Page:The Depths of the Sea - Wyville - 1873.djvu/48

16 the zone of 'tangles' for the first few fathoms, and in deeper water of the beautiful scarlet sea-weeds (florideæ). It is always under water except at the very lowest ebb of spring tides, when we get a glimpse of its upper border. The laminarian zone produces abundance of vegetable food, and, like the littoral zone, may be divided into subordinate bands distinguished by differently tinted algæ. Animals swarm in this zone, both as to species and individuals, and are usually remarkable for the brightness of their colouring. The molluscan genera Trochus, Lacuna, and Lottia are characteristic of this belt in the British seas.

The Laminarian zone is succeeded by the Coralline zone, which extends to a depth of about fifty fathoms. In this belt vegetation is chiefly represented by coral-like millipores, and plant-like hydroid zoophytes and bryozoa abound. All of the higher orders of marine invertebrates are fully represented, principally by animal feeders. The larger crustaceans and echinoderms are abundant; and the great fishing-banks frequented by the cod, haddock, halibut, turbot, and sole, belong properly to this zone, although they sometimes extend into water more than fifty fathoms deep. Characteristic molluscan genera are Buccinum, Fusus, Ostrea, and Pecten; and among echinoderms in the European seas we find Antedon sarsii and celticus, Asteracanthion glaciale and rubens, Ophiothrix fragilis, and on sand, Ophioglypha lacertosa and albida.

The last belt defined by Forbes as extending from about fifty fathoms to an unknown lower limit is the zone of deep-sea corals. "In its depths the number