The below mentioned article provides a diagram of obelia medusa.
1. It is the slide of Obelia medusa which is a reproductive zooid responsible for giving rise to new progeny.
2. These are saucer-like or umbrella- shaped structures and are developed from blastostyles asexually.
3. All along the margin they bear a ring of tentacles (velum).
4. The inner surface of the dome of saucer bears 4 radial canals.
5. Each radial canal bears a distinct gonad.
6. In the centre, where the radial canals meet, there is present a tubular structure-the manubrium, bearing a rectangular mouth.
7. The medusa are free-swimming zooids.
8. On maturation these gonads release germ cells – the ova and sperms, in the sea water.