Any of various reef-building hydrocorals of the order Milleporina of tropical marine waters, forming white or yellowish calcareous structures and resembling the true corals of the class Anthozoa. 多孔螅,千孔虫多孔螅目的一种石状水螅建立的珊瑚礁,产于热带海域,形成白色或黄色的石灰质结构,与珊瑚虫纲的真正珊瑚礁相似。