l925 ] Setchellr-Gardner: Melanophyceae 431 



family Choristocarpaceae, as diagnosed by Kjellman (1891, pp. 190, 

 191), in having apical growth. The growth in length of the erect 

 filaments in the Choristocarpaceae is by the division of the terminal 

 cell only, whereas in E. chantransiuuh s the meristem extends over 

 a number of cells at the outer or apical end of the filaments. These 

 cells, some 10 to 15 in number, are much richer in cell contents, the 

 terminal cell being the richest of all in the series. This is a xrvy 

 unusual condition for an Ectocarpus. The nearly uniform diameter 

 throughout of the erect filaments and their method of branching 

 resemble to a remarkable degree those characters found in Chan- 

 transia. The gametangia are typically those of Ectocarpus and, not- 

 withstanding the other rather unusual characters, it seems to be most 

 closely related to that genus, but a very distinct species. 



22. Ectocarpus granulosoides S. and G. 



Fronds 2-3 cm. high, profusely branched; main filaments sub- 

 dichotomously branched, all branches suddenly attenuated at the base, 

 corticated below-, secondary filaments mostly alternate, in part secund, 

 strict, long-attenuate, acute, not piliferous ; ultimate ramuli mostly 

 secund, acute; cells of the main filaments 70-80/* diam., 0.5-1 times 

 as long as the diameter, those of the secondary filaments 30-40ju diam., 

 0.3-1 times as long and those of the ultimate ramuli 14-20/x diam.. 

 0.3-1.5 times as long, all slightly constricted at the dissepiments ; 

 chromatophores numerous, discoid in the' older cells, irregularly 

 angular in the ramuli ; cells of the corticating filaments 7-10/t diam., 

 3-4 times as long as the diameter ; zoosporangia unknown ; gametangia 

 secund on the upper side of the ultimate and penultimate ramuli, 

 sessile, subfusiform, asymmetrical, 40-60/*. long, 12-20/* broad. 



Growing on rocks (?). San Pedro, California. 



Setchell and Gardner, Phyc. Cont, VI, 1922, p. 410, pi. 45, figs. 7, 8. 



The very distinct species we have described under the name of 

 Ectocarpus granulosoides has the habit of a small E. granulosus and 

 gametangia of the same general type as found in that species, but 

 considerably smaller. The branching, however, is never opposite, 

 and the acute ramuli gradually attenuated upward recall those of 

 E. acutus, from which our species is amply distinct in both chromato- 

 phore and characters of its gametangia. The branches, particularly 

 the larger, are very suddenly and considerably attenuated at the 

 base, giving the species a striking characteristic of its own, at least 

 within the group of species with discoid chromatophores. 



