Text-book of comparative anatomy . lonieswith horny axial skeleton. Antipathcs (6 tentacles, only 2 developed septa),Gcrardia (24 tentacles and septa). Sub-order 4. Madreporaria (stone corals).— Mostly colonies, more rarely in-dividuals with strongly developedcalcareous skeleton. 6?i simple ten-tacles, and septa present in greatnumbers and variously , Astroidcs, Fungia, Astrcea,Mtmndriiut, Cladocora, CaryophylUa,Flabellum. Sub-Order 5. Actinaria (flesh corals).—Mostly individuals with &n tentacles,and septa generally in considerablenumbers and varied skel
Text-book of comparative anatomy . lonieswith horny axial skeleton. Antipathcs (6 tentacles, only 2 developed septa),Gcrardia (24 tentacles and septa). Sub-order 4. Madreporaria (stone corals).— Mostly colonies, more rarely in-dividuals with strongly developedcalcareous skeleton. 6?i simple ten-tacles, and septa present in greatnumbers and variously , Astroidcs, Fungia, Astrcea,Mtmndriiut, Cladocora, CaryophylUa,Flabellum. Sub-Order 5. Actinaria (flesh corals).—Mostly individuals with &n tentacles,and septa generally in considerablenumbers and varied skeleton. Cerianthus, Zoan-thus, Actinia, Anemonia, Adamsia,Edwardsia. Order 2. Scyphomedusse (Acraspeda). Mostly free-swimming individuals of bell-or disc-shape, in which the mesodermalsupporting lamella is developed intoa large gelatinous mass. The ecto-dermal cesophagus lies within a gastricpeduncle which hangs down from themiddle of the subumbrella. The 4radial pouches of the Scypliula de- generate in the higher forms. The. exumbrellar and subumbrellar walls of the peripheral portion of the gastric cavity grow together in such a way that only a variously developed system of radial gastro-canals remains. AVith tufts of gastral filaments. A true velum is wanting; in its place, marginal lobes, containing processes of the gastro-canal system are Mcdusce with deeply vaulted um-brella.—The 4 radial gastric pouches andthe septa which separate them more orless clearly 1. Stauromedusse.—4 septa retained (Luccrnarict) or reduced to 4 pillars (Tessera], 4 or 8 gonades in the subumbrellar wall of the 4 gastric pouches, without sensory bodies (rhopalia). Lucernaria (attached, with S marginal lobes, each carrying a tuft of stinging batteries). Tessera (free, with-out distinct marginal lobes, with 8 tentacles).Sub-Order 2. Peromedusse.—The 4 septa reduced to 4 pillars, in consequence of which the 4 gastric pouches are united into a circumferential sinus
Size: 959px × 2606px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1890, booksubjectanatomycomparative
