44 Art. 9.— M. Yeri and T. Kabnraki : 



but characteristic to the present species is the presence of two 

 moderately large and ovoid prostates (textfig. 46. pr), situated 

 closely in front of the seminal vesicle {sv) on either side and open- 

 ing into it at base of penis. Penis (p) small, styliform. and 

 hanging in the tubular antrum musculinum {am), which opens 

 •externally closely behind the pharyngeal chamber. 



25. JProsthioHtotHuiÊi awaense^ n. sp. 

 (PI. II., fig. 12.— Text g. 47). 



This species is based on a single specimen obtained on the 

 •coast of Shirahama in Prov. Awa. 



Body closely similar in shape to the preceding species, being 

 slender, anteriorly rounded and posteriorly tapering to a point. 

 22 mm. long, 5 mm. broad. 



Dorsal surface of a rather deep buffy colour, with a brownish 

 longitudinal band in the median line. Ventral surface much 

 paler, exhibiting slender seminal canals and uteri in a whitish 

 colour. 



Cerebral eye-spots crowded in two oblong clusters, each com- 

 prising about 28 of them. Marginal eye-spots 

 confined to the frontal margin in front of 

 the cerebral groups, forming an irregular 

 row two or three deep. Besides, a few eye- 

 spots scattered closely in front, of the cerebral 

 groups (textfig. 47). 

 Textfig-. 47. Ey(!-3pots of Sucker, mouth and genital apertures 



Prosthiostomum aivaense. . . . . 



situated as in the preceding species. Mam 

 gut extends to near the posterior end of body, giving rise to 

 numerous lateral intestinal branches en both sides. Internal 

 genital organs as in other Prosthiostomum species in all essential 

 points. 



The species seems to be especially closely allied to Prosthio- 

 stomum siphuneukis 1 >. Cm, P. pallidum Laidlaw and P. lineatum 

 Mejxneu, but may be distinguished from any of them by the 

 different arrangement of eye-spots. 



