Echinodermata

Definitions

  • WordNet 3.6
    • n Echinodermata radially symmetrical marine invertebrates including e.g. starfish and sea urchins and sea cucumbers
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Webster's Revised Unabridged Dictionary
    • n. pl Echinodermata (Zoöl) One of the grand divisions of the animal kingdom. By many writers it was formerly included in the Radiata.☞ The species usually have an exterior calcareous skeleton, or shell, made of many pieces, and often covered with spines, to which the name. They may be star-shaped, cylindrical, disk-shaped, or more or less spherical. The body consists of several similar parts (spheromeres) repeated symmetrically around a central axis, at one end of which the mouth is situated. They generally have suckers for locomotion. The group includes the following classes: Crinoidea, Asterioidea, Ophiuroidea, Echinoidea, and Holothurioidea. See these words in the Vocabulary, and also Ambulacrum.
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Century Dictionary and Cyclopedia
    • echinodermata A phylum or subkingdom of metazoic animals; the echinoderms. They represent one of the most distinct types of the animal kingdom, agreeing with cœlenterates in having a radiate or actinomeric arrangement of parts, usually pentamerous or by fives or tens, a digestive canal, a water-vascular or ambulacral apparatus, a true blood-vascular system, and the integument indurated by calcareous deposits, as either granules, spicules, or hard plates forming a shell. The alimentary canal is distinct from the general body-cavity; there is a deuterostomatous oral orifice or mouth, and usually an anus. The sexes are mostly distinct. The species undergo metamorphosis; the free-swimming ciliated embryo is known as a pluteus, in some cases as an echinopædium (see cut under echinopædium); the adult form is usually assumed by a complicated kind of secondary development from the larval form, which is mostly bilateral. The Echinodermata were so named by Klein in 1734, and in Cuvier's system were the first class of his Radiata; they are still sometimes reduced to a class with the Cælenterata. As a subkingdom they are divisible into four classes: Crinoidea, Echinoidea, Asteroidea, and Holothurioidea, or the crinoids, sea-urchins, starfishes, and seacucumbers. As a class they are sometimes divided directly into seven orders: Echinoidea (sea-urchins), Asteroidea (starfishes), Ophiuroidea (sand-stars and brittle-stars), Crinoidea (feather-stars), Cystoidea (extinct), Blastoidea (extinct), and Holothurioidea (sea-cucumbers). All are marine. Also Echinoderma.
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Etymology

Webster's Revised Unabridged Dictionary
NL., fr. Gr. 'echi^nos hedgehog, sea urchin + de`rma -atos, skin

Usage

In literature:

During this voyage notes of the habitats of considerably more than a thousand species of Mollusca and Echinodermata were carefully registered.
"Voyage Of H.M.S. Rattlesnake, Vol. 2 (of 2)" by John MacGillivray
Still more striking cases could be given with respect to the Echinodermata.
"The Variation of Animals and Plants Under Domestication, Volume II (of 2)" by Charles Darwin
In Echinodermata a certain amount of mesenchyme appears before the epithelial mesoderm, which is formed later as gut-diverticula.
"Encyclopaedia Britannica, 11th Edition, Volume 9, Slice 3" by Various
ECHINODERMATA, absence of secondary sexual characters in, i.
"The Descent of Man and Selection in Relation to Sex" by Charles Darwin
Echinodermata, 33, 43, 44, 122.
"Stories of the Universe: Animal Life" by B. Lindsay
Echinodermata, 108; classification of, 120.
"Elementary Zoology, Second Edition" by Vernon L. Kellogg
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