…a class of coelenterates which includes hydras and Portuguese men-of-war. Many of them are colonial and some kinds have both polypoid and medusoid phases…
…a colonial coral-like hydrozoan, the heavy external skeleton of which forms reefs. The polyps bear nematocysts which can inflict painful stings…
…a minute freshwater coelenterate with a stalk-like tubular body and a ring of tentacles around the mouth…
…a coelenterate of an order which includes the hydras. They are distinguished by the dominance of the polyp phase…
…a coelenterate of the class Hydrozoa, such as a hydra or Portuguese man-of-war…
…a sedentary colonial coelenterate with upright branching stems bearing minute cups in which the polyps sit…
…a floating colonial coelenterate with a number of polyps and a conspicuous float. It bears long tentacles which are able to inflict painful stings and occurs chiefly in warm seas…
