SEAWORMS, SEAWEEDS, AND OTHER SEA-THINGS. 141 



This shell consists of five side-pieces which 

 are grown together, and a pair of movable ones at 

 the top, resembling a duck's beak. When the 

 creature is under water, it opens this beak, and 

 throws out a scoop-net to gather food. It is very 

 interesting to watch this curious motion. 



Another barnacle has no side-pieces, but its 

 beak is attached to a long fleshy stem, which it- 



Figure 83. 



self is attached at one end to a rock or a piece of 

 floating wood. Great numbers of them may be 

 seen clinging to the wharves, along with mussels 

 and seaworms. 



Some barnacles seem anxious to get a free ride. 

 They will select the back of a crab or the bottom 

 of a ship, while one kind is very partial to the 

 skin of a whale. 



The crab carries his barnacles about till he 



