314 IN LOiVER FLORIDA WILDS 



particularly during storms, breaks down the corals 

 and the fragments left are rolled and ground about 

 until they are reduced to sand and mud. The 

 dead portions of a coral reef are made up of the 

 most inconceivably rough and irregular rock mass 

 with fragments of every size and shape scattered 

 about. Among these fragments but chiefly under 

 them thousands of moUusks and other marine 

 animals take refuge and live in comparative safety, 

 for no enemy is likely to overturn the rocks which 

 shelter them. The crevices fairly swarm with 

 life, crabs, sea urchins, star fish, moUusks, worms, 

 anemones, hydroids, and a vast number of others. 

 Break open any old mass of coral and in all pro- 

 bability it will contain a number of boring mol- 

 lusks, — Botulas, Pholads, Lithophagus, Gastro- 

 chsenas and Saxicavas. 



In the sandy or muddy patches of an old reef 

 may generally be found great white Tellinas and 

 Codakias, Strombus, the graceful little Colum- 

 bellas, Marginellas, and other interesting and 

 beautiful moUusks in great variety, but all so 

 hidden in one way or another that only a close 

 search will discover them. There is a curious mol- 

 lusk an inch or more in length (Ultimus gibbosus) 



