A type of simple invertebrate animal with radial symmetry and tentacles, including jellyfish, coral, and sea anemones. These animals have a body wall made of two layers and a central digestive cavity. In modern biology, these are often reclassified into 刺胞动物 cì​bāo​dòng​wù and 栉水母动物 zhì​shuǐ​mǔ​dòng​wù.