INTERNAL ANATOMY. 



-e.o 



;6.0 



In the posterior chamber there are four pairs of much 

 larger nephridia, which are similarly joined together by a 

 prominent longitudinal duct from which short processes 

 corresponding in number to the nephridia lead to the 

 external apertures. The 

 duct itself ends blindly at 

 both ends, but is prolonged 

 posteriorly far beyond the 

 region of the nephridia 

 (Fig. 40). 



The presence of this 

 longitudinal duct in these 

 worms is a very remark- 

 able circumstance, but it is 

 undoubtedly an expression 

 of the same phenomenon as 

 the anastomoses between 

 successive nephridia which 

 have been described by 

 EISIG for the Capitellidae, 

 as well as the complicated 



Series of anastomoses which Fig. 40. Schematic lateral view of 



. anterior end of Lattice conchilega to show 

 Convert the entire nephn- the nephridia. (After EDUARD MEYFR 



dial system into a marvel- fro Hatsche k's LehMj derZooio^ 



J The ventral side of the body is to the 



loilS network Of tubules dis- left of th e figure, d. Longitudinal ducts of 



11 A C* T3 *^ e ne Ph r 'dia. e.o. Position of external 



Covered by A. (j. -BOURNE openings. / Nephridial funnel ( = coalomic 



in the marine leech Pon- P enin s of nephridium). /. Position of 



mouth ; bounded by two prominent lateral 

 tobdella, and by BEDDARD lobes, and fringed by a great number of 



" feelers," which are cut short in the figure, 

 in the CUriOUS earthworm, ,. Branchial tentacles (three on each side 



Perichceta. of the body). 



The present state of our knowledge does not admit of 

 an attempt to specify the particular type of nephridial 

 system from which that of the Annelids, on the one hand, 



