428 University of California Publications in Botany {'^o-l. 8 



18. Ectocarpus Mitchellae Harv. 



Fronds aggregated into dense feathery tnfts, 2-8 cm. high, decom- 

 poundly branched, attached by long creeping filaments; yellowish 

 green or olive green on drying; branching alternate, the branches 

 divaricate, attenuated, often ending in short hairs, ultimate ramuli 

 approximated ; cells in the main branches 25-40/a diam., 1-3 times as 

 long as the diameter below, shorter above ; chromatophores numerous, 

 small, discoid; zoosporangia imknown; gametangia ellipsoidal to nar- 

 rowly oblong, obtuse, 50-lOOja long, 18-35/a wide, sessile, mostly secund 

 on the upper side of the branches. 



Growing on limpets and on Phyllospadix in the lower littoral belt. 

 Southern California. 



Harvey, Ner. Bor.-Amer., part I, 1851, p. 142, pi. 12, G; Collins, 

 Notes on New England Algae V, 1891, p. 337 ; Saunders, Phyc. Mem., 

 1898, p. 153, pi. 21, figs. 1, 2; Collins, Holden and Setchell, Phyc. 

 Bor.-Amer. (Exsicc), no. 671. 



AVe have specimens from several collections from the coast of 

 southern California which agree so well with plants from the southern 

 New England coast referred to E. Mitchellae that we cannot satisfac- 

 torily separate them from it. We call attention to the views of Sau- 

 vageau (1896&, p. 39), Collins (1891, p. 337), Saunders (1898, p. 153) 

 and Borgesen (1914, pp. 159-162) as to the possible relation, or even 

 identity, of this species with E. indicus Sond., E. virescens Thuret, 

 and E. Duchassaingianus Grunow, but we have no additional facts to 

 present. 



Our specimens show both mega- and meio-gametangia such as 

 Sauvageau (18966) describes and illustrates for E. virescens Thuret. 



19. Ectocarpus oviger Harv. 



Fronds somewhat densely matted together, 7-15 cm. (up to 22 cm.) 

 high, main filaments densely corticated, dark brown, decompositely 

 branched ; branches mainly alternate, in part secund, strict ; cells 

 cylindrical throughout the frond, not constricted, 60-70/* diam. in 

 the main filaments, 1.5-2.5 times as long as the diameter; chromato- 

 phores discoid, numerous ; zoosporangia uncertain ; gametangia 

 broadly ovoid to subspherical, asymmetrical, sessile or subsessile, alter- 

 nate .or in part secund, promiscuously scattered throughout the 

 branches, 35-45/* long, 30-35/* broad. 



