I »(script ion <>f Some Japanese Polyclad Tutbellaria. 



27 



prostate (pr). After this it proceeds further backward, finally to 

 open on the underside of the tip of penis (p). The intromittent 



p Ä part of the penis is 



large, cylindrical in 

 shape and horizontally 

 disposed in the penis 

 sheath. The extreme 

 tip of penis, behind 

 the terminal part of \he 

 ejaculatory duct, con- 

 tains a vertically dis- 

 posed pad of connective 

 tissue. On account 

 of the presence of that 

 peculiar pad, the part 

 of the ejaculatory duct 

 lying in front of it 

 presents, in horizontal 

 sections, a lumen of 

 crescentic outline. The 

 thick wall of penis con- 

 sists of three muscular 

 layers, circular, longi- 

 tudinal and diagonal. 

 Antrum with an annu- 

 lar outbulging. Ex- 

 ternal male aperture 

 on the hind border of 

 the third quarter of 

 body. 



The female aperture, situated a short distance behind the male 

 end-organs, leads into the vagina (v), which runs obliquely foreward 

 and dorsalward for some little distance, and then, after receiving 

 the unpaired unterine duct (mi) from behind, runs backward to join 

 the large elliptical accessory vesicle (av). The vaginal canal is 

 surrounded by shell-glands, especially numerously in the neigh- 



Textfig. 28. Diagrammatic representation of the genital 

 end-organs of P. takeshitai, as seen from the ventral 

 side. 



Textfig. 29. Genital end-organs of P. takeshitai in sagittal 

 section. Semidiagrammatic. 

 Index letters as in textfigs. 4, 7 and 10. 



