190 



THE OPAL SEA 



Living 

 ribbons and 

 necklaces. 



Sea 

 urchins. 



Armor of 

 the sea 

 urchins. 



Star fishes. 



bands and borders with pale fringes, balls and 

 domes of blue with violet streamers — quite as 

 beautiful in their way. All of them are merely 

 jelly fishes, cousins of the more common unfor- 

 tunate that we find stranded on the beach after 

 a storm. 



On the sand beside the jelly fish are often 

 found stray members of the branch Echlnoder- 

 mata. The round sea urchin with calcareous 

 plated shell, armed with spines, and looking 

 like a chestnut burr in all save color, is one of 

 the best known of the family. Why he should 

 be so peculiarly well-defended with armor and 

 several thousand spines, is hard to discover. 

 To escape trouble he burrows and hides in the 

 sand, and has even the power of making pockets 

 in the solid rock, where he lies protected from 

 the motion of waves and the attacks of the 

 enemy. He moves about by the aid of hia 

 spines and tentacles, eats anything he can find, 

 and seems proof against being eaten; but no 

 doubt he has an enemy that circumvents him 

 sooner or later. 



Almost any pool or rock basin along the coast 

 will contain the five-pointed star fish which 

 with the sea urchin is classed among the echi- 

 noderms. It has tentacles with sucker feet 

 whereby it not only clings and walks but 



