32 Art. 9.— M. Yeri and T. Kaburaki : 



15. Callioplana marginata Stimpson. 



(PL I., fig 1— Textfigs. 35-87). 



Callioplana marginata, Stimpson 1857, pp. 4, 11. 



Stylochus marginatus, Diesing 1862, p. 569. — Meixneb, 1907, p. 108. 



Planocera (?) marginata, Lang 1884, p. 445. 



A large number of specimen referable .to this species were 

 collected between the tide-marks at both Misaki and Sunosaki. 



Body oval with frilled margin, leaf-like though somewhat 

 elevated in the dorsal median parts. Large individuals may reach 

 50 mm. in length and 30 mm. in breadth, while one of the smallest 

 measured only 15 mm. long by 7 mm. broad. 



Colour of dorsal surface velvety black, bordered all around with 

 a narrow band of tawny brown just inside the colourless margin. 

 Ventral surface much paler than the dorsal, and revealing pharynx 

 and reproductive system to a certain degree in a whitish colour. 



Nuchal tentacles conical, orange-coloured in the distal and 

 colourless in the basal parts; each situated on a clear spot about 

 the hind border of the first fifth of body. 



Tentacular eye-spots forming a 

 group in the basal parts of each 

 tentacle; cerebral eye-spots dis- 

 tributed in an elongate tract on each 

 side (textfig. 35). 



Mouth situated nearly in the 

 centre of body. Pharyngeal sheath 

 Textfig. 35. Eye-spots of Caiihpiana provided with numerous lobed diver- 



marginata. . ■,. . , 



ticula corresponding m a general 

 way to the folds of pharynx. Main gut produced into about 7 

 pairs of la cral intestinal branches, the final branchlets of which 

 but rarely anastomose. 



Tesle..- ventrally situated. Seminal canals (textfig. 30, sc) 

 form a V-like loop closely behind the female genital opening; 

 anteriorly at the anterior border of the second quarter of body the 

 two limbs of the loop bend sharply inward and backward, forming 

 inner limbs which run parallel to the outer and converge in front 

 of the penis to join the slightly distended and non-muscular seminal 



