Gk., herma = cliff or reef; hermatypic corals are referred to as reef-building stony corals;

It is still a mystery why present reef growth began almost worldwide about 6-9E3 years ago; p.39; in ....
Hallock P.; 1997; Reefs and Reef Limestones in Earth History; in Birkeland C. (ed.) Life and Death of Coral Reefs; Chapman and Hall London - UK;