THE OPEN SEA 73 



Foraminifers float in the surface-waters, and 

 this is true of most of the very beautiful Radio- 

 larians, which have usually shells of flint, and 

 have established an internal partnership with 

 microscopic Algae. Perhaps it is this partner- 

 ship that has made them so successful, 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 contracting 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 



