TWO AQUATIC OLIGOCHiETES. 



17 



motion is very rapid " (Hatai). The funnel is continued into a 

 long narrow canal which immediately pierces the septum. The 

 canal undergoes a few convolutions and becoming smaller pro- 

 ceeds dorsalwards nearly parallel with the septum. At the dorsal 

 end, it again becomes broader, undergoes two or three convolu- 

 tions, and then proceeding ventralward s enters the main mass of 

 the nephridium, in which the canal undergoes convolutions for 

 the third time. After leaving the main mass the canal proceeds 

 to the nephridial pore with a few windings on the way. 



The chief characteristic of these organs is the constant 

 presence of numerous large vesicular peritoneal cells attached 

 around the nephridial canal, imparting a racemose appearance to 

 the whole organ. These cells are club-shaped, and contain a 

 thin cytoplasm. The nuclei are large, nucleolated and always 

 situated at the proximal end of the cells. 



2). Posterior nephridia. The funnel is exactly similar to 

 that of the anterior nephridia. " The funnel is continued to a 

 long narrow canal, which after undergoing manifold convolutions, 

 enters the main mass of the nephridium " (Hatai). According to 





p. mm 



4/" 



X sp 



Fig. 8. 



L. gotoi. Posterior rjephridium from middle part of body ; from a living specimen, x 150. 

 f — funnel, sp — septum, a.mm — anterior main mass, p.mm — posterior main mass, o — external 

 orifice, s— seta. 



