254. 



Puget Sound Marine Sta. Pub. 



Vol. 1, No. 25 



1. PYLAIELLA Bory 



1. Pylaiella littoralis (L.) Kjellman^ Bidr. Skand. Ectocarp. p. 99; 



(Ectocarpus littoralis Ag. Sp. p. 40). Fig. 1 



Plants composed of loosely intertwined light brown or olive green 

 filaments 3 to 15 cm. long; branches few or many, opposite or alternate, 

 narrow, several times as long as wide, not tapering, usually standing at 

 right angles to the main filaments. Chromatophores disc-shaped or some- 

 times irregular plates, several in each cell. Plurilocular sporangia inter- 

 calary with the vegetative cells, in series or single ; unilocular sporangia 

 usually in series, on the branches with several vegetative cells on the tip. 



A variable species, represented by two varieties, var. opposita with 

 opposite branches, and var. firma with alternate branches. 



Forming dense brown tufts on piles and rocks near low tide mark. 



Pylaiella 

 littoralis 



Ectocarpus 

 siliculosis 



Ectocarpus 

 confervoides 



PLATE 47 



Fig. 1. a, Portion of a filament with unilocular sporangia; b, pluri- 

 locular sporangium. X about 100. 



Figs. 2 and 3. Portions of filaments with plurilocular sporangia. 

 X about 200. 



2. ECTOCARPUS Lyngbye 



•Plants filamentous, monosiphonous or sometimes partly polysiphonous, 

 branched or rarely unbranched ; attached to substratum or host by creeping 

 or penetrating branching filaments. Tips of branches ending in colorless 

 hairs or all cells of branches containing color ; sporangia external, sessile 

 or stalked, terminal or lateral, not intercalary ; plurilocular sporangia 

 usually ovate or cylindrical, formed by closely aggregated cells ; unilocular 

 sporangia usually oval or globose. 



