1925] Setchell-Gardner: Melanophyceae 425 



Growing on C odium fragile in the lower littoral belt. Near the 

 entrance to Tomales Bay, Marin County, California. 



SeteheU and Gardner. Phyc. Cont. VI, 1922, p. 407, pi. 47, figs. 

 18-23. 



This very small species has the general appearance of a form of 

 Ectocarpus confer voides, but the cells are short and the filaments very 

 slightly constricted at the partitions. It seems, in these respects, 

 nearer to E. acutus and E. corticulatus, possibly bearing something 

 of the same relation to these species that the dwarf forms of E. con- 

 fervoides do to the typical form. Ectocarpus eramosus, however, is 

 not readily to be referred as a dwarf form of either E. acutus or E. 

 corticulatus and is consequently to be kept separate, at least for the 

 present. 



15. Ectocarpus luteolus Sauv. 



Prostrate filaments moniliform, irregularly branched, covering, or 

 even occupying, the injured cells on the surface of the host, even 

 occasionally penetrating slightly inward, not anastomosing, but form- 

 ing an irregular and confused layer of almost parenchymatous aspect 

 emitting tortuous rhizoidal filaments from its lower cells; erect fila- 

 ments very short, 100-300//. high, terminating in delicate hairs (or, at 

 times, in seriate gametangia), simple or with a few branches from 

 near the base ; cells of the erect filaments short, swollen, and nearly 

 globular below, cylindrical and longer above, about 8/t broad, 1.5 times 

 as long as broad ; ehromatophores few in each cell, band-shaped ; zoo- 

 sporangia terminal on short basal branchlets, oblong-ellipsoidal, 

 26-30/x long, 16-18/* broad ; gametangia narrowly cylindrical, con- 

 sisting of single or double rows of loculi, 30-80/x (in ours about 30-45/*) 

 long, 7-13/a (in ours 11-13//) broad. 



Forming small expansions on the surface of the lower portion of 

 Pelvetiopsis limitata f. typica Gard. Central California (San 

 Francisco). 



Sauvageau, Sur. quelq. alg., 1892, p. 79 (p. 42 in repr.), pi. II, 

 figs. 14-19; Collins, Holden and Setchell, Phyc. Bor.-Amer. (Exsicc), 

 no. 1233. Streblonema lutecium De-Toni, Syll. Alg., vol. 3, 1895, 

 p. 575. 



Ectocarpus luteolus Sauv. is one of the species which seems inter- 

 mediate between Ectocarpus and Streblonema. It does penetrate the 

 host slightly and occasionally, but it seems to grow on the lower 

 abraded portion of the host, filling the hollows between and even the 



