The Rev. P. Keith on the Structwe of Animals. 96 



tinous globule, with no external organ or apparent orifice.* 

 Professor Grant f has shown that the orders arising out of this 

 division may be increased with advantage to the science ; but 

 those we have adopted are sufficient for general purposes. 



1st. The first order is exemplified in the ^euua Asterias^ or 

 sea-star, with its five radiating lobes ; or in the genus Echinus^ 

 or sea-urchin, with its thousand spines. These genera are 

 common on the shores of England; and when the inclosed 

 animal dies, the empty covering is often to be met with lying 

 on the sea-beach, as it may have been accidentally thrown up 

 and left by the flux and reflux of the tide. 



2d]y. The second order is exemplified in the genus Actinia^ 

 — animal flower, or sea anemone. It is found in great abun- 

 dance on the coasts of the West India islands. It is club* 

 shaped, fig-shaped, or cylindrical, and fixed by the smaller or 

 lower end to rocks, or to stones lying in the sand. To this 

 mode of attachment the Actinia sociata is an exception, the foot 

 being fixed, not immediately to the rock, but to a firm and 

 fleshy tube, that creeps along horizontally, and sticks fast to 

 the surface, resembling in some degree the souche souterrain 

 of the common brakes. At the upper extremity there is a 

 single opening, which is the mouth, leading directly to the 

 stomach, which is a blind sac. The tentacula, when expanded, 

 are said to exhibit an appearance similar to that of the petals 

 of the anemone, whence the name. They are tinged with a 

 variety of bright and brilliant colours, and are the instruments 

 which the animal employs in the seizing of its prey. The 

 Actiniae are very voracious. They will swallow a muscle or an 

 oyster entire ; and after having extracted the internal nutri- 

 ment by the digestive power of the stomach, they will again 

 eject the shell by the same aperture at which it entered. They 

 are also remarkable for their capability of being multiplied by 

 division to any extent. Cut up a single individual into a thou- 

 sand pieces, and each piece will become a complete Actinia^ 

 furnished with all the peculiarities of its species {. 



But an example more within the reach of the zoological 

 student is that of the Medmce^ common on the shores of the 

 British isles; but better known, perhaps, by the vulgar ap- 

 pellation of sea-blubber. They are of a globular form, of a 

 soft and pulpy consistence, and of a shining pale blue colour, 

 dashed with a tinge of violet. You may see them approaching 



* [This statement agrees with the views respecting the Infusoria which, 

 until lately, were entertained by naturalists; but the recent discoveries of 

 Ehrenberg (and it might be added the neglected observations of Gleichen,) 

 have shown that they possess a mouth, many stomachs, and other elements 

 of a complex organization. — Edit.] 



f Lectures at the London University, Nov. 1833. 



X Encyclopedia Britannicay " Animal Flower." 



