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THE MARINE ALGAE OF THE PACIFIC COAST
OF NORTH AMERICA
PART III
BY
WILLIAM ALBERT SETCHELL
AND
NATHANIEL LYON GARDNER
Subclass 3. MELANOPHYCEAE stiz.
Multicellular thallophytes containing- the green pigment, chloro-
phyll (including xanthophyll), and the brown pigment, phycophaein
thallus varying from simple or slightly branched filaments of a single
row of cells and simple membranes varying from a single layer to
several layers of similar cells, to solid plant bodies of varying form,
e.g., membranous, crustaceous, globular, hemispherical, filamentous,
etc.. and with differentiated internal and external tissues; cells with
distinct cell walls, cytoplasm, at least the outer cells containing definite
chromatophores, carrying the pigments, and typically uninucleate,
although at times becoming multinucleate; assimilation products
various carbohydrates and oils, but never true starch; internal cells
in more complex forms elongated and forming definite mechanical
conducting and storage systems as distinct from the outer tissues of
absorbing and assimilating cells ; multiplication by splitting and by
gemmae of more or less distinctive form ; reproduction by both motile
and non-motile cells, motile cells with one or two lateral, or at least
subapical, cilia ;
non-sexual reproduction by 2-ciliated zoospores or by
aplanospores (Dictyotales) : sexual reproduction by the fusion of
two equal, or of two unequal, motile gametes, or by the fusion of a
smaller motile 2-ciliated sperm and a larger non-motile egg (Lamina-
riales and Fucales) or by the fusion of a smaller 1-ciliated sperm and
a larger non-motile egg (Dictyotales) ; an antithetic alternation of
generations present in many, if not all, species; gametophytes usually
unisexual, similar to, up to extremely different from, the sporophytes.
Melanophyceae Stizenberger, Dr. Ludwig Rabenhorst's Algen
Sachsens, 1860, p. 36; Rabenhorst, Flora Eur. Alg., vol. 3, 1868, p.
393. Fucoideae Agardh, Syn. Alg. Scand., 1817, p. IX. Melama-
spermeae Harvey, in Mackay, Flora Hibern., part III. 1836, p. 157
; :