MARINE PLANTS.
The Algæ.--Zostera marina.--The Ulvæ and Enteromorphæ.--The Fuci.
--The Laminariæ.--Macrocystis pyrifera.--Description of the
Submarine Thickets at Tierra del Fuego.--Nereocystis lutkeana.
--The Sargasso Sea.--The Gathering of edible Birds'-nests in the
marine Caves of Java.--Agar-Agar.--The Florideæ.--The
Diatomaceæ.--Their importance in the economy of the Seas 390