Fig. 261.—Ectocarpus siliculosus
Fig. 262.—Ectocarpus Mertensii
Among the other species we may briefly mention E. granulosus, an abundant and beautiful weed that grows in feathery tufts on rocks and weeds, with elliptical, stalkless pods, quite visible to the naked eye, freely distributed over the opposite branchlets; E. siliculosus, a pale olive, parasitic species with lanceolate stalked pods, pointed and striped; E. sphærophorus, a small, soft, brownish-yellow species, with dense matted branches and spherical pods arranged either opposite to one another or to a branchlet; and E. Mertensii, a pretty species that grows on muddy rocks, freely branched but not matted, and having pods enclosed by the branchlets. The last species is rare, but may be found in Cawsand Bay and a few other localities about Plymouth Sound. The genus includes several other species, but all these are more or less rare.
In the genus Myriotrichia we have two parasitic species with fragile, hair-like, jointed fronds bearing simple straight branches that are covered with transparent fibres. In these the spore-cases are rounded and transparent, and arranged along the main threads; and the dark olive spores are readily visible within. In M. filiformis the branchlets are short, and clustered at intervals, thus giving a somewhat knotted appearance to the threads, and both branches and branchlets are covered with long fibres. The other species—M. clavæformis—is very similar, but may be distinguished by the arrangement of the branchlets, which are not clustered at intervals, but are distributed regularly, and are longer towards the tip of the frond, giving the appearance of minute fox-brushes.
