Weather-worn or water-worn masses of coral limestone often display the structure of the zoophytes of which they are in a great measure composed, in a beautiful state of sculpture and relief: the silicified or calcified corals appearing as perfect as if fresh from the sea. The mural rocks of coral limestone at Florence Court, the seat of the Earl of Enniskillen, are in many parts encrusted, as it were, with syringopora and other tubular corals, laid bare uninjured by the long and insensible effect of atmospheric erosion. A beautiful illustration of the old aphorism,—"Aqua cavat lapidem non vi sed sæpe cadendo,"—is afforded by the splendid examples of cateniporæ, fungiæ, caryophillæ, sculptured in alto-relievo on the face of the Silurian rocks over which dash the rapids at the Falls of the Ohio.
The silicified zoophytes of the West Indies, and those from Ava and the Sub-Himalayas, form beautiful subjects for the microscope; and chips, or sections, should be prepared in the manner recommended for fossil wood in the same state of mineralization.
LOCALITIES OF FOSSIL ZOOPHYTES.
British localities.—The gravels and sands of the Crag afford most favourable sites for obtaining tertiary zoophytes.
In the London clay at Bracklesham Bay, a species of Astrea (A. Websteri) is often met with attached to flints and pebbles.
In the Greensand of Atherfield, in the Isle of Wight, an elegant coral (Astrea elegans) is by no means rare.
The Greensand gravel-pits, near Faringdon, in Berkshire, abound, as already mentioned, (ante, [p. 228].,) in many kinds of sponges, and other porifera; and the quarries of oolitic limestone in the vicinity of that town, yield the usual corals of the Jurassic formation in great profusion, I know of no locality richer in fossil zoophytes, than Faringdon.[262]
[262] See Excursion, Part IV. of this work.
The quarries of that division of the Oolite called Coral-rag (as in the north-west of Berkshire, Oxfordshire, Gloucestershire, &c.), afford the usual corals of the Oolite.
The Oolite near Bath contains many species, and large masses of a minute coral (Eunomia radiata), are abundant.