Lowrelief Lettuce Coral

Commonly assigned to the genus Undaria.
This is the only species of Agaricia which can form small, rounded, massive shaped colonies, though many colonies are encrusting.
Corallites are monocentric or in small series, and rows are commonly separated by taller and pointed ridges. Colour is usually dull, grey to yellow. Centres are the same colour as the walls.

Paleontologists call this Undaria crassa. E. Weil places the corals illustrated here with A. agaricites forma agaricites.