88 LUNDY ISLAND. 



polype, having many highly-sensitive tentacles, which 

 expand like the rays of a star around the mouth. 

 When in health, and undisturbed, these exquisite 

 organs are stretched in all directions, resembling so 

 many threads of spun glass ; but on the slightest 

 touch, or even on a shock being given to the vessel 

 in which the animal is kept, . the tentacles contract 

 into shrivelled and shapeless lumps, and the whole 

 animal shrinks down to the bottom of its cup-like cell. 



Another of the plant-like forms of compound life, 

 but belonging to a class of higher organic rank, was 

 Crisia eburnea, called by Ellis the Tufted Ivory Co- 

 ralline, an appellation which well indicates three of 

 its prominent qualities ; its stony coralline texture, 

 its delicate whiteness, and its habit of growth in little 

 bushy tufts, about an inch in height. The cells here 

 are short tubes, and the polypes, which project from 

 them, have a much higher organisation, a more com- 

 plex form, and more precise and energetic motions, 

 than those of the Plumularia. The tentacles in this 

 species are not contractile in their own substance, but 

 are capable of being closed together in a parallel 

 bundle, and of being withdrawn into the body, as 

 into a sheath. They are again expanded by the 

 turning inside-out of the integuments which sheathe 

 them, just as a stocking or a glove is reversed. 



The substance of the skeleton in the class of ani- 

 mals to which the Crisia belongs, is composed of 

 lime ; hence it is brittle, and of a stony hardness. If 

 a small portion be held to the flame of a candle, there 



