Medusa is the dominant and conspicuous form while the polypoid form is restricted to a short larval stage
Scyphistoma (polypoid stage) produces a series of disc like Ephyrae through transverse fission called Strobilation.
Each Ephyrae develops into adult Aurelia.
Medusa phase is called the Jelly Fish.
Bell margin has many small tentaculocytes.
True velum absent. Instead an inconspicuous velarium is present.
Manubrium is comparatively short and inconspicuous.
Corners of mouth form 4 oral arms.
Canal system complicated and branched.
Muscle derived only from ectoderm.
Ocelli and Olfactory pits are present.
Nematocysts occur all over the bell, tentacles, oral arms and gastric filaments.