SEA ANEMONES. 21/ 



disc-like form, in order to grapple with the rock and other projections 

 at the bottom of the sea, turns itself inwards, forming a sort of purse, 

 which seems to imprison the air. From this results a sort of hydro- 

 static apparatus, aided by which the animals can float in the water 

 and transport themselves from one place to another. The Blue 

 Minyad {Minyas cyanea, Fig. 76) will serve as a type of this family ; 



T^ 



Fig. 76. — Blue Minyad, Minyas cyanea (Cuvierl, natural size. 



its globose, melon-like form is of azure blue, studded with white 

 wart-like excrescences ; it is flattened at its two extremities in its state 

 of contraction, and it has three rows of tentacula, which are short, 

 cylindrical, and white. The internal organs are of a delicate rose 

 colour. Cuvier placed this species among the Echinodermata, but 

 the observations of Lesueur and Quoy, who were acquainted with the 

 living animal, at once showed that its true place was among the free- 

 swimming Actiniadse. Many of the species, which are usually fixed, 

 are still capable of swimming and of inflating their suctorial discs ; 

 therefore it is by no means as yet quite certain that the free habit of 

 Minyas cyanea is constant. 



