722 EDWIN S. GOODRICH. 



are placed in paii's, and the cell-bodies are fixed to the sur- 

 face of the nephridium. 



PoLYGOEDiiD^ (Part III, p. 715). 



The nephridium of the adult Polygordius neapoli- 

 tanus is in the form of a narrow tube running just below the 

 junction of the oblique with the longitudinal muscles. Be- 

 hind it bends iowards the epidermis to open to the exterior ; 

 in front it opens into t'he next segment by means of a small 

 nephrostome, one lip of whicH only is ciliated. 



There appears to be no definite trace of a genital funnel, 

 the genital products escaping by rupturO of the body-wall. 



The first nephridium, the so-called head-kidney, of the 

 trochosphere larva (described from an unknown species found 

 on the coast of Ceylon) has a branched internal end, each 

 blind branch of which is provided with a bunch of solenocyte 

 tubes surrounding a single nucleus. 



Hesionid^ (Part I, p. 185, and Part III, p. 713). 



Hesione (Fallacia) sicula has a nephridium which 

 opens veutrally to the exterior, passes inwards and forwards, 

 becomes considerably coiled, and finally ends just in front of 

 the intersegmental region by a small simple funnel opening 

 into the coelom of the next segment. Connected with the 

 lip of the nephrostome by a narrow strip of epithelium is a 

 large crescentic genital funnel (ciliated organ), the ciliated 

 surface of which is marked by deep grooves. Those of the 

 middle region converge towards the lower extremity of the 

 organ, where it is connected with the nephrostome and with 

 the body-wall. The exact mode of exit of the genital pro- 

 ducts is unknown. 



In Tyrrhena the nephridium is essentially the same ; but 

 the genital funnel is smaller and more closely connected with 

 the nephrostome. 



In Kefersteinia and Ophiodromus it completely surrounds 

 the inner extremity of the nephridium. 



Finally in Irma, where the nephridium is no longer coiled. 



