of each ventral couple get closer together, and on the xvihth segment these setae are closer together than anywhere else. A similar convergence of the setae towards the segment bearing the male pores has been noticed in various species of the genus Microscolex. O n the xviith and xixth segments the ventral setae are altogether absent, beiug replaced by the penial setae. The nephridiopores open in front of seta 3. One of the two sexually mature individuals had no papillae; upon the other there were a pair of these structures corresponding in position to the ventral setae. One of them was evidently abnormally situated, for they were upon different segments, the right-hand one upon the tenth, the left-hand upon the eleventh segment. The clitellum occupies segments xiii.-xvi., commencing at about the middle of the former segment. It is continuous across the ventral surface except perhaps for the last of the segments over which it extends. The oviducal pores are paired, and upon segment xiv. each lies in front of seta 1. The male pores (on xviiith) are to the outside of seta 2. The spermiducal gland-pores correspond in position to the outer seta 1 Typical specimens, not doubtful P. hawayana ; see pp. 202-203. |
