[AS.] A shell-fish with strong claws, and a tail tucked underneath its body. The eyes of crabs are on long stalks, and may be turned about or folded back into little grooves in the shell. Crabs breathe by gills, and a crab's heart consists of a single sac. They shed their shells at intervals, and while the new shell is growing is known as soft-shell crabs. These are esteemed as food in the United States. In the tropics some species of crabs live in the fresh water of the rivers; others in the damp forests, visiting the sea-shore to deposit their eggs ; others, like the land-crabs of Jamaica, live on the mountain tops. The hermit crab is a curious animal without a shell for its soft body ; so it seeks to shelter its body in some empty shell, and when it outgrows one shell hunts for a larger one, sometimes turning out the living owner of a shell it wishes. The fiddler crab has one claw much larger than the other,developed by fighting, which it holds up as it walks cideways. The females of the pea crabs, or oyster crabs, live in oyster shells, and go out and in at will. Horse-shoe crabs, or king crabs, the largest crabs, are dark brown, and have long, stiff tails.