SEA-FISHERIES LABORATORY. 145 



obliquely forward to pass into the midst of the follicles 

 of the shell gland. It is difficult to trace in section, but 

 can be seen to open into the ootype as the latter passes 

 through the shell-gland. 



The excretory system cannot be traced in sections. 

 There is one main vessel which opens to the surface at the 

 very posterior tip of the body. It is elongated dorso- 

 ventrally. It can easily be traced in section as far 

 forward as the testes, and here it is lost. Doubtless it 

 breaks up in the characteristic manner into a multitude 

 of smaller vessels, but I could see no indication of the 

 usual two lateral excretory vessels uniting in the region 

 of the oral sucker. But it is always much easier to trace 

 the excretory system in the living worm, and I had no 

 opportunity of examining such specimens. 



Plate III. 



Allocreadium labracis (Dujardin). 



Reconstructed from a series of transverse sections. 

 Magnified about 18 diameters. 



