Most of the north end of Brigantine  Island, New Jersey is a natural area, part of the Forsythe National Wildlife Refuge.   I often enjoy walking along the beach there.  One fall morning at low tide I came upon this colony of tiny shellfish in a pool left by the receding water.  I had often watched the Sanderlings and Dunlins feeding in these pools but had never before seen the shells under water, each of them less than half an inch long.