16 THE DEPTHS OF THE SEA. [CHAP. 1. 
the zone of ‘tangles’ for the first few fathoms, and 
in deeper water of the beautiful scarlet sea-weeds 
(floridee). 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 alge. Animals 
swarm in this zone, both as to species and indi- 
viduals, and are usually remarkable for the bright- 
ness 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 echino- 
derms 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 sarsi and 
celticus, Asteracanthion glaciale and rubens, Ophio- 
thrix 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 
