74 THE HAUNTS OF LIFE 



one must not forget the family of Open-Sea 

 Insects. 



Molluscs are represented by the Sea-Butter- 

 flies and other lightly built translucent Gas- 

 teropods, and by a number of active cuttle- 

 fishes, such as the Argonaut and some squids. 



Just across the border-line separating the 

 backboned from the backboneless animals is 

 the class of sea-squirts or Tunicates, and it is 

 interesting to find a few of these in the Open 

 Sea which do not degenerate as their shore- 

 relatives do, but keep up the promise of their 

 youth. Others form free-swimming colonies 

 like the brilliantly luminescent Fire-Flame, 

 sometimes as long as one's arm, and with a 

 light that one can read a few words by. Highly 

 fitted for open-sea life are the Salps, some- 

 times like single barrels of glass, two or three 

 inches long, sometimes in long chains, which 

 swim gently like glass-serpents in the sea. 



The rest of the roll is easy, the open-sea 

 fishes like the flying gurnard, some turtles and 

 sea-snakes, some birds like petrels and penguins, 

 and then the whales among Mammals. It is evi- 

 dent that the Open Sea has its share of variety. 



