of the posterior suckers. 



19Ö S. GOTO. 



pm median piece 



ppa paired anterior piece 



ppp „ posterior ,, , 



pp process of the posterior piece j 



sa anterior sucker. 



sp posterior sucker. 



sg sticky gland. 



shg shell gland. 



t testis. 



ut uterus. 



vd vas deferens. 



vh vitelline body. 



yd yolk-duct. 



All the figures, if not otherwise stated, were drawn with cam. 

 lue, Zeiss Ex 2. 



PI. XXI. 



Fig. 1. — Dipl. nipponiciuu killed with boiling sublimate; free-hand, 

 surface view, x about 14. The black dots represent the digestive 

 cells seen throuo'h the tissues. 



Fig. 2. — The same, free-hand, from a specimen killed under the 

 cover-glass, shewing the internal organs, half-diagramatic. The 

 right antérieur half [)resents the ventral, and the corresptjnding 

 posterior half the dorsal aspect ; and vice versa with the other 

 individual. The nerves are colored yellow ; the excretory ves- 

 sels indigo- blue. 



Fig. 3. — Chiti nous frame- work of the posterior sucker as seen in a 

 specimen under the cover-glass. 



Fig. 4. — Section of the postericn' sucker in the direction indicated by 

 ab in Fig. 3. 



