Cnidaria
The Cnidarians are stinging jelly-like animals.
Cnidarian comes from a Greek word meaning
stinging nettles. All cnidarians have stinging
cells called nematocysts. They sting their prey
with the tentacles surrounding their mouth. Then
it pulls its anesthetized prey into its mouth.
The cnidarians used to be called Coelenterata
which means "stomach mouth" because they
have only one opening into its body. It is all
stomach. For the first time, animals seem to
have some kind of symmetry or mirror image
of itself on its body. The cnidaria's symmetry
is called radial symmetry. Hydras, Corals,
Jellyfish, and Sea anemones are Cnidaria.
-Pinegreenwoods Montessori
Montessori Zoology