— 184 — 



tenuated towards both ends, not stipitate. unequally dichotomous, sub- 

 articulatedly constricted, rooting and proliferating new similar leaves from 

 constricted parts, also proliferating^ laterally from both sides of basal por- 

 tion of segments, thus assuming fascicular disposition of segments." — 

 Ok am. Alg. from Ogasaw. - 



Hab. : On piles, twigs, stones etc. at river mouth. Ogasawarajima 

 (R. Yatabe, Matsumoto), Prov. Tosa, River Ko-yahagi in Prov. Mikawa, 

 Atsuta in Prov. Owari, River Sumida, River Yedo, Tokyo. River Tone, 

 Isohara in Prov. Hitachi. 



De scrip. "Segments are very narrow, linear-lanceolate, 500-900 ft 

 broad, 3-5 mm. long, almost even or slightly undulated at margin, twisted^ 

 gradually attenuating towards both ends, more narrowly towards the base, 

 and not petiolated, more or less provided with the continuation of the 

 wing. The mode of ramification is dichotomous ； but two arms of the 

 Qichotomy are not equal in length and size, one being always shorter and 

 narrower than the other ； often one arm is entirely suppressed. Pro- 

 liferations from the mid-rib are observed neither in the membranous nor 

 in the constricted parts. In the constricted parts, new leaves similar in 

 shape to the segments are proliferated from both siaes, and also from 

 both margins oi the basal portion of segments ； they rise near to each 

 other on one side and even as many as three are proliferated along one 

 side. Proliferated leaves again proliferate other ones from similar places. 

 Thus the sediments seem to the naked eye to arise fasciculately from the 

 constriction. The prohrerated ！ eaves are not at first united to the main 

 segments by a distinct continuation of the mid-rib, as in the continuation 

 of the main segments ； but a little afterwards some of the cells 

 of the membranous portion of segments become a little larger and 

 larger than other cells and they form the continuation of the mid-rib. 



