122 PACIFIC SCIENCE, Vol. IV, April, 1950 
Fig. 3. Antithamnion cristirhizophorum Tokida and Inaba, sp. nov.: a, part of the lower portion of 
a frond, showing rhizoidal filaments, gland cells, and a young branch; b, the same, showing a tuft of 
rhizoidal filaments attached to a branch of Ceramium sp.; c, a pinna bearing nine pinnulae, two of 
which are once-divided pseudo-dichotomously near the tip; d, the tips of three ultimate ramuli. a and 
c, X 137; b, X 150; d, X 480. 
usually simple, but rarely pseudo-dichoto- 
mously divided at their apices. 
Platythamnion horridum Tokida and Inaba, 
sp. nov. 
Figs. 3 a, b\ 6a-d\ la-d 
Fronde usque ad 2 cm. alta, subdichotome 
repetite ramosa, pinnis quaternis dense ver- 
ticillata; pinnis lateralibus maturis brevissi- 
mis, 80-200 g longis, ad basin 22-46 g cras- 
sis, axibus 5-7-cellularibus, oblanceolatis, su- 
periore latere pectinatis, in inferiore parte 
binis seriebus pinnularum ramosorum orna- 
tis, cellulis basalibus inferiore latere nonnum- 
