20 



Art. 2.— T. Kaburaki 



receives the opening of the penis-sheath from the front. The 

 direct wall of the atrium is an epithelium made up of cuboidal 

 cells, beneath which is, as usual, a muscular coating composed of 

 circular and longitudinal fibres. 



The testes, which are of an iiTegular form, occur in abundance 

 mostly in ventral, but some in dorsal, parts of the body, arranged 

 on both sides of the anterior gut trunk and also outside or inside 

 the posterior gut trunks. 



Text fig. 7. Diagram of sexual organs of PI. painllifera in sagittal section. 

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



The vasa deferentia, after pursuing a sinuous course back- 

 wards along the inner side of the longitudinal nerve cords, bend 

 abruptlj^ inwards at the region of the penis, rising upwards at the 

 same time, finally to open into the seminal vesicle separately on 

 the sides of the penis. 



The jDenis consists, as usual, of the semispherical bulb and 

 the conical intromittent part which is almost horizontally dis- 

 posed in the penis-sheath. The former contains a very wide, 

 smooth-walled lumen, the seminal vesicle, which posteriorly gives 

 rise to the slender ejaculatory duct, opening at the apex of the 

 penis. 



