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PACIFIC SCIENCE, VoL XXII, January 1968 
commonly branched in var. scopulorum and blasts are mostly larger and coarser in var. scop- 
arise at more frequent intervals (commonly 2-3 ulorum. Further observations are needed to 
segments) from the prostrate branches. Tricho- determine whether or not the paired arrange- 
Fig. 6. A, Polysiphonia subtilissima var. abbottae, whorl of rhizoids on erect branch. B, Polysiphonia 
tenuis, apex of erect branch. C, Polysiphonia tenuis, cystocarp. D, Polysiphonia upolensis, branch apex. 
E, Polysiphonia upolensis, branch apex with spermatangial stichidia. F, Polysiphonia scopulorum var. scopu- 
lorum, branch apex with paired spermatangial stichidia. G, Polysiphonia scopulorum var. minima, branch apex 
with spermatangial stichidia. 
