Actinia Definition

Actinia Sentence Examples

• The most familiar Anthozoan is the common sea-anemone, Actinia equina, L., and it will serve, although it does not form a skeleton or corallum, as a good example of the structure of a typical Anthozoan polyp or zooid.

• The individual animal or zooid of Actinia equina has the form of a column fixed by one extremity, called the base, to a rock or other object, and bearing at the opposite extremity a crown of tentacles.

• In Actinia and its allies, and most generally, though not invariably, in Anthozoa,the stomodaeum is not circular, but is compressed from side to side so as to be oval or slit-like in transverse section.

• In Actinia, as in all Anthozoan zooids, the coelenteron is not a simple cavity, as in a Hydroid, but is divided by a number of radial folds or curtains of soft tissue into a corresponding number of radial chambers.

• In common with all Coelenterate animals, the walls of the columnar body and also the tentacles and peristome of Actinia are composed of three layers of tissue.