40 



Art. 9.— M. Yeri and T. Kabnraki : 



■12 



At the base of penis this receives the duct of the pyriform prostate 

 (pr), lying just dorsal to the ejaculatory duct. The penis (p) is 



represented by a small 

 horny stylet disposed 

 vertically in the sheath. 

 The antrum musculinum 

 (am) forms an obliquely 

 upwardly directed annular 

 outbulging before it opens 

 externally through the 

 short tubular part. 



i i> Q pr sv 



Textfig. 42. Male genital end-organs of Pseudocer.os 

 nigromarginatus in a cross section. 

 Semidiagramrnatic. 

 Index letters a« in textiles. 4 and 7. 



Family Euryleptidse Lang. 



Genus Cycloporus Lang 1884. 



21. Cyeloportts papillosus (M. Sars). 



(PI. L, tig- 9). 



Two individuals of this form were discovered beneath stones 

 between the tide-marks at Misaki. 



Body oval, moderately firm, 9 mm. long by 6 mm. broad. 

 Dorsal surface of an ochraceous colour, dark in the median longi- 

 tudinal zone, flecked with numerous russet and some darker spots 

 in the place of dorsal papillae which are altogether absent in the 

 Misaki form. Along the body margin a series of dark spots 

 indicating position of the end-vesicles of intestinal branches. 

 Frontal margin produced into two short but distinct marginal 

 tentacles with rounded end. 



Tentacular eye-spots distributed at base of each marginal 

 tentacle. Cerebral eye-spots arranged in two distinct groups over 

 the brain region. 



Mouth situated slightly behind the brain. Main gut extends 

 backward to near the posterior end of body, giving rise to 6 pairs 

 of lateral intestinal branches in its course. The branches distinctly 

 anastomose; the terminal branches open to the exterior by minute 

 pores on the lateral bod}^ margin. Sucker placed slightly in front 

 of the centre of ventral surface. Male and female genital apertures 

 lie between the mouth and the sucker. 



