382 MR. F. E. BEDDARD ON THE [Apr. 19, 



In the present species, as well as in Eudrilus hoyeri^, the 10th 

 and 11th segments are occupied by a pair of thin-walled vesicles 

 (woodcut, fig. 1), situated close to each other on either side of the 

 nerve-cord and largely concealed by the superjacent vesiculae seminales. 

 These vesicles in both species alike were filled with a chalk-white 

 mass, which rendered them far more visible than they would have 

 been if void of contents. In Eudrilus boyeri I was unable to ascer- 

 tain the nature of these structures, and accordingly have not referred 

 to them in my notes on the anatomy of that species. M. Perrier 

 gives no description or figures of any such structures in his species 

 of Eudrilus. I was at first inclined to regard these structures as 

 spermathecae, with which they have not a little resemblance ; my 

 sections, however, show that they are really the much-dilated extre- 

 mities of the vasa deferentia just before they open into the funnel. 



Fig. 11 (Plate XXXIII.) illustrates a transverse section through 

 one of these structures, and shows the continuity between the cavity of 

 the vesicle and the terminal funnel. The funnel of the vas deferens is 

 (fig. 1 1, c), as usual, a much plicated membrane, composed of ciliated 

 cells with an underMng layer of muscular fibres, among which are 

 numerous blood-capillaries ; the terminal vesicle of the vas deferens 

 (fig. 11,6) has exactly the same structure ; it is lined by a single row 

 of cubical ciliated cells ; in the interior of each of these is a distinct 

 nucleus. Outside the layer of ciliated cells is the muscular coat, com- 

 posed of fibres running in difi'erent directions ; the thickness of the 

 muscular coat is not much greater than that of the cellular layer. 

 The anterior pair of vasa deferentia funnels, as sliown in the figure 

 (fig 11), project into the interior of the vesicula seminalis ; there is, 

 however, a space left between the masses of spermatophores and the 

 ciliated cells ; the whole of the vesicle of the vas deferens, with the 

 exception of the under surface, is completely surrounded by the vesi- 

 cula seminalis ; the delicate fibrous wall of the latter appears to be 

 here in actual contact with the muscular wall of the vesicle ; there is, 

 at any rate, no space left between the masses of spermatophores and 

 the wall of the vesicle. The posterior pair of vas-deferens funnels 

 appear at first sight to be completely free from all connection with 

 the vesiculae seminales of their segment. The vasa deferentia, how- 

 ever, do not open fieely into the body-cavity, but into a delicate 

 fibrous i'ac (which encloses the ventral blood-vessel, and is conse- 

 quently perforated by the lateral "hearts" of this segment, which 

 unite the ventral with the dorsal vessel). This sac is median and 

 unpaired ; it is connected with a short diverticulum on either side, 

 which contains the testis ; groups of spermatophores are found in 

 the interior of the sac ; and although I have not succeeded in tracing 

 its continuity with the vesiculas seminales, I have little doubt that 

 the separation is only secondary, if not altogether accidental ; it 

 corresponds to the median portion of the vesiculse in segment 10. 

 The vasa deferentia remain separate for the whole of their course ; 

 the two vasa deferentia of each side only become united within the 

 lunic*of the prostate gland. They are furnished with an unusually 



' P. Z. S. 188fi, p. 302. 



