726 EDWIN S. GOODRICH. 



a genital duct at all, no longer acquiring an opening to the 

 exterior, and in some cases dwindle away perhaps entirely. 

 On the other hand, that it may in various ways become 

 grafted on to the nephridium, and fulfil its primitive function 

 with the help of that organ. 



Quite briefly the facts are as follows : — In the Phyllodo- 

 cidge the nephridium has no internal opening, but in most 

 segments a ciliated genital funnel, developed from the 

 coelomic epithelium, at sexual maturity fuses with and opens 

 into the nephridial duct. The compound organ thus formed 

 functions as a genital duct (Fig. B). In the Glyceridse, in 

 some species (Goniada), the relations of the two organs is 

 found to be exactly the same as that desci'ibed in the Phyllo- 

 docidee (Fig. B). But in others (Glycera), the genital funnel 

 is not known to actually open into the nephridial canal ; on 

 the other hand, it is known to accumulate waste products 

 near the nephridium, to develop early, and to persist in the 

 immature individuals, being active throughout life. The 

 method of exit of the genital products is still unknown. 



In the Nephthyidee the nephridium is also closed 

 internally. The genital funnel is not known to acquire an 

 opening either directly to the exterior, or indirectly through 

 the nephridial canal. The mode of exit of the ova and 

 spermatozoa is not yet known. The flattened genital funnel 

 is persistent throughout life, serving to collect waste products 

 in the neighbourhood of the nephridium (Fig. C) . 



In the Ly CO ride a, or Nereid as, the genital funnel, 

 although larger than in Nephthys, has not been observed to 

 acquire an external pore (Fig. F) . It is quite independent of 

 the nephridium, which has a real open nephrostome of its 

 own (8). 



The Capitellidae have nephridia with true nephrostomes. 

 The genital funnel in some forms (Dasybranchuscaducus) 

 is quite independent, acquires at maturity a pore to the 

 exterior, and functions exclusively as a genital duct (Fig. D). 

 In others the edge of the lip of the genital funnel may 

 become connected with the nephrostome (Dasybranchus 



