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Show 300 MR. F. E. BEDDARD ON NEW OR [May 18, The individual in question agreed in every other respect with P. indica, and the difference in the number of segments constituting the clitellum appears to m e rather as an indication that this structure is subject to some variation in the same species than a mark of specific distinctness. With regard to the dorsal pores, they are present in m y specimens in all the segments following the clitellum, as stated by Horst; I find, however, that the posterior border of the clitellum is not only marked by a dorsal pore, but the anterior border also, and that there is yet another pore in front of this ; this latter appears to be the first. In all other respects m y specimens agreed with Horst's description of Perichceta indica, and 1 believe them to be identical. I need not describe the organs of the body severally, as I was unable to detect any points of difference. 2. PERICHCETA HORSTI, n. sp. In a collection of Earthworms sent to me from Manila by my friend Mr. H. E. Barwell were a considerable number of specimens of a Perichata which I regard as of a new species. I dedicate it to Dr. Horst, whose work in this department of Zoology is well known. It is a small species, the largest individuals measuring only about 2 inches in length. The external characters afforded by the genital papillae serve to distinguish the species ; although the value of these characters is well known, it is often impossible to make use of them, as the genital papillae are not always present to the full number even in worms which are in other respects sexually mature. Out of seven or eight individuals which I have examined and dissected, one or two had very many more genital papillae than the rest ; in the absence of evidence to the contrary, I regard these specimens as being in this respect fully adult. The genital papillae are placed in the neighbourhood of the male generative pores as in P. affinis ; but instead of there being only a single pair to each segment, there are three distinct papillae placed at equal distances from each other and within the circle of setae. These are present on the two segments which precede the eighteenth and on the four segments which follow it ; on the eighteenth segment there is naturally only the median papilla present, the genital orifices themselves occupying the position of the outer papillae. In Perichceta biserialis and in P. juliani, according to Perrier1, there is some resemblance in the disposition of the genital papillae. to the condition which is characteristic of the present species; in both of the former there are a pair of genital papillae corresponding in position to the male reproductive pores and occupying a variable number of segments following the 18th. I have myself had the opportunity of examining a number of specimens of a Perichceta from the Philippine Islands, which I refer to the former species from the fact that the ventral setae are separated by a considerable interval and are of considerably greater size than the remainder, and that 1 Perrier, Comptes Rendus, loc. cit. |