Description of Some Japanese Polyclad Tutbellaria« 45 



26. Prost hiostotmun Tubropunctatinn^ n. sp. 



(PI. II., fig. 9.— Textfig. 48). 



This new species is founded again on a single specimen, which 

 was collected between the tide-marks at Misaki. 



Body elongate, narrow, broadly rounded at the head end, 

 pointed at the posterior end. Length 15 mm. ; breadth 2,5 mm. 



Dorsal surface bufty in ground colour, minutely dotted all 

 over with reddish brown pigments; a dark median line extending 

 posteriorly from cerebral ej^e-spots. 



Cerebral eye-spots in two dense groups of an oblong outline at 



about the hind border of the first seventh of body; each group 



4g surrounded by an oval colourless space, the 



two spaces converging anteriorly and uniting 



in the anterior parts. Besides, there exist 



numerous marginal eye-spots arranged in 



two or three rows in the semicircular sub- 



I marginal tract in front of the cerebral eyes 



Textfig. 48. Eye-spots of /- , fi iq >, 

 Prosthiostomumrubro- ^le-ving. <±oj. 



punc.tatum. End-organs of genital systems essentially 



similar to those of ProstJtiostomum siphunadus, etc. It also seems 

 to be nearly related to P. obscurum Stimpsox from Hong-Kong, 

 though differing in the arrangement of eye-spots. 



