July, 1917.] K. YENBO.— NOTES ON ALGAE NEW TO JAPAX. VII. 197 



and collecting some species of Sargassum which have the so- 

 called " duplicated " leaves, on the western coasts of Kiushu. 

 They were all fertile and complete. One of them fully coincides 

 with S. Sandei Rbld. As the species with this sort of leaves 

 have been but incompletely ob- 

 served, some remarks will not be 

 superfluous to be given here. 



The word " duplicated " ma}' 

 have some significance in the 

 pressed specimens only. In the 

 living plants, the " duplicated " 

 part of a leaf is an expansion of 

 shallow concave form, sitting at 

 right angles upon the top of 

 the perpendicular leaf. The term 

 " turbinarioid " will much better 

 express the natural and true aspect 

 of the leaf. 



The type of this group, S. 

 duplication J. Ac, is also found 

 in the southern seas of Japan. In 

 this species, the leaves on the 

 principal stem (thefulcrant leaves), 

 as well as those on the ascending 

 branches are perpendicularly dis- 

 posed. This disposition of leaves 

 will naturally result to the plant 

 an incomplete facing to the light. 

 The turbinarioid shape of leaves, 

 however, facilitates the plant to 

 receive a larger amount of the 

 light, since the plant grows al- 

 ways upright in a depth of 1-4 

 fathoms at low tide hours. When 

 the plants flourishing in the sub- 

 marine forest of Sargassum are- 

 looked down from the surface of 



Sargassum doplicatura Bory f 'V- 



\|p ill '.- n:it. size. ( 



