422 University of California Publications in Botany [Vol.8 



10. Ectocarpus simulans S. and G. 



Fronds 1-2 mm. high, tufted; prostrate filaments irregular, tor- 

 tuous, distinct ; erect filaments simple, tapering slightly upward, not 

 piliferous ; cells cylindrical, not constricted at the dissepiments, ll-lSju 

 diam. in the central part of the filament, 1-2.5 times as long as the 

 diameter; chromatophores band-shaped, nearly covering the cell, few; 

 zoosporangia unknown ; gametangia lateral or occasionally terminal, 

 sessile, narrowly ellipsoidal, blunt, mostly slightly curved, 55-65/i 

 long, 15-20/* wide. 



Growing on Chaetomorpha aerea. Cypress Point, Monterey 

 County, California. 



Setchell and Gardner, Phyc. Cont. VI, 1922, p. 412, pi. 45, figs. 

 9-11. 



The present species resembles, in general, certain forms of Ecto- 

 carpus pusillus Griffiths (cf. Sauvageau, 1895), but the erect filaments 

 are much more slender, usually never branched, and with much 

 smaller gametangia. It forms tufts on Chaetomorpha aerea., whose 

 filaments are encircled by the prostrate filaments of the Ectocarpus 

 which form small cushions in their growth over one another. The 

 gametangia are rather blunt and often more or less curved. 



11. Ectocarpus flagelliferus S. and G. 



Fronds densely tufted, 3-5 mm. high, attached by a few creeping 

 filaments and by small, colorless, descending rhizoidal filaments from 

 the lower cells ; erect filaments simple below, sparingly and alternately 

 branched above, tapering gradually upward and abruptly at the base, 

 piliferous when young; cells of the main filaments slightly doliiform, 

 25-35//, diam., 0.25-1.5 times as long as the diameter ; chromatophores 

 small, irregular bands or plates, without pyrenoids; zoosporangia 

 unknoAvn; gametangia very variable in shape and size, fusiform to 

 cylindrico-conical, mostly lateral on long pedicels, occasionally ter- 

 minal on short, erect filaments, or long seriate-intercalary on the main 

 filaments, the lateral 125-200/* long, 28-40/x, broad, the terminal and 

 intercalary up to 1.5 mm. long. 



Growing on eel grass. Sitka, Alaska. 



Setchell and Gardner, Phyc. Cont. VI, 1922, p. 408, pi. 47, figs. 

 25-27. 



