Outlines of zoology . maria, Haliclystus, and Depastrum. (2) Discomedusse.—Active forms, often with complicated life history. Aurelia, Pelagia, Cyanea, Rhizostoma. 74 PHYLUM CCELENTERA. (3) Cubomedusse.—Forms with broad pseudo-velum, and other peculiar features. Charybdea. (4) Peromedusas.—Forms with four inter-radial tentaculocysts only. Pericolfa. Class III. Anthozoa ( = Actinozoa) Polypoid forms with well-developed gullet and septa, and circumoraltentacles,(i) Zoantharia or Hexacoralla. (a) Actiniaria. Sea-anemones. Actinia, Anevwnia, Tealia, Cerianthus.{b) Madreporaria. Stone or reef coral
Outlines of zoology . maria, Haliclystus, and Depastrum. (2) Discomedusse.—Active forms, often with complicated life history. Aurelia, Pelagia, Cyanea, Rhizostoma. 74 PHYLUM CCELENTERA. (3) Cubomedusse.—Forms with broad pseudo-velum, and other peculiar features. Charybdea. (4) Peromedusas.—Forms with four inter-radial tentaculocysts only. Pericolfa. Class III. Anthozoa ( = Actinozoa) Polypoid forms with well-developed gullet and septa, and circumoraltentacles,(i) Zoantharia or Hexacoralla. (a) Actiniaria. Sea-anemones. Actinia, Anevwnia, Tealia, Cerianthus.{b) Madreporaria. Stone or reef corals. Asir(ra^ Madrepora^ Fungia, M(Bandrina,(ir) Antipatharia. Horny black corals. Antifathes.(2) Alcyonaria or Octocoralla. Alcyonium (Dead-mens-fingers), Tubipora (Organ-pipecoral), Corallhim (Red coral), Gorgonia, Pennatula (Sea-pen), Monoxenia (non-colonial). Class IV. Ctenophora Delicate free - swimming organisms, generally globular in form,moving by means of eight meridional rows of ciliated plates, or comb-. FiG. 91.—Diagram of a Ctenophore.—After Chun. M., Mouth; 5., sensorjr organ; T., tentacle cut short: SH.,pouch of tentacle; C, ciliated comhs; ^., funnel or central canal;SV.^ paragastric canal running parallel with stomodaeum; C,other canals of the gut; K, one of the meridional canals, bear-ing gonads, running under the bands of ciliated combs. HISTORY OF CCELENTERA 175 like combinations of cilia. The stinging cells are almost alwaysreplaced by adhesive cells. The mouth is at one pole, and leadsinto an ectodermic gullet. The gastric cavity is usually much mesenchyme is very well developed, and includes muscular andconnective cells. At the aboral pole there is a sensory organ, includingan otolith, which seems of use in steering. Here, also, there aretwo excretory apertures. Except in Beroe and its near relatives, thereare two retractile tentacles. All are hermaphrodite. The development
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Keywords: ., bookcentury1900, bookdecade1910, bookidcu3192, booksubjectzoology
