Near me on the right the sand disappeared under a bed of dark ooze; for here was the mouth of an inlet, and twice each day the tide hurrying back through its intricacies brought black mud from the marshes to deposit upon the beach. In this layer of pasty soil I presently discovered a track very like what we call “ladder footprints” in fossils. There were numerous holes as if made by some slim, sharp instrument, and on each side a furrow. I rose and traced this track until it disappeared under a fresh deposit of mud. As I turned seaward again I saw at the edge of the water a dark-brown shining object over a foot in diameter, with rounded front and convex surface, moving laboriously along the slime. After it had travelled some yards from the water to a place where the mud-bank overlaid the sand by two or three feet, the creature came to a pause and presently began to disappear. The large, rounded shield entered plow-like into the mud-bank, sank lower and lower, and then the triangular hinder shield vanished, and finally the long spiked tail. This animal was a limulus, or horseshoe crab, and he was now plowing his way about in the mud, seeking for his dinner. The previous day the tide had been very high, and I knew that in the high tides of June the female limulus comes up to lay her eggs on the margin of the sand. I further reflected that numerous boulders and small sharp rocks were strewn along this coast, and that the high tide had been accompanied by a violent wind. From these facts I concluded that I might find a dead limulus among the rubbish at high-water mark. At the summit of the beach was a long swath of sea-weed, empty and broken shells, bits of wood, and the flotsam that is cast up by the sea. All this débris was dry atop, but thoroughly wet a few inches below the surface, and there “beach fleas” were hopping actively, and scallop shells lay tightly closed, and certain hapless crustaceans were on their backs entangled. Being sorry for these poor creatures, likely to die long before the lagging tide returned for them, I spent some minutes in flinging back into the water the scallops and crabs which had been cast out. As I pursued these benevolent labors, I saw in the wreck heap, the long, spiked, serrated tail indicating a limulus, or horseshoe, or king crab. Removing the rubbish I disentombed a limulus, full twenty inches across the widest part of the shield, and that shield so hard and thick and dark, that it resembled a piece of sheet iron rather than a portion of an animal. But hard as it was, some wave flinging it upon a sharp rock had wrought its destruction, and a large break on one side told how Madame Limulus had perished. The animal was remarkably heavy, but dragging it to my rock, I made it the theme of my meditation.