Strictly classified, cross peony corals should not belong to stony corals, and if I remember correctly, they should be a type of fungal coral.
There is no need to divide it into another category here, because it is not a strict popular science article, and there are not many fungal corals.

Photographed on September 9, 2017 in Dong Ping Chau, Hong Kong
Cross peony corals are still very common on the seabed of Shenzhen, especially in the submarine reef of Dapeng Bay, which is the dominant variety of corals.
Among the corals in Shenzhen, it is one of the corals that I can clearly distinguish at a glance.
Photographed on September 17, 2017 in Dong Ping Chau, Hong Kong
Photographed on September 24, 2017 in Dapeng Ji'ao Bay
Published Corals (click to view):
Shield gyro coral
Frost antler corals
Cannonball Flower Coral
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