CN ID ARIA 



71 



C. Hexacorallia. 



Sub-Order 3. Antipatharia (horn corals). With 6 or 24 simple tentacles. Colonies 



with horny axial skeleton. Antipathes (6 tentacles, only 2 developed septa), 



Gerardia (24 tentacles and septa). 

 Sub-order 4. Madreporaria (stone corals). 



Mostly colonies, more rarely in- 

 dividuals with strongly developed 



calcareous skeleton. 6n simple ten- 

 tacles, and septa present in great 



numbers and variously arrranged. 



Madrepora, Astroides, Fungia, Astrcea, 



Mceandrina, Cladocora, Caryophyllia, 



Flabellum. 

 Sub -Order 5. Actinaria (flesh corals). 



Mostly individuals with 611 tentacles, 



and septa generally in considerable 



numbers and varied arrangement. 



Without skeleton. Cerianthus, Zoan- 



thus, Actinia, Anemonia, Adamsia, 



Edivardsia. 



Order 2. Scyphomedusse (Acraspeda). 



Mostly free-swimming individuals of bell- 



or disc-shape, in which the mesodermal 



supporting lamella is developed into 



a large gelatinous mass. The ecto- 



dermal oesophagus lies within a gastric 



peduncle which hangs down from the 



middle of the subumbrella. The 4 



radial pouches of the Scyphula 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. With 



tufts of gastral filaments. A true velum 



is wanting ; in its place, marginal 



lobes, containing processes of the 



gastro-canal system are present. 

 A. Medusce with deeply vaulted um- 

 brella. The 4 radial gastric pouches and 

 the septa which separate them more or 

 less clearly retained. 

 Sub -Order 1. Stauromedusse. 4 septa 



retained (Lucernaria) 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 8 



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. With 4 



; 



FIG. 63. Kophobelemnon Leuckartii. 



