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1925] Setchell-Gardner: Melanophyceae 435
tophores numerous, discoid ; zoosporangia on short stalks or inter-
calary, globose, about 30/i diam. ; gametangia cylindrical to ovoid,
obtuse or acuminate, lateral, borne on longer or shorter pedicels,
70-150^i long, 2d-50/jl broad.
Growing on Fucus, in the middle of the littoral belt. Pacific
Grove, California.
Setchell and Gardner, Phyc. Cont. VI, 1922, p. 411. Ectocarpus
paradoxus var. pacificus Saunders, Phyc. Mem., 1898, p. 152, pi. 18,
figs. 4-7; Collins, Holden and Setchell, Phyc. Bor.-Amer. (Exsicc),
no. 530.
According to Saunders, his plant, the var. pacificus, differs from
the type of E. paradoxus Mont., in lacking any manifestation of
opposite branching as well as in having the gametangia longer and
more pointed. In these respects and also because it is a shorter plant,
it seems to us to be sufficiently distinct to be separated specifically
from the type, and to be different from any other species known to us.
27. Ectocarpus acuminatus Saunders
Fronds diminutive, attached by a network of delicate rhizoidal
filaments ; erect filaments uniform in size throughout, 1-2 mm. long
cells cylindrical, not constricted, 12-14/x diam., quadrate below, 2-5
times as long above; chromatophores irregular or elliptical disks, more
abundant in the central part of the filament than elsewhere; zoo-
sporangia unknown; gametangia sessile on the creeping filaments or
on the base of the erect filaments or terminal on short filaments arising
directly from the creeping filaments, very long-acuminate, sometimes
tipped with a short hair, often more or less curved, 90-300^ long,
20-30/* broad.
Growing within the coneeptacles of Cystoseira osmundacea and
Halidrys dioica. Central California (Pacific Grove) to southern
California (San Pedro).
Saunders, Phyc. Mem., 1898, p. 149, pi. 14, figs. 1-5; Collins,
Holden and Setchell, Phyc. Bor.-Amer. (Exsicc), nos. 524 and 2142.
The shape of the gametangia would seem to ally this very incon-
spicuous species most closely with E. siliculosus, but the chromato-
phores are described by Saunders as elliptical. We have only dried
material for examination and cannot, therefore, add anything to the
description by Saunders. It is a very curious and seemingly distinct
species. Its habitat, within the coneeptacles of members of the
Fucaceae, seems to have reduced it almost to the state of parasitism,
at least one-half of the plant, being unable to function in food making.
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