42 



Art. 2.— T. KaUuraki : 



and limited in tlieir distribution to between tlie ovaries and the 

 pharynx-insertion. It is of an irregularly oval or spheiical shape 

 and is made up of sperm-niother-cells and spermatozoa in various 

 stages of development, surrounded by the tunica propria. 



The vasa deferentia, after proceeding backwards, as usual, 

 inside the longitudinal nerve cords, in the posterior parts take a 

 forward turn, rising upwards at the same time, before tliey open 

 separatel}^ into the lumen of the penis on the dorsal side. The 

 vas deferens is full of spermatozoa throughout its length. 



Text fig. 13. Sagittal section of sexual organs of Pohj. auriculata, cliagrammatically 

 shown. 



Index letters as in text figs. 2, 5 and 6. 



The Spherical bulbous part of the penis consists of connective 

 tissue with variously directed muscular fibres, and contains a wide 

 cavity, the seminal vesicle, which is piovided with a somewhat 

 folded wall. The cavity passes gradually into the wide ejaculatory 

 duct, opening at the tip of the intromittent part of the penis, which 

 is of a conical shape and is hoi'izontally disposed in the penis- 

 sheath. Embedded in the parenchyma around the penis are 

 present numeiHiUs penis-glands which open into the lumen of this 

 organ. 



