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Show 1892.] NEW SPECIES OF EARTHWORMS. 139 like the pore of the next somite, is in line with the chaetae " 4 pores in somites v., vii., ix., xi., xiii., xv., &c. are in line with chaetae "3"; those of the even-numbered somites are in line with chaetae " 4 " ; but in the case of somites vi., viii., x., xii., I did not actually see the pores, as the dorsal body-wall in this region of the body had been injured in dissecting the worm, but there is no pore in either of these somites in line with either of the other chaetae. [In P. heteroporus, the nephridiopores of somites iii., iv., v., vi. are in line with the third chaetae, those of vii., ix., xi., &c. with the fourth chaetae, and those of viii., x., xii., &c. with the second chaetae, with some divergence from regularity in certain somites.] The male pores are on somite xviii., just between the first and second chaetae ; but in the immature specimen, as I have mentioned, there is a pair of papillae in this position, which carry the pores; the papillae in the fully developed individual being continuous with the rest of the glandular modification of the clitellum. With regard to P. heteroporus, Perrier states (p. 255) " il nous semble que les orifices males etaient accompagnes chacun d'une papille en avant et en arriere," but owing to the state of preservation of the worm he was uncertain on the point. The figure (Plate VII. fig. 1) which accompanies the present paper might suggest these papillae, but the slight pit represented between somites xvii. and xviii. is not the male pore, which lies on the slight papilla on somite xviii. I was unable to see the pores in somite x. which Perrier regarded as those of his " oviducts "; they, in fact, do not exist in the present worm. With regard to these pores, his figures are not in agreement with one another. The spermathecal pores (which are in line with chaetae " 2," at the anterior margin of somites vi. to ix.) and oviducal pores (on somite xiv.) are not visible in surface view. There appear to be no dorsal pores; this is one of the few points in which my specimen differs from P. heteroporus. Internal Anatomy. The septa bounding posteriorly each of the somites v. to xi. are considerably pouched centrally, so that the organs in these somites are carried backwards in such a way that they appear to occupy a more posterior position than they actually have ; the septa behind the somites viii. to xii. are slightly stronger than the others (Plate VII. fig. 3). The nephridia conform to the usual type ; the coiled tube presenting the three regions which I have described1 in those of Lumbricus and which appear to be pretty generally present in " meganephric " Earthworms. The muscular region or " bladder " is very large, and differs in size in the two series of nephridia. The funnel has the normal structure and position-i. e. it is praeseptal. The genital organs have the following arrangement, as determined 1 " The, Nephridiurn of Lumbricus,"' Quart. Journ. Micr. Sci. xxxii. |
