THE CCELENTERATES AND SPONGES 137 



of new ones. Islands may be formed by the gradual accu- 

 mulation of the deposits of coral polyps, and even consider- 

 able parts of continents such as most of the peninsula 



FIG. 113. A group of sea anemones. (After Andres.) 



PlG. 114. A fringing reef with many varieties of corals. (After Saville- 



Kent.) 



of Florida. The red coral, much used in making orna- 

 ments, is derived from a species which occurs in the Medi- 

 terranean Sea. Some forms allied to the true coral 



