112 UNIVALVES. 



palest towards the summit : size an inch long, 

 the breadth rather exceeds the length. 



This shell beautiful in its form and colour, is 

 still more interesting in its history, as displaying 

 another instance of the overruling care of the 

 Creator, and of his compensatory providence. 

 Unlike most fragile shells, its dwelling is the 

 stormy ocean ; but as the feeble reed bends to 

 the mighty wind, and rises unhurt when its 

 power is suspended, so this delicate shell offering 

 no resistance to the sea, rides upon its waves in 

 perfect safety ; and as if still more to diminish 

 its gravity, the shell has no solid columella. 

 It is always found floating upon the water, and 

 probably never visits the bottom, or willingly 

 approaches any shore. It is thus supported on 

 the surface, by means of a small cluster of 

 bubbles composed of transparent vesicles which 

 it can inflate with air at pleasure, and thus buoy 

 up its delicate bark. Every shell contains 

 about a teaspoonful of liquor of a most beautiful 

 red purple, which is easily discharged, as soon 

 as the animal is touched. It is said also to shine 

 by night with a phosphorescent light. This shell 

 had always been considered a Helix by Linneus 

 and others, until the time of Lamarck who 

 determined it to be necessary to place it in a 

 distinct genus. He ascertained that its inha- 

 bitant differed essentially from the snail. The 

 organ which in the snail is considered a foot, 

 was found not to be fit for crawling, but swim- 

 ming, being covered with the air bladders 



