286 C O N C H O L O G Y. 



lea, to ferve as a rudder ; and thefe up- 

 hold the Ikin, or membrane, which he ufes 

 for a fail to ply the wind. Thus equipped, 

 he navigates in calm weather ; when fear- 

 ful of danger, he retires within the Shell, 

 by which aftion it gains water, and finks 

 to the bottom. He often pumps the wa- 

 ter out, and alfo often quits the Shell, 

 which, floating empty, is carried by the 

 waves, and daihed to pieces on the rocks. 



The fifh quits the fhell at pleafure, for 

 he is not attached to it by any part of its 

 body. Frequently he turns himfelf and 

 ihell topfy-turvy, and rifes with his head 

 downwards from the bottom of the fea, 

 and, when he has gained the furface of the 

 water, turns his fhell very nimbly empties 

 the water in it, extends his arms, and fets 

 fail. They are frequently found without 

 their Shells^ and the fifliermen muft even 

 be extremely expert to catch them in it*. 



The 



* I much fufpe^l this account ; but I cannot deny it 

 to be true, though I know not of any animaU, that 



have 



