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428 Uwi/versity of California Publications in Botany [Vol.8
18. Ectocarpus Mitchellae Ilarv.
Fronds aggregated into dense feathery tufts, 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./*. diam., 1-3 times as
long as the diameter below, shorter above ; chromatophores numerous,
small, discoid ; zoosporangia unknown ; gametangia ellipsoidal to nar-
rowly oblong, obtuse, 50-100/t long, 18-35/t 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.
We 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/x 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, 35-45/1 long, 30-35/t broad.