Identifier: guidetofossilinv00brit (find matches)
Title: A guide to the fossil invertebrate animals in the Department of geology and palaeontology in the British museum (Natural history)
Year: 1907 (1900s)
Authors: British Museum (Natural History). Dept. of Geology Bather, Francis Arthur, 1863-
Subjects: Fossils
Publisher: London, Printed by order of the Trustees
Contributing Library: Smithsonian Libraries
Digitizing Sponsor: Biodiversity Heritage Library

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Anthozoa (Flower-animals, also called Actinozoa or Rayed animals) include the sea-anemones, nearly all the stony corals, precious coral, sea-fans, sea-pens, and deadmens fingers. In these the mouth is pushed inwards, so asto form a tube; the body-cavity is divided by partitions,called mesenteries, which consist of mesogloea covered with endoderm; the reproductive cells are derived from this endoderm and are set free into the body-cavity whence they pass to the exterior through the mouth. The Scyphozoa (Cup-animals) comprise the larger jelly-fishes. Some place them with the Hydrozoa, which they 44 GUIDE TO THE FOSSIL INVERTEBRATE ANIMALS. Gallery X. resemble in the simple mouth and absence of mesenteries; others place them with the Anthozoa, which they resemble in the origin of the reproductive cells. Other features,however, distinguish them from both these Classes. Class SCYPHOZOA. Many Coelentera being soft-bodied animals can leave no fossil traces except impressions that they may have formed

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Fig. 18. A fossil jelly-fish, Rhizostomites lithographicus, one of the Scypho-medusae, from the Kimmeridgian of Solenhofen. a, imprint on the exposed surface of the Lithographic Stone, about ^ natural size. (FromE. Ray Lankester's Extinct Animals. After Walcott.) b, diagram interpreting the marks seen in a. (After Brandt.) c, diagram to show how the imprint is formed by the jelly-fish settling down on the mud; a vertical cut has been made through the mud and through the middleof the jelly-fish. (After Walcott.) on a sandy shore; these of course can only be left by free-swimming jelly-fishes or medusae, not by fixed forms. Such impressions are actually known in various rocks from the COELENTERA — JELLY-FISHES. 45 Cambrian Epoch onwards, and all appear to belong to a Gallery X. single Sub-Order of Scyphozoa, the Rhizostomata (Root-mouths), so called because the four lips of the mouth are drawn out and each fused by its edges into a tube pierced by small openings through which the anima

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