Abalone, a snail like creature that lives like limpets hugging the rocks and grazing on algae: upper left abalone from top, bottom left, abalone from below, the part that grabs the rock, a muscular 'foot'. Upper right: sea urchin (purple spines, from below, note mouth in middle), lower right, a giant keyhole limpet with fleshy foot partly covering the shell. Lower middle, this is a sea slug from below.