THE OPEN SEA 73 



Foraminifers float in the surface-waters, and 

 this is true of most of the very beautiful 

 Radiolarians, which have usually shells of 

 flint, and have established an internal partner- 

 ship with microscopic Algae. Perhaps it is 

 this partnership that has made them so suc- 

 cessful, for there are 5000 different kinds, and 

 the number of individuals is past all telling. 



The Stinging Animals are represented by 

 swimming-bells, most of which are budded 

 off from shallow-water zoophytes; by true 

 jelly-fishes or Medusae, rhythmically contract- 

 ing and expanding their translucent discs; by 

 strange colonies like the Portuguese-Man-of- 

 War; and by the delicate Ctenophores. One 

 of these called Venus's girdle, like a ribbon of 

 flexible glass, iridescent and phosphorescent, 

 is one of the most beautiful animals of the sea. 



There are not a few open-sea worms, some 

 of them, like the Arrow-worm, quite trans- 

 parent; and there are actually a few sea- 

 cucumbers which have departed widely from 

 the sluggish habit of their shallow-water and 

 deep-water relatives. 



Jointed-footed Animals are represented by 

 many kinds of Crustaceans, from gorgeous 

 prawns to pinhead-like "water-fleas"; and 



