There are some grey area corals that don’t neatly fit into the “skeleton” vs. “no skeleton” classification. One such example is a pipe organ coral. It is an Octocorallia soft coral that grows a distinctive red calcium carbonate skeleton. Another example is the topic of this article, the clove polyp. Clove polyps do not form a skeleton that is as obvious as a pipe organ coral, but they do form a connected network of stolons from which their polyps extend. You can see why the official classification of corals goes by the count of polyp segments and not how stony or soft a coral is because it turns out that there are varying degrees of skeleton formation.
