RADIATES. 



177 



latter becoming a perfect creature, yet remaining adher- 

 ent to the original polyp. There thus result polyparies 

 or coral masses, masses consisting of distinct individ- 

 uals, living with a collective existence either by having 

 one common digestive tube or by vascular intercom- 

 munication. Some of these are quite soft, such as the 

 sea-anemones, so named on account of their variously- 



FIG. 105. 



A, Anemonia sulcata ; B, Cerianthus membranaceus ; C, Bunodes gemmaceus 

 (closed) ; D, the same (open). 



colored and numerous tentacles, that, when spread out, 

 resemble a flower in full bloom. However, in a large 

 number of these creatures the soft parts are sustained 

 by a hard calcareous skeleton, constituting the polypary 

 or coral. In the madrepores this skeleton is developed 

 in the form of a cup, whose walls carry radiating par- 



