220 PACIFIC SCIENCE, Vol. XVIII, April 1964 
Fig. 6. A—C, Polysiphonia yonakuniensis Segi. D-G, Polysiphonia subtilissima Mont. A, A vegetative 
branch. B , Apex of a branch with a trichoblast. C, Basal segment of a thallus showing rhizoids with branched- 
segmented tips. D, E, Branches showing trichoblasts. F, Segment of a basal thallus showing a rhizoid with 
digitate tip. G, Basal segment of a thallus showing a simple rhizoid. 
