Vndaria and its Species. 



By 

 Kiiitaro Okanmra. 



With PL XI. 



There are three species among our alga which are closefy 

 related to each other, namely ; Vndaria pinnatifida Sur., 

 Hirome undarioides Yendo and Laminaria Peterseniana Kjellm. 



1). The genus Vndaria has been established by Suringar 

 based on Vndaria pinnati£da, which has hitherto been consider- 

 ed as the unique species. The generic character of Vndaria 

 runs as follows : 



" Radix fibrosa ; stipes alatus, alis demum latissimis, un- 

 dulato-plicatis, soriferis ; lamina cryptostomatibus praedita, 

 costata, pinnatim ramosa; sorus in alis stipitis dilatati expans- 

 us, sporangia unilocularia elongato-ellipsoidea vel subclavasform- 

 ia inter paraphyses lineari-elavaeformes unicellularis dense 

 stipatas fovens." — Suringar Illustr. Alg. du Japan, 18 73, p. 77. 



The chief characters specifying Vndaria pinnatMda in the 

 typical form are seen in pinnately divided midribed lamina 

 and large soriferous undulato-plicated wing on both sides of the 

 stem. The dentate ligules at the transition part are indications 

 of the younger stage of pinnate lobes and when the lamina 

 takes normal pinnate form the dentate ligules are always pre- 

 sent. But the cases are never rare where not-pinnateW-lobed 

 but ovate or roundish fronds occur at the same place where the 

 normal forms abound. In such forms the dentate ligules do not 

 make their appearance, and their presence, therefore, is not so 

 essential a feature as is said to characterise this species. 



In the next place, undulato-folded sporophylls on both sides 

 of the stem seem to be very characteristic to this species. There 

 are two forms in this species, northern and southern. The 



