ON THE ORGANS OR RADIATED ANIMALS. 
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more rows around the mouth, like the metals of a compound flower, from which 
resemblance this class has been long known as Animal-flowers and Sea-anemones. 
The numerous species that inhabit our shores afford the student ample oppor¬ 
tunities for investigating this elaborate structure, and studying their singular 
habits. When observed expanded in their native haunts, they present an 
interesting spectacle to the admirer of Nature. Sometimes they are seen 
suspended from the vaults of submarine caves, or adorning the perpendicular 
sides of rocks with a gorgeous floriform tapestry: other species fr quent the 
sandy beach, and seek a temporary shelter from any threatened danger amongst 
the particles of their silicious abode; whilst wandering along the rocky beach, 
other beautiful forms of Actinidce ( A . equina) may be seen enjoying the vivifying 
influence of the solar rays at the bottom of the shallow pools of water left by 
the ebbing tide, where they ornament the rocks like so many flowers with their 
chaste and beautiful colours. These interesting beings are infinitely sensible 
to light and to meteoric influences in general, and expand and contract their 
tentacules in proportion as the state of weather is congenial or otherwise to their 
feelings, the shadow of a passing cloud, dr the slightest undulation of the water, 
is sufficient to cause them to withdraw their tentacules, contract their bodies, 
and remain like an inanimate mass until the menaced danger has passed. 
The exquisite sensibility manifested by these simple beings induced the Abbe 
Dicquemare to believe that the expansion of the tentacula of Actinice was a 
more certain indication of fine weather than even the rising of the barometer. 
The Tioanthida are destitute of any solid organ of support, but the cutaneous 
system is distinctly developed, and intimately united to the subcutaneous 
muscular tissue, which conjointly form the resisting walls of their cylindrical 
bodies. The dermis is impregnated with a pigment of the most brilliant hues, as 
blue, red, green, yellow, &c., and from the numerous pores upon its surface an 
abundant viscous secretion exudes, which has the property of exciting a slight 
degree of inflammation in the skin, when brought into contact with it. This 
poisonous fluid may serve for destroying the victims of these predaceous animals 
when seized in the tenacious grasp of their numerous tentacula. These prehensile 
organs are tubular prolongations of the musculo-cutaneous integument, and are 
the media by which the respiratory chambers, situated between the walls of the 
stomach and the tegumentary membrane, communicate with the water; each 
tentaculum is a conical tube, the base of which opens into the space just 
described, whilst the free apex terminates in a small orifice surrounded by a 
sphincter muscle, through which the water is admitted into or ejected from the 
respiratory chambers. The membrane lining these spaces is copiously supplied 
with vibratile ciliae, the incessant action of which induces currents of water to 
meander over its surface. The faculty these animals possess of distending their 
