IÓ4 



[. IJIMA AND ï. KABUKAKI. 



passing into front margin of moderately long, obtusely pointed tentacles. 

 Head flat, not marked off by a neck-like narrowing of body. Trunk 



slender, only weakly convex above, 



1 fi 17 



nearly uniformly broad in the 

 greater part of its length ; hind 

 end obtusely pointed, sometimes 

 rounded. 



Length of large specimens in 

 the creeping state may reach 22 

 mm. in length and 4 mm. in breadth 

 at pharynx region ; usually smaller. 

 Ratio of breadth to length I : 8-10. 



Color on dorsal side usually 

 blackish or dark olive-brown, es- 

 pecially dark in dorsal median parts. 

 Small individuals, in which the pig- 

 ments are not densely developed, 

 may reveal the guts more or less 

 distinctly in various colors. Ventral 

 surface much paler than dorsal 

 surface. 



Eyes two, reniform, each in a half-moon-shaped colorless spot. Dis- 

 tance between them equal to about one-fourth their distance from frontal 

 margin, and somewhat less than the distance of either eye from lateral 

 margin of the same side. 



Mouth opening situated at about the commencement of the posterior 

 third of body. Pharynx inserted a short distance in front of the middle of 

 body. Anterior gut trunk with 4-6 pairs of branches ; posterior gut trunk 

 with usually 12-14 lateral branches and about as many inwardly directed, 

 very short branches. 



Genital aperture behind mouth at a distance equal to about one-third 

 that between mouth and posterior body-end. Testes numerous, about 60 



16. Planaria vìvida, n. sp. in the creepin 

 state. 4X. 



17. Same. Diagram of sexual organs. 

 Index letters as in woodcuts 2, 4 and 8. 



