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ELEMENTARY ZOOLOGY 



radiating arms are long, slender, sometimes repeatedly 

 branched, and all the branches bear fine lateral projec- 

 tions called pinnulae. Most of the feather-stars live in 

 deep water and are thus only seen after being dredged 

 up. They feed on small crab-like animals, and on the 

 marine unicellular animals and plants. 



FIG. 24. A crinoid or feather-star, Pentacrinus sp. (After Brehm.) 



