i6o 



I. IJIMA AND T. KAIiURAKI. 



Mouth situated at about the posterior end of the middle third of body. 

 Pharynx insertion at about the middle of body. Anterior gut trunk with 

 7-9 pairs of branches ; each posterior gut trunk usually with 13 lateral 

 branches and about as many, but very short, inwardly directed branches. 



Genital aperture nearly in the middle of the posterior third of body. 

 Genital organs essentially as in the preceding species. Atrium an irregular 

 prolonged space with wall thrown into folds ; with an extensive annular 

 space in front of the junction of oviduct. Testes numerous, small, arranged 

 in two lateral longitudinal zones running along lateral body edges, from 

 behind ovaries to close the posterior body-end ; mostly lying ventral to the 

 ends of lateral gut branches. Penis an elongate, muscular-walled, sack-like 

 organ, opening behind into the anterior part of atrium on the floor ; vasa 

 deferentia opening into vesicula seminalis separately and without making a 

 forward turn. Ovaries two, situated behind first (or second ?) pair of gut 

 branches. Oviducts united into a short unpaired duct before opening into 

 the posterior part of genital atrium from above. Receptaculum seminis 

 large, lying between penis and pharyngeal chamber. Vagina slender, 

 traversing behind close under dorsal epidermis, at the end bending forward 

 to join atrium from behind. 



Localities : — Cool running brooks at following places : Yamada and 

 Kanazuchi in Prov. Rikuzen, Koiwai in Prov. Rikuchu and Inawashiro in 

 Prov. Iwashiro. Collected by Ijima 1887 and by Kaburaki 1915. 



6. l'lanaria ffonoephala Dugès. 

 Woodcuts 12 and 13. 

 Head triangular, with lateral auricular processes, the sides forming in 

 front a somewhat rounded median angle of approximately 6o° . The body 

 is broadest at the auricular processes. Trunk slender, with lateral margins 

 even and nearly parallel for a large part of the length, but in the hind 

 parts tapering to the bluntly pointed posterior extremity. 



Commonly 20-33 mm. long and 2^-4 mm. broad in the pharynx 

 region. Ratio of breadth and length 1 : 7-10. 



