THE FISHES, MOI.LUSCA, AND OTHEK OBJECTS. 65 



Jnwsr than that of the 

 mollusca, to which 

 they are in many 

 respects related. In 

 Fig 57 is a colony of 

 these creatures, at- 

 tached to the stern 

 of the common water 

 crow-foot, as seen by 

 an ordinary pocket- 

 lens. The mouth is 

 surrounded by nume- 

 rous tentacles, which 

 sweep the water ac- 

 tively in search of 

 food. The organ 

 bearing these is tech- 

 nically called the 

 lophophore, or "crest- 

 bearer," and it is 

 generally of a horse- 

 shoe shape. It is 

 difficult to give an 

 adequate idea of this 

 beautiful object by 

 means of a woodcut. 

 The play of the cilia, 

 the whirl of particles 

 towards the mouth, 

 together with the 

 ever - shifting and 



Fig. 57. 



Group of Plumatella. 

 



