1925] Setchell-Gardner: MelanopJiyceae 433 



Saunders, Phyc. Mem., 189S, p. 150, pi. 16; Setchell and Oardner, 

 Phyc. Cont. VI, 1922, p. 415 (f. fypicHs). 



The typical form, growing on the larger brown algae, differs some- 

 what from the variety found growing on C odium as is indicated below. 



Ectocarpus cylindricus f. codiophilus S. and G. 



Plate 51, fig. 14 



Fronds densely caespitose, 3-5 mm. high ; rhizoidal filaments 

 densely intertwined, penetrating the host; erect filaments anastomos- 

 ing and forked at the surface of the host, unbranched above, pili- 

 ferous; gametangia, for the most part, near the base of the erect 

 fronds. 



Growing on Codiiim fragile (Suring.) Ilariot and Codinni 

 SetchcUii Gardner. Carmel Bay, Monterey County, and La Jolla, 

 San Diego County, California. 



Setchell and Gardner, Phyc. Cont. VI, 1922, p. 415, pi. 46, fig. 14 

 and pi. 49, figs. 42-45. 



This form differs from the typical form in having penetrating 

 rhizoidal filaments and in having the gametangia in a dense zone at 

 or near the base of the erect filaments instead of being scattered. 



Ectocarpus cylindricus f. acmaeophilus S. and G. 



Fronds tufted, 7-10 mm. high ; creeping filaments superficial ; 

 erect filaments unbranched, nearly the same diameter throughout ; 

 zoosporangia unknown ; gametangia up to 270/x. long, mostly opposite 

 on the upper part of the erect filaments. 



Growing on Acmaea sp. Carmel Bay, Monterey County, Cali- 

 fornia. 



Setchell and Gardner, Phyc. Cont. VI, 1922, p. 415, pi. 49, fig. 46. 



This form seems to be rare, at least but few specimens have been 

 detected up to the present time. It differs from the typical form in 

 being practically unbranched, except the fructiferous branches. 

 Where branches occur, they seem to arise a.s the result of an injury 

 to the main filament. Also it dift'ers in having the erect filaments 

 more nearly cylindrical throughout. And finally it differs in having 

 the gametangia more often opposite, and generally longer and 

 proportionally narrower. 



