SEA-FISHERIES LABORATORY 



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antero-dorsal surface of the posterior testis, and the other 

 from the dorsal surface of the anterior organ. They run 

 forward, pursuing an undulating course, penetrating 

 between the convolutions of the uterus, and then dorsal 

 to the ventral sucker. At the posterior margin of the 

 latter they join together, entering at once into a capacious 

 seminal vesicle. 



Fig. 3. Allocreaclhim labracis (Dnj.). Diagram of genital ducts. 

 Projection in vertical horizontal plane. 



This latter structure is a wide tube situated dorsally 

 to the ventral sucker. It is either a straight, or slightly 

 bent vessel, as is shewn in fig. 3, or is thrown into two 

 or three loose coils, as is indicated in Plate III, which is a 

 projection in a longitudinal plane of the genital organs, 

 and has been deduced from a series of longitudinal 

 sections. The seminal vesicle is surrounded by a fairly 

 thick fibrous and muscular sheath — the cirrus-sheath. 

 At about the anterior margin of the ventral sucker the 

 seminal vesicle contracts greatly in diameter to form the 

 cirrus. But the cirrus-sheath is still wide, and the space 

 between cirrus and sheath contains the follicles of the 

 prostate gland. The cirrus itself is a narrow, thick- 

 walled tube, and it is quite unarmed. The cirrus-sheath 

 or pouch terminates in the ventral and posterior part of 



