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<!Dmttn) of Natural ^ 



beaver in many respects, though of a smaller 

 size. Its head is large and depressed ; ears 

 small and rounded; muzzle pointed, with 

 long stiff whiskers. Its hind feet are webbed, 

 and its habits are aquatic ; it swims with 



great ease, lives in the vicinity of water, and 

 burrows in the ground. Its tail is round, 

 instead of being flattened like the beaver, 

 and its scaly covering is partly concealed 

 by scattered hairs. It is easily domesticated, 

 and its manners in captivity are very mild. 

 The Coypti has two kinds of fur : long ruddy 

 hair, which gives the tone of colour ; and a 

 brownish ash-coloured fur at its base, which, 

 like that of the beaver, is used largely in 

 the manufacture of hats. It is believed that 

 about 800,000 skins of this animal, under the 

 name of Neutria skins, have sometimes been 

 imported into Britain from South America 

 in the course of a year. There is, or was 

 lately, in the gardens of the Zoological So- 

 ciety, a live specimen of this water-loving 

 creature, which enjoyed itself much by 

 diving, while the ease and grace of its man- 

 ners could not but gratify the visitors. 



CRAB. (Cancer.) The name of a con- 

 siderable group of invertebrate animals, 

 I whose bodies are covered by an external 

 skeleton, or calcareous crust, having ten 

 articulated limbs, adapted for swimming or 

 walking, and breathing by gills. The head 

 and corselet are united, the latter being 

 broader than it is long : the tail is short in 

 proportion, and concealed by being turned 

 forward beneath the body. They belong to 

 the section of ten-legged, short-tailed Crus- 

 tacea (Decapoda brachyura) of the latest 

 systems, and are of numerous species, ex- 

 ceedingly various in size, colour, and modes 

 of living. The sense of sight, in most of the 

 species, is peculiarly acute, and enables them 

 to distinguish the approach of objects from 

 a very considerable distance. But they are 

 mostly remarkable for a complex and ela- 

 borate apparatus for mastication. The mouth 

 is furnished with at least eight pieces or 

 pairs of jaws, which pass the food through 

 an extremely short gullet into a membranous 

 stomach of considerable size. This stomach 

 is rendered curious by having within certain 

 cartilaginous appendages, to which strong 

 grinding teeth are attached. These are five 

 in number, and placed at the pyloric ex- 

 tremity, or outlet of the stomach, so that the 

 aliment, after being subjected to the action 

 of the jaws, is again more perfectly chewed 

 by the stomach-teeth, before entering the 



digestive tube, where it is exposed to the 

 action of the biliary fluid of the liver. The 

 latter organ is of great size in these creatures, 

 and is all that soft, rich, yellow substance, 

 found immediately beneath the superior 

 shell, called the fat of the Crab. A little 

 posterior to the stomach (commonly called 

 sand-bag), the heart is situated, a some- 

 what globular, whitish body, which propels 

 a colourless lymph to the gills (called mad 

 men's fingers) and rest of the body, whence 

 it is brought back to the heart by a hollow 

 vein (vena cava) of considerable size. 



The process of sloughing, moulting, or 

 throwing off the entire calcareous covering 

 which constitutes their only skeleton, ia 

 common to all the Crustacea, and is very 

 worthy of attention. As it is obvious that 

 the hard shell, when once perfected, cannot 

 change with the growth of the animal, it 

 becomes necessary that it should be shed 

 entirely ; and this shedding takes place at 

 regular periods, at which the increase of 

 size occurs. No one can behold the huge 

 : claws or forceps of various species, and the 

 ! smallncss of the joints between them and 

 ; the body, without feeling some surprise that 

 : the creature should be able to extricate them 

 j from the old shell, though this is readily 

 accomplished. The aquatic Crabs, when 

 the season of shedding arrives, generally 

 seek the sandy shores of creeks and rivers, 

 and, having selected a situation, they remain 

 at rest, and the change begins. The body 

 of the Crab seems to swell, the large upper 

 shell is gradually detached at the edge, 

 or where it joins the thorax or corselet, 

 and the membrane gradually gives way, 

 and rises up from behind, somewhat like the 

 lid of a chest. The Crab next begins to 

 withdraw the limbs from their cases, and 

 the large muscles of the claws undergo a 

 softening, which allows of their being drawn 

 through the smaller joints. This movement 

 is slowly effected, and, at the time it is ac- 

 complished, the parts about the mouth, the 

 antennae, and eyes, are withdrawn from their 

 old cases, and the animal escapes, retaining 

 its original figure, but soft, helpless, and 

 incapable of exertion or resistance. By a 

 gentle and not very obvious motion, we 

 next observe the sand displaced below the 

 body, and the Crab begins to be covered with 

 it, until, at length, he is sufficiently covered 

 for safety, though still in sight. This is 

 generally in shallow water, where the sun 

 shines freely upon the bottom ; and, in 

 the course of twelve hours, the external 

 membrane begins to harden, so as to crackle 

 like paper when pressed upon, and the 

 process of hardening goes on so rapidly, that, 

 by the end of the next forty-eight hours, 

 the Crab regains something of his former 

 solidity and ability to protect himself by 

 flight or resistance. 



The habits of Crabs are very various : 

 some are exclusively aquatic, and remain 

 on the sands or rocks, at great depths in the 

 sea ; others inhabit excavations formed in 

 the soft coral reefs or bars on certain coasts ; 

 some spend their days altogether on shore, 

 living in burrows or dens, formed in a moist 

 or boggy soil ; others resort to the rocky flats 



