Semaeostomeae

order of cnidarians Semaeostomeae (Semaeostomeae) is an order comprising closely related families of organisms. It contains 3 families with 16 known species. This includes the family groups Cyaneidae, Pelagiidae, and Ulmaridae. Among its members, 8 species are currently classified as threatened (Critically Endangered, Endangered, or Vulnerable). It belongs to Scyphozoa (Scyphozoa).