112 UNIVALVES. 



violet, 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 

 a striking instance of the overruling care of the 

 Creator, and of his compensatory providence. 

 Unlike most fragile shells, its dwelling is in 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 re- 

 sistance to the sea, rides upon its waves in per- 

 fect safety. It is always found floating upon the 

 water, and probably never visits the bottom, or 

 willingly approaches any shore. It is thus sup- 

 ported on the surface, by means of a small clus- 

 ter of bubbles composed of transparent vesicles 

 which it can inflate with air at pleasure, and thus 

 buoy up its delicate bark ; the gravity of the 

 shell is diminished by its not having a solid colu- 

 mella. 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 phospho- 

 rescent light. This shell had always been consi- 

 dered a Helix by Linneus and others, until the 

 time of Lamarck who determined from its peculia- 

 rities to place it in a distinct genus. He ascertained 

 that its inhabitant differed essentially, from the 

 snail. The organ which in the snail is considered 

 a foot, in the lanthina was found not to be fit for 

 crawling, but swimming, being covered with the air 



