some new Species o/Dianida. 507 



I wish to point out here is tliat the structure of the copulary 

 vesicles in the species of Drawida examined enables them to 

 act as magazines of sperms received during copulation and 

 for expelling them for fertilisation later. On hypothetical 

 grounds, too, it is rather difficult to conceive the sperms 

 working their way up all along the most tortuous course of 

 the spei-niathecal duct, to be housed temporarily in ampulla, 

 and to be returned through the same passage. On examin- 

 ing the material in my [)ossession, I should not hesitate to 

 adopt the view that the ampulhi of Drawida, like that of 

 the family Megascolicida;, has a secretory function, while the 

 atrium and its diverticula act as storing organs of sperms, 

 besides aiding in copulation. 



Testes and iSpenn-sacs. — The most important feature of the 

 male reproductive organs of this species to which I should call 

 attention is the occurrence of two pairs of sperm-sacs, a fact 

 not hitherto noticed in any of the numerous species already 

 described. The first pair are vei'y large, yellowish^ massive, 

 in-egularly subspherical bodies suspended l)y the septum 8/9 

 (PI. XV. fig. 3 a). They usually occupy segments 9, 10, 11, 

 and 12, and are never constricted by the se})tal walls, which, 

 however, are extremely thin in these somites. Frequently 

 they leave their proper position and descend backwards up 

 to segment 18, and wherever placed they repose on the 

 oesophagus and are connected to the septum 8/9 by the drawn- 

 out tubular extension of the wall of the mesentery, and in 

 the succeeding segments they are invested with septal 

 peritoneal outpushings. In somite 9 the oesophagus and 

 other organs are contained in the cavity between the double 

 wall of the thin septum 8/9, and this cavity oC the mesenterial 

 sac is continuous all round them. Each of the posterior or 

 second jjair of sperm-sacs is really a double^ white, tubular 

 vesicle with a velvety api)earauce. They lie in somite 10, 

 liaving very early in development detached themselves from 

 the septum 9/10. They are bent in the form of a query- 

 mark, and usually lie hidden below the oesophagus, 

 occupying segments 9 and 10. In -one form, which has 

 developed clitellum over 4^ segments, they are very long, 

 and extend as far behind as segment 14. Rarely the tubular 

 vesicles on the same side are unequal. 



There are certain interesting facts connected with the micro- 

 scopic structure of these two kinds of sperm-sacs (PI. XVll. 

 figs. 10 a, 10 h). A firm membrane, the mesentery of septum 

 8/9, encloses the anterior testis, and the rosette belonging to 

 somite 9 and the lower hinder surface of the sacs is bevelled 

 and bright yellow in ap[)earance, which marks the position 



