ANIM ALS WITH JOINTED LEGS— THE ARTHROPODS ^97 



14. What characteristic gives cyclops its name? 



15. How does the hermit crab secure protection from its enemies? 



16. What is the importance of autotomy in crustaceans? 



17. Compare regeneration of the crayfish with that of some of the other animals 

 we have studied. 



18. Describe a compound eye. 



19. How are water fleas economically important? 



20. When a female crayfish has eggs on her swimmerets she will wave them 

 back and forth continuously. What is accomplished by this action? 



