SEA ANEMONES. 217 
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 (A@inyas cyanea, Fig. 76) will serve as a type of this family ; 
Fig. 76.—Blue Minyad, Mixyas cyanea (Cuvier), 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 Actiniada. 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. 
