SAND DUNES AND SALT MARSHES 



Another member of this group of eeMno- 

 derms is the sand-dollar, which delights in 

 sandy bottoms and is found at and below low- 

 water mark on the outer beach. Like the rock 

 crab it burrows in the sand, but reveals its 

 presence there by a slight circular elevation 

 of the beach. In life it is covered with short 

 spines, which give it a brown color, but to 

 most persons its bleached and spineless cases 

 thrown up on the upper beach are more fa- 

 miliar. 



The more distinctly five-rayed members of 

 this family, the starfishes, are in places abun- 

 dantly represented on these shores below low 

 water by the common starfish and by the 

 Forbes' starfish. The latter resembles the 

 common kind very closely but is easily dis- 

 tinguished from it by its light orange madre- 

 poric plate— the porous stony plate through 

 which the sea water enters the wonderful sys- 

 tem of canals that end in the innumerable 

 foot tubes by which the animal drags itself 

 along. Starfishes are ravenous creatures, and 

 have a habit of protruding part of their stom- 

 achs and sucking in their prey. They are 

 much disliked by oyster men, who, it is said, 

 used formerly to cut up any starfishes thej^ 



260 



