DISTRIBUTION OF THE ACALEPELE. 



131 



wind on the thin transparent crest, which rises vertically along 

 the back and catches the moving breeze. The disk from which 

 the tentacles hang, and the 

 crest, are supported internally 

 by a calcareous plate contain- 

 ing numerous cells filled with 

 air, which renders the whole 

 animal so buoyant that it 

 floats on the surface of the 

 water and is wafted along by 

 the winds. 



The importance of the acale- 

 phse in the economy of the ocean 

 corresponds with their vast 

 numbers and their wide geogra- 

 phical range ; for though many 

 are confined to the waters of 

 the torrid zone, yet even the seas of Spitzbergen have been found 

 scintillating with vast shoals of the cydippe. They supply in a 

 great measure the food of the whale, and, converted into blub- 

 ber, attract the bold mariner to the Arctic seas ; innumerable 

 molluscs and crustaceans prey upon their inexhaustible legions, 

 and are in their turn devoured by the herrings, whose capture 

 is a source of abundance to whole nations of fishermen. Who 

 can count the millions which every moment destroys, and who 

 can think without admiration of those prodigal sources of life 

 which constantly fill up the void, and maintain their hosts 

 from age to age ? 



Velella Septen.trion.alis. 



K 2 



