Examples from the Web for cnidaria
Real parasites are not numerous among the sponges and cnidaria.
On the other hand, the cnidaria develop into higher radial (star-shaped) persons, and the platodes into lower bilateral persons.
In this way is formed a ring of tentacles, the most characteristic organs of the Cnidaria.
Flagellated epithelium is especially found in the cnidaria and platodes; ciliated epithelium mostly in the vermalia and mollusca.
I began with the consideration of the simplest sponges (olynthus) and cnidaria (hydra).