SEA LIFE 51 



as opercula, "with which they close their houses from 

 their enemies. Many of them are polished, and used 

 as jewelry in the fashionable world. Echinoderms, 

 or sea-urchins, of gigantic size adhered to the rocks, 



HALIOTIS. 



where, by working their spines, they had worn away 

 cavities large enough to hold their bodies. Oysters 

 grew on the rocks in great masses ; and although I had 

 never eaten one before, I soon learned to eat and like 

 them. We would crack them open with stones, fill tin 

 cans, and cook them over a small fire on the beach. 

 There was a large pearly shell known by the name of 



