ox CRUSTACEA. 275 



brachyuri are rather runners than swimmers, and suffer 

 themselves to proceed at the will of the waves, assisting them- 

 selves in a trifling degree with their feet. They usually walk 

 sideways, or backwards, and run with a velocity equalling 

 or surpassing that of a horse, gaining, on the slightest ap- 

 pearance of danger, their habitual retreats, or any which 

 chance may happen to present. They pinch strongly with 

 their claws or forceps, and sometimes sacrifice them by leav- 

 ing them within the hands of the person by whom they have 

 been seized, that they may themselves escape. Nature re- 

 pairs this loss the more speedily, if the breach be made at 

 the joints, especially the second or third. 



The growth of the craw-fish is slow, and according to the 

 testimony of fishermen, it is hardly saleable at the end of 

 seven or eight years from its birth. Some Crustacea, such as 

 those which remain habitually at great depths, in inaccessible 

 situations, and which are better protected by the nature of 

 their testa, may attain to a very considerable age. It was 

 believed, in the time of Pliny, that some species could live 

 for a period exceeding the duration of the life of man. M. 

 Latreille has seen a great lobster ('palinurus) of nearly six 

 feet in length from one extremity of the body to the other, 

 whence we may infer its great age. 



The family of Brachyurous decapods is composed of the 

 genus Cancer or Crab. Under this name are commonly 

 designated all the Crustacea analogous to craw-fish, and 

 lobsters, but whose body is proportionally shorter and 

 broader, with a small tail refolded on the breast. In the 

 method of Linnaeus, the genus cancer has an acceptation 

 ■ much more general, since it comprehends the first three orders 

 of Crustacea, and even a part of the fourth. 



The crabs remain in preference on coasts where there are 

 rocks, in clefts where they are sheltered from the waves of 

 the sea, and secured from the pursuit of their enemies. 



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