I8S6.] MR. F. E. BKDDARD ON A LARGE EARTHWORM. 1 71 



(r/), which is a single tube, and not composed of two separate or 

 incompletely fused halves as in A. multiporus ^ and other Earthworm^, 

 communicates with the ventral vessel by seven transverse hearts (h) 

 situated in segments 8-14 inclusive — a pair to each segment. The 

 first three pairs are of less calibre than the following four, and appear 

 to arise simply from the dorsal vessel ; the four posterior pairs of 

 hearts communicate also with a small supra-intestinal vessel, which, 

 as shown in the figure {sn), lies beneath the dorsal vessel but above 

 the intestine ; in the anterior part of the body a pair of lateral vessels 

 (/) supply the body-wall; in the 11th or 12th segment these vessels 

 pass beneath the intestine and unite to form a single subintestinal 

 vessel. This vessel appears to be continuous posteriorly with a 

 vascular space within the walls of the alimentary canal. Each of 

 the two anterior pairs of hearts supplies the spermatheca of its 

 own segment ; a strong branch arises from the vessel just before 

 it unites with the ventral vessel, and a corresponding branch from the 

 latter is also distributed to the spermatlieca. 



Body-cavity. — The body-cavity, as in all other Earthworms, is 

 divided into segments by mesenteries which extend from side to side 

 of the body ; in the six anterior segments the mesenteries are more 

 or less distinct, but there are in addition a number of muscular 

 bands and tendinous-looking threads which bend the pharynx down 

 to the body-wall, often passing through the mesenteries on their 

 way ; the gizzard and a portion of the anterior region of the 

 oesophagus are only attached to the body-wall by a very few slight 

 threads, mesenteries being absent in this region of the body. The 

 mesentery which bounds the tenth segment behind and the succeeding 

 four mesentries are specially thickened and muscular. 



Nephridia. — There is a very considerable variation in the cha- 

 racters of the nephridia in this genus, and I have already^ referred 

 to what has been written on the subject. In the present species 

 the nephridia (fig. 6, li) are very conspicuous, especially in the anterior 

 region of the body as far back as the 19th segment or thereabouts; 

 in the posterior segments they are present but appear to differ 

 slightl)', principally in size, from the anteriorly placed nephridia. 

 The external apertures are plainly visible in front of the dorsal pair 

 of setai in all the seta-bearing segments of the body ; that is to say, 

 the first segment of the body appears to be without nephridia and 

 cnly this segment. The glandular portion of the nephridium forms 

 a closely packed tuft of tubules which has much the appearance 

 of the nephridia in those species of Perichceta^ in which these 

 organs have been described ; this glandular tuft lies in the region 

 of the ventral pair of setae and close to the mesentery which forms 

 the anterior wall of its segment ; the nephridium communicates with 

 the exterior by a long, widish, thin- walled duct. 



1 See F. E. Beddard " On the paired Dorsal Vessel of certain Earthworms." 

 Proc. Eoy. Phys. Soe. 1884-5, p. 424. 



^ P. Z. S. 188.5. p. 822. 



^ E. g. Periohci-ta indica, Hoi-st, Niederl. Arch. f. Zool. Bd. iv. (1879), 

 pi. viii. fig. o, .r. 



12* 



