OLIVE-GREEN AND BROWN 
SEAWEEDS 
HIS subclass contains some of the most remarkable of the 
seaweeds. Itis especially notable for the diversity of its plant 
forms, which range from filaments to plants which appear to have 
stems and leaves (Sargassum). The species vary in size from very 
small fronds to those of immense size (the Laminariacee). It in- 
cludes Fucus (the rockweeds), a very conspicuous genus, which 
furnishes fully three fourths of the vegetable covering of the 
tidal rocks in the localities in which it grows. 
ORDER ECTOCARPACEA 
This order comprises many species of branched, filamentous 
plants, some of which are of hair-like fineness and form beautiful 
feathery tufts of brownish or olive-green color. They resemble, 
except in their tawny color, the green alga Cladophora. 
The name is derived from Greek words meaning “outside” 
and “fruit,” the spores of the plants being borne on the branches. 
The species are determined by the arrangement of the spores, 
according as they are in the pod-like branches, in groups, or in 
cases on stalks. Since these differences are not perceptible to 
the naked eye, it is impracticable to describe many species, or for 
the amateur collector to try to separate them. 
Genus Ectocarpus 
E. littoralis. Filaments fine, in dense tufts, interwoven, six to twelve 
inches long; pod linear in the substance of the branches; color olive- 
green. This is the most common species of Hetocarpus, and grows abun- 
dantly everywhere, appearing like large, fine, dull-green plumes. (Plate IX.) 
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