Fig. 5. This specimen appears to be a cluster of corals belonging to the genus Cyathophyllum.
Fig. 6. A magnified sketch of one of the cells of fig. 4.
Fig. 7. A polished transverse section of a coral; the precise relation of this species is not certain.
Fig. 8. This is a very abundant coral in some of the beds of mountain limestone, (Lithodendron fasciculatum, of Phillips.) The specimen figured is from Clifton, near Bristol. The marble cups, and other ornaments, manufactured from the rocks near that place, often exhibit sections of this species.
Fig. 9. A mass of coral from Ingleborough, (Cyathophyllum fungites.)
Fig. 10. A polished slice of a beautiful marble richly marked by the sections of the enclosed corals (Astrea undulata, of Dr. Fleming); from Switzerland: probably from the Oolitic or Jurassic formation.
Fig. 11. Vertical section of a fossil coral, showing the transverse arrangement of the internal cells.
Figs. 12 & 13. These specimens are polished sections of a very beautiful compound coral (Astrea Tisburiensis, of Miss Benett), which occurs in a silicified state in the Portland beds that are quarried at Tisbury, in Wiltshire. Masses of chert (a kind of coarse silex or flint), wholly made up of this coral, are often met with, and when sliced and polished are extremely beautiful and interesting; the originally calcareous fabric of the zoophytes being perfectly transmuted into silex, and the interstices filled up with a similar substance, but of a different colour.[28]
[28] Specimens of the Tisbury Astrea, and of most if not all of the coralline marbles figured and described, may be obtained of Professor Tennant; and also vases, &c. of the various marbles of Derbyshire.