Fig. 12. A remarkable coral (Petraia, of Munster), from the Devonian strata.
Figs. 13 & 14, are sections of Cyathophylla, like figs. 1, 2, 3, to exhibit the internal structure.
Figs. 15 & 16. Two elegant simple corals (Caryophyllia centralis, of Mantell), from the chalk of Kent. The form and disposition of the lamellæ of the cavity, as seen at the upper part of the specimens, are shown at a and b.
Fig. 17. A transverse and polished section of a species of Cyathophyllum, from the Devonian strata, at Blackenberg on the Rhine.
Plate XXXVII.
PLATE XXXVII.