1922] Setchell-Gardner: Phycological Contributions 387 



of the cells resulting from longitudinal division gives rise to a branch, 

 shorter or longer, but similar to branches arising in the regular 

 manner. The branches are typically secund, but may rarely come from 

 the opposite side of the filament. ]\Iany of the main filaments become 

 much curved in this branching region. 



Streblonema Porphjnrae sp. nov. 



Plate 44, figure 6 



Frondibus plerumque endophyticis ; filamentis prostratis maxime 

 tortuosis, inter parietes cellularum hospitis penetrantibus, copiose 

 ramosis; filamentis erectis ultra superficiem hospitis leviter protrud- 

 entibus, passim ramosis; filamentis piliferis ignotis; cellulis fila- 

 mentorum repentium 3-4|U, diam., forma irregularibus ; zoosporangiis 

 ignotis; gametangiis filamenta erecta terminantibus, ultra superficiem 

 hospitis leviter protrudentibus, forma fusiformibus ad irregularibus, 

 25-35jU, longis, S-S/x latis. 



Growing in the parenchymatous base of Porphyra naiaduni on eel- 

 grass. Pacific Grove, California. Type, Gardner, no. 4686 (Herb. 

 Univ. Calif., no. 207008), December. 



Strehloncma Porphyrae is an exceedingly diminutive, though appar- 

 ently distinct, species, confined, so far as we know at present, to the 

 cushion-like bases of Porphyra naiadum. It ramifies deep into the 

 tissue, apparently not entering the cells. 



Streblonema myrionematoides sp. nov. 



Plate 44, figure 7 



Frondibus microscopicis ; partibus prostratis exiguissime evolvatis, 

 inter srata duo aut tria externa cellularum hospitis leviter penetrant- 

 ibus; filamentis erectis plus minusve ad superficiem hospitis fascieu- 

 lato-ramosis ; 65-80/a longis, plerumque fructuosis. pilis exiguis; cellulis 

 filamentorum penetrantium 4-5/t diam., forma irregularibus; zoo- 

 sporangiis ignotis; gametangiis numerosis, cylindricis, 50-65;U longis, 

 4.5-6.5/x latis ; loculis uniseriatis. 



Growing on the blade of Laniinaria Andersonii. Moss Beach. San 

 Mateo County, California. Type, Gardner, no. 4622 (Herb. Univ. 

 Calif., no. 207005), July. 



It is an extremely perplexing problem to decide upon the generic 

 position of forms such as the one we have named and described above. 

 It has close affinities with the three genera, Streblonema, Ectocarpus, 

 and Myrionema. The erect fronds exterior to the host and more or less 

 branched, with relatively scanty attaching portions, constitute the 



