494 CLASS ECHINODERMATA. 
also crawl upon this base or detach it altogether, and swim, 
or suffer themselves to be carried away by the motion of the 
waters. They are most frequently limited to the movement 
of expanding more or less the aperture of the mouth, which 
also serves the purposes of an anus. It is surrounded with 
tentacula more or less numerous, and leads into a stomach 
which terminates in a cul-de-sac. Between this interior sac 
and the external skin, is an organization tolerably com- 
plicated, but still rather obscure, consisting chiefly of vertical 
and fibrous leaflets, to which the ovaries adhere, similar to 
threads very much contorted. The intervals of these leaflets 
communicate with the interior of the tentacula, and it appears 
that the water can enter there and come out by little orifices 
around the mouth; at least the actinia sometimes ejaculates _ 
it in this way. 
AcTINIA, L. 
Their fleshy body, often adorned with lively colours, deve- 
loping numerous tentacula, placed round the mouth, on several 
ranges like the petals of a double flower, has occasioned the 
name of sea anemone to be bestowed upon them. They are 
amazingly sensible to light, and open or close according as 
the day is more or less fine. When they retract their tenta- 
cula, the aperture from which these organs issue, contracts, 
and closes upon them like that of a purse. 
Their power of reproduction is scarcely less than that of 
the armed polypi. They shoot forth again the parts which 
have been cut, and multiply by division. Their ordinary 
generation is viviparous. ‘The little actiniz pass from the 
ovary into the stomach and come out through the mouth. 
These zoophytes dilate their mouth considerably when they 
are hungry. ‘They devour all sorts of animals, and especially 
crustacea, testacea, and small fishes, which they seize with 
their tentacula, and digest pretty quickly. 
