- 80 



thick. Frond is very variable in shape being oval, elliptical, sublanceo. 

 late or suborbicular etc., rarely undivided, usually more or less irregularly 

 lobed and lacerated, sometimes folded or roughly wrinkled, undulated, and 

 entire or repando-dentate at margin; surface usually perforated by larger 

 or smaller roundish or irregularly shaped foramens which often become 

 confluent. Cells in the lower portion of membrane vertically elongated 

 in long prismatic form, 2-3 times high as broad in cross-section with 

 rather thick outer wall ; in marginar portion cells become shorter and 

 subcubical, being almost equally high as broad or a little surpassing it. 

 When fructified, the margin of frond is transformed into broadly linear 

 rim of olive-yellow coloured sori ; fertile cells are a little higher than 

 adult vegetative cells and open by teat-like pores. Colour when young 

 beautiful yellowish-green, when adult becoming bluish-green and opaque. 

 Substance rather rigid when fresh, and the plant does not adhere to 

 paper in drying. 



Hub. : At first the plant grows on shells, pebbles, rocks, twigs etc. 

 in littoral zone, afterward often becoming free and continues to grow 

 even in that state. Very common along both coasts of this country as 

 far as Kurile Islands. Chosen, Taiwan and Ogasawarajima. Swarmspores : 

 late in spring. 



I was not able to see the conjugation of the two-ciliated swarmspores 

 of this plant in the vicinity of the Tokyo Bay, and the zoospores with 

 four cilia have not yet been observed. 



PI. CLXIX, Fig. 8: fertile frond of Ulva pcrlitsu Kjellm.; x, sori; 

 nat. state and size. 



PI. CLXX : Fig. 1: cross-section of frond of Ulva /tci tnsu Kjellm.; 

 <>ru' cm. above the base. 108," thick; 2 j. Fig. 2-3: cross-section 

 of marginal portion, 50 and 46 . thick respectively; 2: r 'j", 3: 



