^C. sapidus^ (Mary J. Rathbun), ^C. hastatus^ (Stimpson), the blue crab. This is the common edible crab of the Atlantic coast. It is known at the North as the "blue crab," and at the South as the "sea-crab." It is found from Cape Cod to Florida, and after the lobster is the crustacean which has the greatest commercial value, being taken in immense quantities for the markets, not only when the shell is hard, but immediately after moulting, before the new shell has hardened, when it is known as the "soft-shelled crab." It inhabits muddy shores, and is common in bays and at the mouths of estuaries. The carapace is about twice as broad as it is long, and has a long, sharp spine on each side which projects outward. This is a distinguishing feature. There are eight short spines on each side between the long spines and the eyes; then come recesses for the eyes, and between the eyes are four unequal teeth and a small spine underneath. The chelæ are large and somewhat unequal in size; then come three pairs of simple feet and a fifth pair, which are flattened, forming swimming-organs. The margins of the carapace and abdomen are fringed with fine hairs, as are also most of the joints of the limbs. The upper surface of the body and claws is dark green in color, the lower surface is dingy white, the feet blue, and the tips of the spines reddish. The body is compressed, the carapace being moderately convex above, and is covered with minute granulations, which are more numerous over some portions than over others. The abdomen of the female is very broad and fills the entire space between the bases of the posterior pair of feet. During the spawning season it is so charged with eggs that often it projects out almost at right angles with the carapace. The [pg276] crabs of this species are very active and can swim rapidly. They also have the habit of pushing themselves backward into the mud for concealment. They are predaceous and pugnacious, and have great strength in their claws, which they use with dexterity. They not only fight their own kind, but show a bold front to all enemies, including man. The average size is six inches across the carapace. GENUS ^Ovalipes^ [Illustration: /Ovalipes ocellatus/, the lady-crab.]