2005 California Academy of Sciences   cc-by-nc-sa-3.0

Cnidaria (Cnidarians) is a group of animals. There are 11791 species of cnidarians, in 1791 genera and 355 families. This group has been around since the Ediacaran Period. Cnidarians includes groups like Myxozoans, Box Jellyfish, and Stalked Jellyfish.

EOL has data for 21 attributes, including:

Known occurrences, collected specimens and observations of cnidarians