248 J. T. CUNNINGHAM. 



rated. The efferent duct of the nephridium is therefore not 

 confined in a narrow space between the edges of the dorsal and 

 ventral muscle-bands, as is usually the case, and there is no 

 apparent reason why the duct should not pass between the 

 ventral muscle and the neuropodial bristles as it does in most 

 Polychseta. 



It is certain that in this species the nephridia act as sexual 

 ducts in both sexes. I have frequently seen these organs in 

 the male distended with spermatozoa, and the ova doubtless 

 pass out in the same way. 



Nerine coniocephala, Johnston. 



In this species the nephridia have the same character and 

 somewhat similar relations to those described in the preceding, 

 but the efferent duct is by no means so long, and the external 

 aperture is therefore more ventral in position; it is on the 

 same level as the upper neuropodial bristles, and lies in front 

 of the rieuropodium in the constriction between adjacent 

 somites (fig. 9). Sections of ripe males show the lumen of the 

 nephridium full of spermatozoa. 



Lanice conchilega, Malmgren. 



Several accounts of the nephridia of Terebella conchi- 

 lega have been given. H. Milne-Edwards (' Ann. d. Sci. Nat. 

 (2) Zoologie, x/ 1838, p. 220), in a paper published in 1838, on 

 the circulation in Annelids, describes the vascular system in a 

 species to which he gives this name, and gives a figure of the 

 animal opened along the dorsal median line. In this figure 

 four looped nephridia are distinctly shown, situated behind the 

 branchial region. The representation of the position and cha- 

 racter of these organs is perfectly correct, so far as it goes ; 

 they are the upper parts of the four nephridia belonging to 

 somites vi — ix. But the paper I refer to does not describe the 

 nephridia, as it deals with another subject : they are shown in 

 the figure, and that is all ; and in the description of the figure 

 the organs are referred to as organs of generation. 



