An order of cnidarian subclass Hexacorallia commonly known as mushroom anemones. These polyps are morphologically intermediate between members of the hexacorallian orders Scleractinia (corals), with which they share features of internal anatomy, weak musculature, and certain types of nematocysts (intracellular stinging capsules used in food capture and defense), and Actiniaria (anemones), which they resemble in lacking a calcareous skeleton. All three animals have paired, coupled mesenteries that are added around the entire periphery of the polyp. Like Actiniaria and Scleractinia, Corallimorpharia contains some members that are solitary and some that are clonal (reproduce asexually to produce genetically identical individuals that live physically separate from one another); however, by contrast with Scleractinia, Corallimorpharia has no colonial members (clonemates that remain attached to one another).