Jellyfish

Alternative names for groups of jellyfish are scyphomedusae, stauromedusae, cubomedusae, and hydromedusae. These may relate to an entire order or class.
Terminology
The word jellyfish (which has been in common usage for more than a century) is used to denote several different kinds of cnidarians, all of which have a basic body structure that resembles an umbrella, including scyphozoans, staurozoans (stalked jellyfish), hydrozoans, and cubozoans (box jellyfish). Some textbooks and websites refer to scyphozoans as "true jellyfish".