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HANDBOOK OF INVERTEBRATE ZOOLOGY. 



VI. The swimming larva of the starfish. 



The larvae of starfish, which are known as Bipinnaria and 

 Brachiolaria, are constructed on essentially the same plan 

 as the pluteus of the sea-urchin, although there are great 



Fig. 76. 

 Fig. 76. — The sea-urchin, with the arms of the pluteus disappearing. 

 (Drawn from nature by Mr. B. F. Colton. ) 



difierences in details of structure. They may usually be 

 obtained at the surface of the ocean in early summer with 



