MOLLUSC A OR UNIVALVES. 271 



versy had existed. She constructed a kind of 

 cage in the sea, near the coast of Messina, and 

 enclosed in it several of the living animals, 

 which she kept supplied with their natural food, 

 consisting of small molluscs. The result of her 

 observations went to prove that the animal is 

 in the habit of floating, or rather sailing, on the 

 surface of the water, using its dilated tentacula 

 as sails, the remainder as oars, and aiding its 

 movements by means of a kind of proboscis 

 which it employs as a helm : the animal is not 

 attached to the shell, but, when under water, it 

 adheres firmly to it by its sail-arms, which are 

 turned over and affixed to the outside, entirely 

 covering it. The shell, which is remarkably 

 brittle when exposed to the air, is perfectly 

 pliable in water, and is thus enabled to escape 

 the destruction which would otherwise appear 

 likely to be met with by so thin and tender a 

 fabric. 



The animal of the Argonauta, during life, and 

 when unconscious of being observed, is very 

 beautiful, the sails and other visible parts pre- 

 senting the most lively colours — purple, gold, 

 and silver. At the approach of any object, it 



