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GENUS III. CORYNACTIS (Allman). 



Base expanded, adherent. 



Column versatile, tall; the margin forming a 

 parapet, with no fosse. Surface smooth, without 

 suckers or loopholes ; not invested with any separable 

 epidermis. Substance fleshy or pulpy, pellucid. 



Disk flat, entire, circular. 



Tentacles in several rows, all of the same form ; 

 each consisting of a conical stem and a globular head: 

 perfectly retractile. 



Mouth simple, protrusile ; lip coarsely furrowed : 

 stomach evertile. 



Only one British species exists, C. viridis. 



