Once upon a time that name was equally common. Everything that had its home in the sea was popularly supposed to be a fish. We know now that not one of the above belongs to any Fish tribe; yet in Conservative style we keep the old titles going.
Crabs and Lobsters, Shrimps and Prawns, are members of the vast Crustacean division or family. They are so called on account of the hard protecting crust, or armour, by which their soft bodies are guarded. Chief and foremost among the numberless kinds included under this head is the busy vigorous sidling Crab.
And very important animals are crabs, in the economy of the Ocean. Not only from their enormous numbers; not only from the wide extents of land and sea which own to their presence; not only from the fact that they form a principal item of food to fishes and even to whales; but also because at least one species is reckoned excellent eating for man.
There are land-crabs as well as sea-crabs. There are deep-sea crabs, as well as shallow-water and shore crabs.
A DEEP-SEA CRAB
The holes in front are for the admission of water containing nutritious animal food
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There are crabs much less than half-an-inch across; and there are giant Japanese crabs, carrying heavy back-armour or “carapace,” about a foot in length and breadth, while the sprawling limbs extend to a yard and a half or more on either side.
Those of ordinary sizes are found everywhere; in numbers beyond reckoning. Not only in tropic waters, but in moderate climes, and in frigid zones; alike near the poles and under the equator. Different species, of course, in different parts, but all connected.