394 E. S. GOODEICH. 



The whole nephridium is covered with coelomic epithelium. I 

 have not attempted to follow out the complicated coils of the 

 nephridial tube in series of sections ; but fig. 8, PI. XXXIV, 

 is a diagram showing the main features of the system greatly 

 simplified. Tlie nephridial canal may, for convenience' sake, 

 in description be divided into four regions ; it will be under- 

 stood that the transition in structure between the regions 

 is gradual. The ventral tegumentary vessel (fig. 1, vent, 

 teg. V.) sends branches over the nephridium. The small 

 nephrostorae is attached to the lower edge of the septum 

 (figs. 1, 2, neph. fun.; fig. 9 a), which is in this region free 

 from the ventral longitudinal muscle. Cunningham (4) was 

 unable to ascertain definitely whether it opens into the seg- 

 ment in front of that containing the main body of the ne- 

 phridium and the external pore; while Cosmovici (3) says, 

 *'Pour moi, chaque paire d'organes segmentaires n'est en 

 communication qu'avec Tanneau qui la contient.^^ Claparede, 

 on the other hand, figured the funnel opening into the next 

 segment (2, pi. vi, fig. 5) ; horizontal and sagittal sections 

 clearly show that he was right. Frequently, however, being 

 only suspended to the border of the septum, the nephrostorae 

 seems to swing round and open into the segment which con- 

 tains the nephridium ; but this is not its normal position. In 

 its general structure it is very similar to the nephrostorae of 

 Alitta virens (4); it has, however, a nearly straight margin 

 to its internal opening, and possesses no trace of an internal 

 septum, as described by Cunningham in the above species. In 

 N. diversicolor the edge or lip of the funnel is closely folded 

 back over the outside of the organ (fig. 4, lip of fun.; fig. 

 9, dors, lip, vent, lip), and from this reflected surface and 

 the margin of the internal opening (fig. 9, int. op.) spring 

 long delicate processes (fig. 9, cil. proc), just as in A. 

 virens. These processes contain no nuclei, are formed 

 of very granular protoplasm covered with long waving cilia, 

 and must be regarded as mere outgrowths from the 

 underlying cells. Occasionally the processes branch (fig. 

 3). In the nephrostorae of Nereilepas fucata (fig. 9 a) 



