Crab
Crab names 3 different subjects across the 6 encyclopedias on this shelf. Each is set out below. 1 of them is described by more than one encyclopedia.
Crab a popular name used to designate a large number of crustaceans--shellfish
Described by 2 of the 6 encyclopedias.
Aiton's Encyclopedia (1910)
a popular name used to designate a large number of crustaceans--shellfish. The crabs are to be distinguished from lobsters, crayfish, prawns, and shrimps by shortness of body. The abdomen or so-called tail of the body is reduced in size and is folded under the thorax, giving the body a broad, stout appearance. Crabs have stalk eyes and ten jointed legs. The front pair of legs is developed into large pincer-like claws. In the case of marine crabs one pair of legs takes the form of fin-like swimmerets. Crabs can scrabble over the sand in any direction, but they prefer to step sidewise. They have stout bodies covered with a firm shell, and look not unlike spiders in armor. There are many species not closely related. There are marine crabs and land crabs, swimming crabs and crawling crabs. There are large crabs and small crabs,--giant crabs, with arms so long that they open eighteen feet at the stretch, and peacrabs so small that they are able to live with the oyster in its shell. Some crabs live near the salt water; others live in it. Some species live on vegetable matter; other species, on snails, minnows, small shell-fish, and carrion. Anything fleshy, dead or alive, they crowd into the stomach with their pincers. The stomach is furnished with horny projections. It contracts and works like the gizzard of a chicken to crush and grind food. Crabs are great scavengers. At some seaside resorts they render service in keeping the shore clean. Shoals of them come up at night and act as scavengers. Crabs are of many colors, blue, red, purple, and green. Some are phosphorescent. The blue crab is esteemed for food, and may be found in the markets of seaside cities. It is taken by letting a bit of meat down into the water by a string. The crab seizes the meat with its pincers and holds on tenaciously until it is drawn to the surface, when it is an easy matter to take it with a landing net before it lets go. The sand crab has the color of sand, and hastens to bury itself to the eyes if a footstep approaches. Where a seashore was alive with them a moment before, nothing can be seen by the stranger, though many a pair of eyes are fixed upon him. The fiddler crab--not a true crab--fairly swarms along the shallow ditches of the Gulf States. It gets its name from one abnormally large pincer and one abortive one, suggesting a fiddle and a bow. The hermit crab, another distant relative, thrusts its soft tail into some empty shell for protection. The larger it grows the larger the shell it needs, a truth so impressed on the hermit that it squabbles with its neighbors constantly. A large hermit has been known to force a dozen other hermits to allow him to try on their shells, only to go back to his own as the best after all. The land crabs of the West Indies hide in holes in the daytime. At night they come out and pinch off the young shoots of the sugar-cane. They are so numerous that planters regard them as a serious pest. The largest crab known is the spider crab of Japan. Its scuttles about on the floor of the ocean 2,000 feet under water. It is said to have a spread of eighteen feet from claw to claw. See Crayfish Crabapple, a close relative of the apple. There are not less than seventy species. The crabapple has handsome leaves and beautiful fragrant flowers. The hawthorn of the English poets--the pride of English hedgerows--is a crabapple. The "crabs" or crabapples of our orchards are merely small, hardy kinds of apples adapted to northern latitudes, and brought, several of them at least, from Siberia. It would save confusion if we could use the English word hawthorn for our small fruited trees that are not apples. See Apple ; Hawthorn
Collier's New Encyclopedia (1921)
a popular name for all the 10footed, short-tailed crustaceans constituting the sub-order Brachyura, order Decapoda, comprising many genera, distinguished from the lobster and other macrurous or long-tailed decapods by the shortness of their tail, which is folded under the body. The mouth has several COYOTE pairs of strong jaws, in addition to which the stomach has its internal surface studded with hard projections for the purpose of grinding the food. The stomach is popularly called the "sandbag"; g"; a little behind it is the heart, which propels a colorless lymph (the bus Found America," "That Stanley," blood) to the gills ("dead man's fingers"). The liver is the soft, rich yellow substance, usually called the fat of the crab. They "moult" or throw off their calcareous covering periodically. The first pair of limbs are not used for locomotion, but are furnished with strong claws or pincers. Their eyes are compound, with hexagonal facets, and are pedunculated, elongated, and movable. Like most individuals of the class, they easily lose their claws, which are as readily renewed. The racer-crabs of the West Indies suck the juice of the sugarcane. Most inhabit the sea, others fresh water, some the land, only going to the sea to spawn. The common large edible crab (Cancer pagurus) is much sought after.
Crab a name given to various machines
Collier's New Encyclopedia (1921)
a name given to various machines, especially to a kind of portable windlass or machine for raising weights. Crabs are much used in building operations for raising stones and many other weights, and in loading and discharging vessels.
Crab A portable crane or winch
The Encyclopedia of Founding (1892)
A portable crane or winch, with gear-wheel on the barrel-shaft, in which a pinion is made to work by means of cranks at each end of the pinion-shaft. See CRAB; CRANE.
What Has Changed in the Last Century
The anatomy Aiton's set out in 1910 and Collier's in 1921 is still what a zoology class is taught: crabs are the short-tailed decapods (Brachyura), abdomen tucked under the thorax, first limbs made into pincers, stomach lined with grinding teeth. Two details have been corrected. The Japanese spider crab, which Aiton's said had "a spread of eighteen feet from claw to claw," tops out at about 12 feet (3.7 m) across the outstretched legs; and the fiddler crab, dismissed as "not a true crab," is a genuine brachyuran, while the hermit crab really is an outsider. Collier's "colorless lymph" is now known to carry hemocyanin, a copper-based pigment that turns the blood blue when it takes up oxygen — and the crab that reached those seaside markets on a baited string, the Chesapeake blue crab, is today a heavily regulated fishery with catch limits and stock surveys rather than an inexhaustible scavenger.
Written for this edition, 2026.