12 



Art. 9.— M. Yeri and T. Kaburaki 





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•Mi. 





Textfig. 9. Eye-spots of Nolopîana 

 humilis. 



situated at a distance of about 4 mm. 

 from the anterior margin. Tentacular 

 eye-spots in a crowded cluster at base of 

 each tentacle ; cerebral eye-spots scattered 



&% *•* Jlv •'"■©» över tne brain re gi° n on both sides of 



the median line (textfig. 9). 



Mouth situated slightly in front of 

 the centre of body. Pharyngeal chamber 

 with some lobed diverticula. Main gut 

 provided with numerous lateral branches, which subdivide but do 

 not anastomose. 



The seminal canals (textfig. 10, se), running on either side of 

 the pharynx, converge in front of the male genital opening and 

 unite into an unpaired common canal, the ejaculatory duct. This 

 makes a forward and upward bend and becomes continuous with 

 the tubular seminal vesicle (sv) provided with muscular wall. The 



vesicle gradually narrows 

 in its arched upward and 

 backward course, and 

 finally inserts itself into 

 the pear-shaped prostate 

 at the base. As is 

 general in all species of 

 the genus, the prostate 

 (pr) consists of a number 

 of saccular chambers 

 arranged around the 

 outer end of the ejaculatory duct and opening into this at the base 

 of the small and rudimentary penial projection. The chambers 

 number about six in the present species. The penis is without 

 any trace of stylets. The antrum musculinum is nearly cylindrical 

 and opens externally at its lower end, a short distance behind the 

 pharyngeal chamber. 



The female aperture leads through the ciliated antrum into 

 the shell-gland passage (sgp) which ascends vertically upward. The 

 passage then bends backward, becoming gradually narrower at the 



sc su ^ am ij> im av 



Textfig. 10. Semkliagraiiimatic representation of the 

 genital end-organs of X. liumilix in longitudinal 

 section. 



a v accessory vesicle of vagina. 



other letters as in textfigs. 4 and 7. 



