780 CONTRIBUTION TO AUSTRALASIAN OLIGOCH^TA, I., 



one on each side of the body. Following the course of the funnel- 

 structures, it is seen that they pass into tubes which run towards 

 the postero-ventral region of segment xiii., and eventually through 

 the posterior wall of that segment to reach the spermathecal 

 chambers. That which joins the ventral chamber passes into a 

 wide tube, which is found to run vertically upwards, and become 

 confluent with the postero-ventral portion of that chamber. The 

 wall of the tube consists of epithelium of tightly packed, cuneate 

 cells with a ventrally placed nucleus, this epithelium being 

 surrounded by circular muscle-fibres much more strongly developed 

 than in the case of the spermatheca itself. The spermathecal 

 tube connected with the other funnel, after reaching segment xiv., 

 in company with that connected with the ventral spermathecal 

 chamber, passes round the posterior border of the lower sperma- 

 thecal chamber, between the oesophagus and the anterior extremity 

 of the intestine, to open into the postero-ventral margin of the 

 upper spermathecal chamber. The spermathecal chambers each 

 contain a fusiform mass, consisting of a linear aggregation of 

 spherical bodies, and apparently representing spermatophores. 

 At first one feels inclined to ascribe to these chambers the 

 function of egg-sacs, and to interpret the masses of spermatophores 

 as aggregations of ova. Sections, however, show clearly that 

 they are not ova, and this evidence is assisted by the presence of 

 a disappearing duct connected with the ventral chamber, and 

 corresponding in position with the spermathecal duct of the 

 Phreodrilidce. Further, so narrow is the duct leading from these 

 chambers to the funnel in segment xiii., that the passage of ova 

 along them would be as impossible as that of the ova of Nereis 

 through the nephridia. We have, then, in Astacopsidrilus, a 

 unique character in connection with the spermathecal chambers, 

 inasmuch as (1) they are tending towards fusion and the forma- 

 tion of a medial impaired sac, due to the moving upwards of the 

 spermatheca of the left side, and connected by a wide duct-like 

 passage with the dorsal side of the spermatheca of the right side; 

 (2) the absence of a passage communicating directly between 

 these chambers and the exterior, and the entire absence of any 



