"HIDDEN CITY" Calm and content nestled among the white sand and shells fragments on the ocean floor, this armored tough guy is the anchor for an entire underwater city. Who resides in this safe-haven? I accidentally stepped on a crab. He pinched the bottom of my foot. Startled, I jumped back and watched him scurry away with a stream of moss, algae and seaweed growing on his topside. He came back to his turf and graciously accepted a flower-peace offering gift from me.