The 'Hydroid' or the 'hydractinia echinata', a polymorphic, is generally found on the shells of hermit crabs, and colonies of these creatures are found growing on rocks. The 'tubularia crocea' is another cnidarian, and it is also known as a mussel or algae, or a sea strawberry. The moon jelly is yet another cnidarian and it is also known as the 'Aurelia'. This creature has very small tentacles, weak nematocysts. However, it pays to be careful when handling these creatures because the venom that is present in their nematocysts may affect the mucous membranes of the human being. The 'Brown anemone' or the 'metridium senile' is another cnidarian, and this is an animal that boasts of possessing about 1000 tentacles, each armed with minuscule stinging threads. Its mouth is found at the very center of its shape, which is in the form of a disc. (Sandy Hook's Cnidarians) In the South Carolina Sea Islands, there are more varieties of cnidarians. Some of these are the sea squirts, and the sea oats or the Uniola. (South Carolina Sea Islands) .

             What are the unique features of cnidarians? One of the more important features possessed by this group of organisms is that they have nematocysts, or venom filled stinging cells. These stingers can be used by cnidarians either to capture their prey, or to defend themselves against any form of threat. These nematocysts are generally found on the inside of the digestive system of the creature. (Features unique to Cnidarians and to Ctenophores) These nematocysts come in about twenty-four different forms, and it is the basic difference between the nematocysts that play a major role in the classification of the phylum. Enclosed by a 'cnidocyst', the nematocysts are basically capsules like structures made up of something closely resembling a chitin, within which is found a coiled thread like structure. When the cnidarian closely encounters its prey, what it does is shoot out his thread.