He does not trouble them. Out in the sea, Mr. Crab finds some small shell-fish called limpets. He likes them so much that he lets them live on his shell. They take fast hold on his back, and he does not pull them off. LESSON VII. SOME OTHER CRABS.[3] All crabs are not alike. There are many kinds. They differ in shape, color, and habits. Some are not at all pretty. Some are very pretty. All are very queer. The Spider Crab[4] has long, thin legs. The front of his shell, which is over his head, is not wide, but is a sharp point. This is to help him dig his way into sand and mud. Some crabs do not make a house in the sand; they live in holes in the rocks. The Horse-Shoe Crab is of a chestnut color. Some call him the King Crab. Look at his picture.[5] His shell is of the shape of the hoof of a horse, but it has a long tail, with sharp points on the edges. The tail is as hard as wood, and has edges like a file. The Horse-Shoe Crab lives in sand and in mud. He chooses the muddy banks where rivers or streams run into the sea. He pushes his way in the mud, with his big, round shell, and scrapes the mud out with his many feet. He eats the worms he finds in the sand and mud. Why are the worms down there? Like Mr. Crab, they build a house in the mud. Some time I will tell you about these worms. Now and then, as Mr. Crab goes along under the ground, he finds in his way a long, soft thing that looks good to eat. It is the long pipe or tube with which a clam takes his food. The King Crab puts out his claw to get it. The King Crab can move his hand claw as quickly as your cat can jump or strike out her paw. But the clam is far more quick than the King Crab, and shuts his shell down on the King Crab’s claw. Now is he held fast, like a rat in a trap! He waits to see if the clam will let go. No, he will not. Then the crab drops off his claw, and goes away to hide and grow a new one. Do you see, in the picture, a crab in a shell made like a curl?[6] That crab steals his house. He finds an empty shell, and goes into it to live. It is odd to see him run, with the shell he stole on his back. How does he live? By fishing. All crabs hunt and fish. I have told you how they hunt on the sand for bugs and flies. Did I not tell you how they hunt for grubs and worms under ground? How do they fish? Mr. Crab gets into a good place to fish. He pops out his eyes to see all about him. Then when things that he likes to eat float by, he strikes out with his big hand. He catches what he wants nearly every time. Crabs are very greedy. FOOTNOTES: [3] See Frontispiece. [4] See Picture in Lesson IV. [5] See Frontispiece. [6] See Frontispiece. LESSON VIII. THE HERMIT CRAB. [Illustration: HE COMES OUT TO DIE.] Do you wish to hear more about the crab that steals his house? Why does he do that? His back is long and soft, and has no hard shell. If he could find no hard cover, he could not live.