I2S 



fg ;j- 3 y lx f- * 5? r j ? @ BK -t ^ * /, ^ 2 . 15 : {^ 14 

 ffi V 2 ;x^ ? * ? r\, ip. 



CompSOpOgOll Oishii Okam. sp. nov. 



Norn. Jap, : Oiski-so. 

 PL. CXXX1I-CXXXIII, Fig. 1-13. 



Diagn. Fronds csespitose, filiform, 1-1.5 mm - thick, elongated, 

 rather harsh to touch and fragile, of dark greenish blue-violet colour, 

 laterally branched, capillary-fine in young branches, becoming 

 unequally thick in older portions, with globular or depresso-globular 

 central cells in fully grown portion, with articulations not exter- 

 nally constricted, thinly corticated (2-cell-layers thick), afterward 

 becoming hollow by the decaying off of the axial cells when the 

 branches attain the thickness of some 400 p in diameter. 



Hah. : On the leaf and stem of Valisneria spiralis, gravels, 

 woods etc. in a brook running from spring (temp, of water 1 5- 

 I7c) Yanokuchi (Prov. Musashi) ; Riv. Tsuchi-kuro (Nagasaki 

 Pref.). 



Descrip. : Fronds densely tufted, filiform, about. 1-1.5 mrn - 

 thick in the lower portion of a thickened frond, elongated, often 

 30 cm. long, usually crooked and somewhat entangled at the lower 

 portion. Plants have a more or less traceable main segment and 

 2-3 times branch laterally in an alternate manner; younger bran- 

 ches are capillary-fine and those standing at the lower portion of 

 frond become somewhat thickened like the main segments. Young 



