to 



CM 



THE MARINE ALGAE OF THE PACIFIC COAST 

 OF NORTH AMERICA 



PART III 



BY 



LIBRA pv 



WILLIAM ALBERT SETCHELL \;ni, 



AND 



NATHANIEL LYON GARDNER 



rjr 



Subclass 3. MELANOPHYCEAE stiz. 



.Multieelhilar 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, erustaceous, globular, hemispherical, filamentous, 

 etc., and with differentiated internal and external tissues; cells with 

 distinct cell Avails, 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. 

 Mclanophyceae Stizenberger, Dr. Ludwig Rabenhorst's Algen 

 22 Sachsens, 1860, p. 36; Rabenhorst, Flora Eur. Alg., vol. 3, 1868, p. 

 CO 393. Fucoideae Agardh, 8yn. Alg. Scand., 1817, p. IX. Melano- 

 CM spermeas Harvey, in Mackay, Flora Hibern., part III, 1836, p. 157; 



