Description of Some Japanese Polyclad Turbellaria. ]<J 



The uteri (u), after running along the sides of the pharyngeal 

 pocket, extend further backward and join together into a short 

 common uterine duct (uu), which joins the median egg-canal (cc) 

 at its posterior end. The accessory vesicle (av) is exceedingly 

 small and rudimentary. The egg-canal pursues a somewhat 

 tortuous course obliquely forward and upward for a short distance, 

 and then making a sharp downward bend, expands into the 

 vaginal canal (sgp) surrounded by numerous shell glands (sy). 

 The vaginal canal opens to the exterior at a position closely behind 

 the male aperture. 



The present interesting species seems to be somewhat related 

 to Disparoplana dubia Laidlaw (1903 c), but stands distinctly at 

 variance from this chiefly in the ventral position of the prostate, 

 not to speak of minor points of differences. It seems to us that 

 the differences are of sufficient value to separate the two forms 

 generieally. 



Genus Platiocera De Blainville 1828. 



». Planoeera reticulata (Stimpson). 



(PI. I., fig. 4.— Textfigs. 20-22). 



Siidochus reticulatus, Stimpson 1855, p. 381. — Diesinu 1862, p. 569. 

 Stylochoplana reticulata, Stimpson 1857, pp. 4. 11. 

 Planocera reticulata, Lang 1884, pp. 445. 



The species which we identify with Stimpson s Styhchus 

 reticulatus, described by that author from the Loo-choo Islands, is 

 exceedingly common in the neighbourhood of Misaki. It can be 

 •collected there in abundance from the underside of loose stones or 

 pieces of rock between the tide-marks. 



Body broadly oval, leaf-like but rather thick and of a moder- 

 ately firm texture, reaching about 80 mm. in length and 45 mm. 

 in breadth. One of the smallest individuals with developed 

 genital end-organs measured only 10 mm. long by 6 mm. broad. 



General colour of body subject to considerable variation 

 according to both age and individuals. The body grows intrans- 

 parent as the body increases in size and thickness. Usually the 

 -dorsal surface appears more or less dark on account of blackish 



