LEN6THWI5£ 

 5ECTION 



CROSS 

 SECTION 



SIMPLE 

 ANEnONE 



SIMPLE 

 CORAL POLYP 



Figure 10. Lenqtnv/ise and cross sections of a simple anemone and a 

 simple coral. The mesenteric folds of the body wall which project into 

 the interior are omitted for the sake of clarity. Dark portion represents 

 stony skeleton. 



folds was originally part of the outside of the polyp and 

 it continues to secrete the limestone deposit. In this way 

 it forms radial stony partitions projecting from the 

 wall of the coral cup inwards towards the columella. In 

 some corals there is little development beyond this stage, 

 and the polyp merely forms a single cup with radiating 

 plates or septa inside it. Most corals, however, develop 

 by growth in size and complexity of the individual polyp 

 or by the branching and multiplication of polyps. 



43 



