NEW GENERA AND SPECIES OF EAETHWORMS. 247 



tine a solid-looking white body, which is simply a dilatation 

 of the sperm-duct filled with sperm ; the opaque white colour 

 is of course due to the contained sperm. The funnel which is 

 connected with one end of this dilated region was evident in 

 one specimen; it lies within the sperm-sacs. These latter 

 commence at the septum dividing Segments 10 and 11 as a 

 narrow tube placed below the intestine, and enclosing the 

 ventral blood-vessel. The two hearts of this segment join the 

 ventral blood-vessel within the sac, as is shown in the figure 

 (fig. 8). A very short way back the sperm-sac divides into 

 two narrow tubes, each of which runs close to the dilated 

 extremity of the sperm- duct, and appears to be connected 

 with it. Behind the septum the two sperm-sacs, which have 

 still the character of very narrow tubes, gradually approxi- 

 mate and pass back in close continuity to each other, and to 

 the dorsal wall of the intestine. In another example the 

 sperm-sacs commenced at the septum, just behind the oval 

 dilatation of the sperm-duct already referred to. In this 

 worm the funnel of the vas deferens was quite visible ; it lies 

 just within the beginning of the sperm-sac, but in the 11th 

 segment ; the orifice of the funnels is directed backwards, as 

 is so often the case with the Eudrilidse. The sperm-sacs in 

 this individual were of unusually great length ; they passed 

 back to as far as the 60th segment. The sperm-sacs are 

 divided into two regions : the anterior part, as far as about 

 the 30th segment, consists of a narrow tube which lies 

 perfectly free in the body-cavity; it is not attached to the 

 intersegmental septa, which are largely defective dorsally; 

 when the body is opened the sperm-sacs require no dissection 

 to set them free. The posterior section of these tubes has a 

 difi'erent structure; the walls become thicker and sacculate, 

 being constricted at the septa; in one specimen the two sacs 

 were united at the distal extremity; in another the sacs 

 remained independent, though closely approximated. The 

 length of the sperm-sacs was 65 mm. in one worm ; they were 

 longer in another. They appear to be more extensively 

 developed than in P. coeruleus; and Dr. Michaelsen says 



