shells are treasures of the sea left on the shore

admiration beach beautiful beauty bivalvia calcium cephalopoda chitons clams collection conflicting crab creatures detritus discourage discouraged edge gastropoda hard hermit limpets monoplacophora mussles myriad nature nautilus objects ocean octopus oysters pearly polyplacophora sand sandy scaphopoda seashell shapes share shell shells slugs snails spiny squid starfish tough treasure tusk varient variety water