42 



elliptical sorus, at least at the beginning, as it is seen from those 

 formed in terminal segments. They become gradually confluent 

 and in some irregularly roundish sori are formed, while in the 

 other more or less elongated linear ones are produced. Afterward 

 they become more and more confluent and the whole surface excep 

 marginal portions become equally covered with them. Such seems to 

 be the" case in the fronds having broader branches. In narrower 

 fronds, tetragonida are seen from the beginning to be densely 

 scattered in elongated patches between both margins. 



PL. CXI. Fig. 1: typical form of Dictyota dichotoma (Huds.) 

 Lamour. bearing tetragonidial sori, (from Enoshima) \. Fig. 2 : 

 oosporic frond from Toba in the Prov. Shima, \. Fig. 3 : tetra- 

 gonidial frond of a narrower form (from Hebiura, Prov. Mutsu), \. 

 Fig. 4 : tetragonidial frond of a pinnate form (from Nomo, Prov. 

 Hizen), \. Fig. 5 : cross-section of basal stupeus portion of a 

 frond, j l . Fig. 6 : surface view of frond showing the cells of 

 epidermal and internal layers, -^ . Fig. 7 : portion of a tuft of 

 hairs, " . Fig. 8 : vertical section through oosporic sorus, ^-. 

 Fig. 9 : growing apices of branches, ^-. 



PL. CXII. Fig. 1 : torted and proliferous frond of Dictyota 

 dichotoma (Huds.) Lamour. (from Futaye, Prov. Higo), \. Fig. 2 : 

 torted and slenderer frond (from Prov. Satsuma), }. Fig. 3 : 

 torted and broader frond (from Nomo, Prov. Hizen), }. Fig. 4 : 

 portion of a frond which I took for f. implc.va (from Prov. Higo), 

 . Fig. 5-6 : two forms of branches taken from one and same 

 frond illustrated in the fig. 4 ; \. Fig. 7 : portion of a typical frond 

 bearing proliferous segments from surfaces and margins (from the coast 

 of the Japan Sea), j. Fig, 8 : portion of surface of fronds showing 



