| OCR Text |
Show 672 MR. F. E. B E D D A R D ON N E W [Dec. 20, iv., v., vi. are triannulate, the middle annulus being much the narrowest; segments vii., viii., ix. are very much wider (antero-posteriorly), but still triannulate; so, too, are the segments which immediately follow, though much narrower. After the clitellum the segments continue to be triannulate. The clitellum extends from segments xiii.-xix.; it is at first complete, extending right round the body; but on segments xvi.-xix. there is a ventral median area without any glandular modification. The atrial pores are upon very conspicuous papillae; the two of each side of the body are connected by a longitudinal groove, which is not straight but has a semicircular outline, the convexity being dorsal. The oviducal pores are just in front of the ventralmost seta. The setae are rather distant from each other; a somewhat greater distance separates the two lateral setse. I have not seen any dorsal pores. The pharynx occupies the first four segments of the body; the gizzard is very elongated, with parallel margins ; it measures 6'5 m m. in length ; the gizzard occupies two complete segments, the fifth and the sixth. The oesophagus bears in segment xvii. the single pair of calciferous glands, which present the appearance of an oval swelling of the oesophagus itself. The intestine commences in the xixth segment. The septa of some of the anterior segments are, as is so constantly the case with Earthworms, strengthened and bound together with thin muscular strips which occasionally pass through one septum to reach another lying behind it; the number and appearance of these septa is illustrated in the accompanying drawing (woodcut, fig. 2, p. 673). The first septum, which is thin and transparent, divides segments iv./v.; it is traversed by a large number of muscular threads which bind the pharynx to the parietes: the next septum is also thin and delicate in texture ; it is attached at the end of the first third of the gizzard ; a good number of the threads which bind the pharynx to the parietes pass through it. The following seven septa are thickened ; the last of them therefore bounds the thirteenth segment anteriorly. The dorsal vessel is completely double; the two tubes of which it is composed retain their individuality where they pass through the intersegmental septa. The dorsal vessel is, however, at first a single tube; it is not until the seventh segment that it becomes double. In this segment commences the supra-intestinal vessel, which is large and very conspicuous. In segments x., xi., xii., xiii. are the four pairs of dilated hearts; in a few segments, anterior to the tenth, are more delicate peri-cesophageal vessels. There are, as iu Octochcetus multiporus, a pair of large nephridia lying close against (in front of) the first septum ; from each of these a slender duct was traced forwards which opens, it may be inferred, into the buccal cavity ; I did not, however, succeed in seeing the actual orifice. In the rest of the body the nephridia are also constructed upon the plan which is characteristic of Octochcetus multiporus; the tufts appear to be massed chiefly round the setae. Both testes and ovaries occupy the usual segments, but the gonads |
