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Show 376 MR. F. E. BEDDARD ON THE [Apr. 19, suboesophageal gland, but the cells become smaller and more flattened, although they still contain the peculiar yellow granules. The vascular channels in the walls of the suboesophageal glands appeared to be less developed than in the calciferous glands ; I am disposed, however, to think that this was due to accidental causes. As shown iu the figure (Plate XXXIII. fig. 3) the contractile " heart " of this segment (h) gives off almost immediately after its origin from the dorsal vessel a conspicuous thin-walled vessel (h') on either side, which passes round tbe oesophagus, and ends upon the surface of the suboesophageal gland ; it is doubtless concerned with the blood-supply of the gland. § Vascular System. The principal vascular trunks correspond to those of most other intra- and post-clitellian worms ; in the oesophageal region there are five longitudinal trunks (I did not observe any lateral vessel), viz. (I) dorsal vessel, (2) supra-intestinal, (3) infra-intestinal, (4) supra-nervian, and (5) subneural. There are five pairs of " hearts" encircling the oesophagus: the first of these lies in segment 8, and connects the dorsal with the supra-nervian vessel; the lateral hearts of segments 10, 11, and 12 are also connected with the supraintestinal trunk : this did not appear to be the case with the heart of segment 9, although I am not perfectly certain about the point. The walls of the first four pairs of hearts are very muscular and thick ; this is not the case with the hearts of segment 12, which are chiefly concerned with the blood-supply of the calciferous glands of this segment. It is worth pointing out that Eudrilus agrees closely with Thamnodrilus (see P. Z. S. 1887, pt. i.) in the number of hearts, and in the fact that the three posterior are intestinal hearts, communicating as they do with tbe supra-intestinal vessel. The ventral oesophageal glands are supplied (see fig. 3) by a blood-vessel which leaves the supra-intestinal and dorsal trunk ; the blood is collected from these glands, and from the walls of the oesophagus generally into the subintestinal vessel. The supra- and subintestinal vessels are well developed in the region of the oesophagus, being chiefly concerned with the blood-supply of its walls. Each of the vessels (figs. 5, 6, 7) bifurcates in tbe neighbourhood of the suboesophageal glands. § Nephridia. The occurrence of these organs has already been noted by Perrier, who does not, however, give any account of their anatomy. His division of the Intraclitellians into two groups, which are characterized by the dorsal or ventral position of the nephridiopore, is clearly inadmissible, since the present species agrees with Tit amis and differs from other species of Eudrilus in the fact that the nephridia open by the ventral pair of setae. The nephridium itself (fig. 17) consists of a tubule of the ordinary structure and coiled upon itself in a very complicated fashion ; the |