SEA ANEMONES AND CORALS 



45 



and farther north. Large specimens are about three inches wide 

 and four high. When expanded the body is cylindrical with a 

 dense fringe of tapering tentacles surrounding the slit-like mouth. 

 The tentacles are covered with minute hair-shaped organs, or cilia, 

 which wave outward so as to create a current from the base toward 

 the tip of the tentacle, and they are also armed with thread cells 

 that sting the small creatures upon which the anemone feeds. 



These sea anemones develop from eggs, but they also slowly 

 divide ; an originally single anemone sometimes splitting longitu- 

 dinally until two are produced. In addition ilrs. M. L. Hammatt dis- 

 covered that little anemones are often budded out from the base of 

 large ones. 



The body of the anemone contains powerful muscles, and when 

 the animal is disturbed these contract so that the tentacles are rolled 

 inward and hidden away, while the body becomes a mere dome-like 



Fig. 21, ■ AVHITE-ARMED ANEMONE. Fiom Life. 

 Specimens in tlie New York Aquarium. 



mass. Long, white, thread-like filaments are also extruded through 

 pores in the sides of the body. These filaments (Fig. 20), are called 

 acontia, and bear great numbers of stinging thread-cells. 



The White -Armed Anemone, ( Sagartia lencolena, Fig. 21 J, is 

 common off the Long Island coast, and extends from the Carolinas 

 to Cape Cod. It is slender, the body being somewdiat more than 

 two inches long, while the tentacles are about one inch in length. 



