FAUNA AND FLORA OF THE BRITISH ISLES.
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range throughout it. Even, in certain localities, where they are found in shallower water inhabiting the region of corallines, there are reasons, as will afterwards be shown, for believing that such cases are apparent anomalies which may be explained by reference to geological changes.
The following table may be useful as exhibiting at a glance the characteristic features of the several zones of depth in the British Seas.
Table of the Regions of Depth of the British Seas.
| Characteristic Plants. | Characteristic Animals. | |
| I. Littoral Zone. The tract between tide marks. |
First Subregion. Fucus canaliculatus.
Second Subregion. Lichina.
Third subregion. Fucus articulatus.
Fourth Subregion.
Fucus serratus.
|
Patella vugata throughout.
First Subregion. Littorina rudis.
Second Subregion. Mytilus edulis.
Third subregion. Littorina littorea. Purpura lapillus.
Fourth Subregion.
Littorina neritoides. Trochi.
|
| Himanthalia lorea. | ||
| II. Laminarian Zone. Tract between low-water mark and 15 fathoms. |
Subregio superior Laminariæ.
Rhodomeniæ. Delesseriæ.
Subregio inferior
Nullipora.
|
Trochus Ziziphinus. Lacunæ. Patella pellucida. Patella Cærulea. |
| III. Region of Corallines. 10 to 50 fathoms. |
? | Hydroid zoophytes throughout
Subregio superior Fucus antiquus.
Pullastra virginea. Pecten maximus.
Subregio inferior
Pleurotoma teres.
Turbinolia milletiana. |
| IV. Region of deep Sea Corals. 50 fathoms to beyond 100. |
0 |
Subregio superior Neæræ.
Celleporæ. Brachiopoda. Ditrupa.
Subregio inferior
Astrophyton.
Cidaris. Oculina. Primnoa. |
