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Show 170 MR. F. E. BEDDARD ON W O R M S [Feb. 16, for and might very easily escape attention; the muscular duct of the atrium becomes very narrow just before it opens into this sac. PERICHCETA MAURITIANA, n. sp. In August of last year I received from Kew a number of living Earthworms which had been accidentally imported from Mauritius; they proved on examination to belong to two distinct species : one is a tlrochceta, indistinguishable, so far as I can see, from Urochceta corethrura ; the other is a Perichceta belonging apparently to a new species. At present one species of Perichceta is known to occur in Mauritius; and a second, although described from Australia, is believed to be indigenous to Mauritius. The first is Perichceta mauritii of Kinberg, which cannot be satisfactorily identified ; the second-Perichceta peregrina-has been lately described by Mr. Fletcher1, and so cannot be confounded with Perichceta mauritiana, which comes much nearer to Perichceta robusta from the neighbouring He de France. The colour of the living worms was reddish brown, with a pale greyish-brown clitellum. Their habits are those of other species of Perichceta. The length of the largest specimen, after preservation with corrosive sublimate and alcohol, is 80 m m. The number of segments is 85. The clitellum occupies the usual segments ; the last segment of which it is composed has a short row of setae in the middle ventral line, as in Perichceta bermudensis. The oviducal pore is single and median upon segment xiv. The atrial pores are in the line of setae of segment xviii. ; the setae are interrupted for a short distance on each side of both apertures. The genital papillce are restricted to the neighbourhood of the atrial pores. There are three on each side, lying below and to the inside of the atrial pores. The gizzard lies in segments viii. and ix.; it apparently does not extend, as this organ so often does in other species of Perichceta, into segment x. The usual pair of cceca are present, which originate from the intestine in segment xxvi. and extend forwards to the anterior boundary of segment xxv. There are two pairs of spermathecce in segments vii. and viii. The diverticulum is as long as, or perhaps rather longer than, the spermatheca itself. It consists of a slightly sinuous tube with a globular extremity. There are two pairs of receptacula ovorum (Plate X. fig. 5), both of which have the form which seems to be so generally met with in this genus of Earthworms. The organ is oval, with a long tail directed towards the median ventral line. The receptacula ovorum are attached to the front wall of segments xiii. and xiv. The anterior pair lie above the ovaries. 1 "Notes on Australian Earthworms. Part II.," Proc. Linn. Soc. N. S. W . ser. 2, vol. i. p. 969. |