86. 



In Nucula proxima there is a strand of tissue passing 



from eacli otocj^st to the surface of the foot. This corresponds 



(15) 

 in position to the canal described by Polseneer for Nucula 



mus/culxis, and is probably an open canal, but I have not had tine 



to demonstrate this point. 



In Yoldia limatula, the strand of tissue, with the 

 series of pouches which it sorae times encloses, seems to indicate 

 that these canals have undergone^ and perhaps are still undergoing 

 degeneration. 



The otocystic nerves lie alongside the canals and seem 

 to send fibers to their walls. In fact it is difficult to demon- 

 strate that the ner^res reach the otocj'-sts other tlian through, the 

 walls of the canals. 



OSPHRADIUM. 



On the inner side of each suspens or;;'- membrane of the 

 gills, lying just beneath the visceral ganglion of the corres- 

 ponding side, is a rather large patch of modified epithelium 

 which probably represents an osphradixtm. 



This epithelium is s^applied hj a rather large nerve, 

 figure 4, on, that leaves the corresponding visceral ganglion 

 protty well forward * (h*^^-^ "-^ ^:x^..^^^^<^^ ^^.-^ . 



