THE SEA MUSHROOM. 



105 



in figure and beauty of colouring. Like the aster 

 or the pink, they have a bulbous star-like disc ; and 

 though some are minute, others vary in size from 

 half an inch to two inches in diameter. 



It will be well, however, here to notice an animal, 

 which is a kind of borderer on the coral race. Let 

 a polyp be supposed to de- 

 posit within itself a calca- 

 reous or earthy secretion, 

 to form a rude skeleton or 

 internal support, and to 

 which a sort of skin will be 

 formed of the gelatine, and 

 we have before us the Sea 

 Mushroom. The calcareous 

 axis of these animals, from 

 the Southern Ocean, is cir- 

 cular, or oval, formed of UPPER SURFACE or THE SEA MUSH- 

 thin vertical plates, radi- ROOM. FUNGIA ACTINIFORMIS. 

 ating from a common centre. Over the whole of 

 this is spread the living gelatine, which dips into the 

 intervals between every plate, and covers these also. 

 The mouth is oval, and placed in the centre of the 

 disc, surrounded with tubercles ; and over the whole 

 of the upper surface are distributed hollow tentacles, 

 or arms, not unlike a number of minute leeches, which 

 seize and direct to the mouth the minute animals on 

 which this polyp feeds. When these animals are 

 roughly touched, or irritated, the arms are with- 

 drawn between the thin plates, and the flesh shrinks 



