8 S. HATAI. 



tions, enters the main mass of the nephridium. This mass is very large, filling up 

 the greater part of the ccelomic cavity ,'and its cells contain numerous granules, pro- 

 bably products of secretion. The canal entiring the mass at the anterior end runs 

 backwards and reaching the posterior end, turns forwards and emerges out of the 

 main mass at the anterior eud clos 2 to where it entered. It then follows its former 

 course closely and again enters t lie main mass, and reaching its posterior end again 

 turns forwards and then turning backwards at the anterior end of the mass finally 

 opens to the exterior. The loop formed by the latter portion of the canal at the 

 posterior end of the mass presents a large ampulla destitute of cilia. The canal is of 

 the same calibre in all its parts except near the nephridiopore, where it slightly en- 

 larges and sends out many diverticula, which are, however, never forked at 

 the extremity. The cilia are present only at definite points, and their amazingly 

 rapid vibration causes a swift current, but the ciliated portions are not enlarged, as in 

 Vermiculus limosus Hatai. The cilia can only with dificulty be observed in the 

 living state, owing to the great contractility of the nephridium. The convoluted 

 portion of the nephridial canal lying outside the main mass is provided with numerous 

 muscular bundles from the body wall, which move it backwards and forwards. 



Gmilal syxtem. 



The male genital organs are the testes, sperm-sacs and sperm-ducts, and the 

 female organs are the ovaries, oviducts, spermathec.v and reccptacula ovorum. The 

 main organs always lie in segments X and XT, agreeably to the generic character. 



Testes. — One pair of testes on the posterior face of septum IX/X, close to the 

 ventral cord. Each consists of loosely agregated globular cells, which are easily 

 separable from each other. The nuclei of the cells are very conspicuous towards the 

 free end. It is pear-shaped when young but palmate when fully ripe. 



Jllale-dad. — One pair of male-ducts lie in segment XL It is very n rrow but 

 long, and undergoes several windings, the degree of the convolution varying, however, 

 according to development. The funnel is very wide and presents a somewhat ur- 

 ceolate form. It is attached to the anterior face of septum X/XI, and is slightly 

 turned towards the median line. The ciliated columnar cells of the funnel are ar- 

 ranged regularly in one layer. The funnel is continued to the long narrow vas 

 deferens, which, after running backward till about the middle portion of segment 

 XII, turns forward and opens to a wide atrium. The atrium is the enlarged portion 

 of the sperm-duct and is spindle shaped, its widest portion being more than three times 



