Cnidaria: Information and resources for researchers studying all aspects of cnidarian biology.
Cnidaria (Coelenterata): An attractive and informative site from the Tree of Life Project, by Daphne G. Fautin and Sandra L. Romano.
Coral Health and Monitoring Program: Services to help improve and sustain coral reef health throughout the world. Part of an international network of coral reef researchers.
Introduction to the Cnidaria: Sea anemones, medusae, jellyfish, corals.
Phylum Cnidaria: General information about the phylum that includes jellyfish, coral, hydra.
Reef Corals of the Indo-Malayan Seas: Identification key to the corals of the waters of Indonesia and adjacent territories, including members of classes Hydrozoa (hydrocorals), and Anthozoa (black corals, stony corals, soft corals and sea pens). Includes about 3500 colour pictures and interactive distribution maps.
Underwater Field Guide to Cnidarians of Ross Island & McMurdo Sound, Antarctica: Spectacular photographs of Antarctica's sea anemones, jellyfish, hydroids and soft coral.