STEUCTUEE OP TWO NEW GENEEA OP EARTHWORMS. 267 



that most probably the sacs in question are simply extensions 

 of the egg-sacS; inasmuch as there is no definite break between 

 them and the egg-sacs; the trabeculse which divide up the 

 interior of the egg- sac into a series of more or less isolated 

 compartments^ as in other earthworms^ get gradually less and 

 less until the cavity becomes perfectly smooth. 



The paired orifices upon the 13th segment are considered 

 by Michaelsen to represent the rudiments of spermathecse 

 which open into this segment in other Eudrilidse. 



These orifices are fringed with numerous frayed-out cellular 

 processes, which would appear to be of the nature of prolifera- 

 tions of the peritoneum. 



The efi'ect of these must be analogous to the twigs of a 

 lobster-trap ; they would prevent egress from the interior of 

 the segment, but would permit the penis to be thrust in. It 

 seems most likely that these orifices are used in copulation j 

 the sperm can then readily find its way into the interior of the 

 egg-sacs ; and as a matter of fact I can fully confirm 

 Michaelsen's statement that bundles of spermatozoa are found 

 in the interior of these sacs. 



The large sacs which extend from the 14th to the 17th seg- 

 ment seem to me to be in all probability equivalent to the 

 coelomic sacs which I have just described in Hyperiodrilus 

 as encircling the oesophagus and fusing above it to form a 

 large unpaired sac. I consider that Michaelsen is quite right 

 in deciding that they do not represent a portion of the two 

 spermathecEe cut ofi" from the duct leading to the exterior; 

 but, on the other hand, I regard my own identification 

 of these openings as a little more probable than that of 

 Michaelsen. 



The relationship of the egg-sacs to the coelomic sacs in this 

 genus and in Hyperiodrilus is something like that of the 

 sperm-sacs in Dichogaster and other worms to certain sacs 

 connected with the testes and the funnels of the vasa deferentia. 

 It is, perhaps, worth remarking that the connection of these 

 sacs above the intestine is curiously paralleled by the connection 

 of the ovarian sacs in Hyperiodrilus. Next^ with regard to 



