Actinozoa is an obsolete term in systematic zoology, first used by Henri Marie Ducrotay de Blainville about 1834, to designate animals the organs of which were disposed radially about a centre. Systematic was a hard rock band from California, USA. The band was one of the first signings to Metallica drummer Lars Ulrichs record label, The Music Company (via Elektra Records). ... Zoology (Greek zoon = animal and logos = word) is the biological discipline which involves the study of animals. ... Henri Marie Ducrotay de Blainville (September 12, 1777 - May 1, 1850) was a French zoologist and anatomist. ...

De Blainville included in his group many unicellular forms, sea anemones, corals, jellyfish, hydroid polyps, echinoderms, polyzoa and rotifera. Families Many, see text. ... Orders Scleractinia Corals are gastrovascular marine cnidarians (phylum Cnidaria; class Anthozoa) existing as small sea anemone-like polyps, typically forming colonies of many individuals. ... Orders Stauromedusae Coronatae Semaeostomae - Disc jellyfish Rhizostomae Jellyfish (also called jellies or sea jellies as they are not true fish, nor are they made of jelly) are animals that belong to Phylum Cnidaria, included in the class Scyphozoa (from Greek skyphos cup and zoon animal). The name jellyfish is also... Classes Asteroidea Concentricycloidea Crinoidea Echinoidea Holothuroidea Ophiuroidea Echinoderms (Echinodermata) is a phylum of marine animals found in the ocean at all depths. ... Classes Seisonoidea Bdelloidea Monogononta The rotifers make up a phylum of microscopic, pseudocoelomate animals. ...

Thomas Huxley afterwards restricted the term. He showed that in de Blainville's group there were associated with a number of heterogeneous forms a group of animals characterized by being composed of two layers of cells comparable with the first two layers in the development of vertebrate animals. Such forms he distinguished as Coelentera, and showed that they had no special affinity with echinoderms, polyzoa, etc. He further divided the Coelentera into a group Hydrozoa, in which the sexually produced embryos were usually set free from the surface of the body, and a group Actinozoa, in which the embryos are detached from the interior of the body and escape generally by the oral aperture. Huxley's Actinozoa comprised the sea-anemones, corals and sea pens, on the one hand, and the Ctenophora (comb jellies) on the other. Thomas Huxley Thomas Henry Huxley F.R.S. (May 4, 1825 - June 29, 1895) was a British biologist, known as Darwins Bulldog for his defence of Charles Darwins theory of evolution. ... Look up Heterogeneous on Wiktionary, the free dictionary A heterogeneous compound, mixture, or other such object is one that consists of many different items, which are often not easily sorted or separated, though they are clearly distinct. ... Orders Actinulida Capitata Chondrophora Filifera Hydroida Siphonophora Trachylina Organisms that are in Class Hydrozoa come from the Phylum Cnidaria. ... Families Suborder Sessiliflorae Anthoptilidae Chunellidae Echinoptilidae Funiculinidae Kophobelemnidae Protoptilidae Renillidae Scleroptilidae Stachyptilidae Umbellulidae Veretillidae Suborder Subselliflorae Pennatulidae Pteroeididae Virgulariidae Sea Pens are colonial marine cnidarians belonging to the order Pennatulacea. ... Classes Tentaculata Nuda Ctenophores are jellyfish-like animals commonly called comb jellies, sea gooseberries, sea walnuts, or Venus girdles. ...

Modern biology confirms Huxley's criticism of De Blainville's Actinozoa, and upholds Hydrozoa, but it is now known that the Ctenophora are only distantly related to jellyfish and their relatives, so Huxley's Actinozoa and Coelentera are no longer used. Modern taxonomies place the comb jellies in their own phylum Ctenophora and the jellyfish, sea anemones, and Hydrozoa together in the phylum Cnidaria. Orders Actinulida Capitata Chondrophora Filifera Hydroida Siphonophora Trachylina Organisms that are in Class Hydrozoa come from the Phylum Cnidaria. ... Phylum (plural: phyla) is a taxon used in the classification of animals, adopted from the Greek phylai the clan-based voting groups in Greek city-states. ... Classes Tentaculata Nuda Ctenophores are jellyfish-like animals commonly called comb jellies, sea gooseberries, sea walnuts, or Venus girdles. ... Orders Actinulida Capitata Chondrophora Filifera Hydroida Siphonophora Trachylina Organisms that are in Class Hydrozoa come from the Phylum Cnidaria. ... Classes Anthozoa - Corals and sea anemones Cubozoa - Sea wasps or box jellyfish Hydrozoa - Hydroids, hydra-like animals Scyphozoa - Jellyfish Cnidaria (from New Latin cnida nematocyst, fr. ...

References

• This article incorporates text from the 1911 Encyclopædia Britannica, which is in the public domain.