It occurs in the Dublin limestone, and resembles a coral or madrepore.
All around is a sea of mounds covered with sand, where the houses stood, mostly built of madrepore, and laid out in streets.
The madrepore pier had been nearly swept away, and the houses near the water were flooded.
The madrepore corals are called reef-builders, but not in the sense of constructors of reefs.
Finally, as a last despairing effort, I took a pencil and began to make a sketch of a madrepore.
The madrepore stone is found among the fossil productions of Ashton.
It is in fact of the shape of a goblet, and its substance is intermediate between that of a sponge and a madrepore.
Third picture: in shallow seas have sprung up isles of madrepore; a cluster of palm trees overhangs them here and there.
Many of these limestones owe their beauty to the fossil corals which they contain, and are hence known as “madrepore marbles.”
One need only glance at the photographs of osmotic productions to recognize the forms of madrepore, fungus, alga, and shell.