iated with corals and the rock is often encrusted with 

 brightly colored growths of seamats or Bryozoa. Cer- 

 tain barnacles, Creusia and Vyrgoma become attached 

 and as the coral grows around them they may become 

 entrapped so that they appear as gall-like swellings on 

 the rock surface, each with a small slit through which 

 the appendages of the barnacle project in search of food. 

 In a somewhat similar manner the gall crabs, Tlapalo- 

 carcinus and Cryptochirus become entombed in the 

 living coral. 



Superficially similar to the coral but really not too 

 closely related is the stinging coral, which grows into 

 small branches like miniature stagshorn or may form 

 encrustations on the surface of old coral or dead sea- 

 whips. The polyps are very small so that the skeleton 

 is easily distinguished from true coral by the lack of 

 visible cups. In their place the surface is covered by 

 fine barely visible holes, which account for the scien- 

 tific name, Millepora. The stinging cells of the false 

 coral are sufficiently powerful to develop an irritating 

 rash when handled with the bare fingers. 



A distinct contribution to the material of reef lime- 

 stone is made by the so called soft corals, often referred 

 to as seafans or seawhips. These brightly colored or- 

 ganisms are related to corals, although they differ in 

 many respects. The common seawhips, known as Vtero- 

 gorgia acerosa consist of long whip like branches the 

 surface of which is covered with small barely visible 

 polyps. The axis of each branch is a horny skeleton. 

 Embedded in the flesh surrounding it are numerous 

 small limestone spicules, which add to the coral sand 

 when the whip dies. Much thicker and heavier than 

 the seawhip, forming finger like branches or even thick 



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