Generally hemispherical mass with deeply gouged valleys spearated by steep ridges. However where the top of these ridges normally feature narrow or relatively broader separation lines between opposing septa (like most other brain corals, see Symmetrical Brain Coral or Boulder Brain Coral) they can here feature very wide separation furrows - the grooves - as exemplified by one of the photos shown below, and in particular its red-dotted enlargement. Indeed some specimens can grow unusually wide-angled grooves between separating ridges, but in fact the polyps live in the narrow valleys where their mouths are fed by the many tentacles housed between the septa (the vertical plates).