A close-up look at sand urchins and rock urchins. At the seashore, a man digs up a sand urchin. We look closely. He sets it back in the sand, and it burrows out of sight. Its intestines ...
A close-up look at sand urchins and rock urchins. At the seashore, a man digs up a sand urchin. We look closely. He sets it back in the sand, and it burrows out of sight. Its intestines ...
