1925 J SetchcU-Gardner: Melanophyceae 421 



9. Ectocarpus terminalis Kiietz. 



Fronds 0.75-2 (or 4) mm. high, mostly forming* a continnons 

 velvety layer, brownish in color ; creeping filaments irregular, 

 branched, anastomosing and forming, at times, a partially pseudo- 

 parenchymatons layer; erect filaments simple or sparingly branched, 

 more or less attenuated above; cells of creeping filaments 8-24fi long, 

 10-18ft broad ; cells of erect filaments cylindrical, 8-12/a broad, up to 

 six times as long ; chromatophores short, band-shaped, few in each 

 cell ; zoosporangia terminal, ellipsoidal, 26-52ju, long, 20-30j«, broad ; 

 gametangia ovoid or ovoid-oblong, often curved, terminal, or lateral 

 and sessile or short-stalked, 48-120ju, long, 16-32/x broad. 



On larger Melanophyceae. Alaska (Unalaska) to southern Cali- 

 fornia (Laguna). 



Kuetzing, Phyc. Germ., 1845, p. 236, Tab. Phyc, vol. 5, 1855, pi. 

 74, fig. Ill; Kjellman, Skand. Ectocarp., 1872, p. 54, pi. 2, figs, la, lb; 

 Setchell and Gardner, Alg. N.W. Amer., 1903, p. 237 ; Collins, Holden 

 and Setchell, Phyc. Bor.-Amer. (Exsicc), no. 1034 (in part) (not 

 no. 1387). 



We have accepted Kjellman 's interpretation of Kuetzing 's Ecto- 

 carpiis termmalis and refer here, although not without some hesita- 

 tion, no. 1034 of the Phycotheca Boreali-Americana found growing 

 on stipes of Alaria fistidosa in Unalaska Bay. There is intermingled 

 in our specimens, however, a plant which seems to be a form of 

 Ectocarpus confervoides. We have also referred here a plant found 

 growing on Fucus at Fort Ross, California. 



The creeping filaments in this species anastomose more or less and 

 in some parts of the specimens form almost a parenchymatous basal 

 layer, strongly resembling that of the species of the Myrionemataceae. 

 Nearly every cell of the prostrate filaments gives off an erect filament, 

 a condition characteristic among the Myrionemataceae, but not gen- 

 eral among the Ectocarpaceae. The erect filaments are slender, with 

 rather long cylindrical cells, and bear terminal zoosporangia and either 

 terminal or lateral, sessile or short-stalked, gametangia. The chroma- 

 tophores are clearly band-shaped though short. No, 1387 of the 

 Phj'cotheca Boreali-Americana seems to be entirely made up of a 

 form of Ectocarpus confervoides. 



