674 THE LIVING ANIMALS OF THE WORLD 



have seen numbers of the little greenish SuORE-CRABS, running about on the sand, or over 

 seaweed-covered rocks, at low tide. These small crabs are harmless, but large I^inds are able 

 to give a very severe pinch. It is related that when the great chemist Sir Humphry Davy 

 was a boy he used to maintain that pain was no evil, until a large crab gripped his toe one 

 day when he was bathing, after which he changed his opinion. 



Some crabs are smooth and shining, but others are covered with bosses, excrescences, and 

 spines, which give them a very formidable appearance, and must be a useful protection against 

 any enemies to whose attacks they are exposed. In many species one of the two great claws 

 is always much larger than the other. Some have round bodies, others are oval or nearly 

 square ; some have short legs, and others very long ones. The species differ much in their 

 habits; and in tropical countries there are land-crabs which live entirely on shore, and others 

 which are amphibious, and climb cocoanut-trees to get at the nuts. As a general rule, 

 however, crabs are carnivorous and marine, and play the part of sea-scavengers. 



The King-crabs differ very much from any now living in the British seas, but 

 are generally considered to be allied to the Trilobites, an e.Ktinct family which appears to 



have been extremely 

 numerous in very ancient 

 seas. King-crabs are 2 

 or 3 feet long from the 

 front of the body to the 

 end of the tail. The 

 front part of the body 

 is entirely covered by a 

 curved oval shield, while 

 the hinder part of the 

 body is much narrower, 

 and armed at the sides 

 with strong teeth directed 

 backwards, and also with 

 a long and strong spear, 

 something like that of 

 a sword-fish on a small 

 scale, as long as the rest 

 of the bod}'. The few 

 species known exhibit an 

 instance of what is called 

 " discontinuous distribu- 

 tion," since they are found only on the coasts of the Moluccas, East Indies, and the 

 Southern United States and West Indies. 



SCORl'IONS, SriDERS, AND MiTKS 



These creatures form a peculiar group in which there are only two principal divisions of 

 the body, the head and thorax being fused into one mass, and the abdomen forming a separate 

 division. In the Mites, however, the body forms a single round or oval mass, even the division 

 between the thorax and the abdomen having disappeared. The members of the group have 

 no antcnn;e, but two pairs of jaws and a pair of palpi, frequently very long, and armed with 

 a pincer-likc arrangement at the end, in which case they are called " foot-jaws." Except in 

 some of the mites, which have only four or six, all the group have eight legs. They pass 

 through no metamorphosis, but moult several times after quitting the egg before attaining 

 their full growth. They have frequently several pairs of simple e\-es, but no compound eyes 

 like the large pair on the head of most insects. 



In the Scorpions, of which there is a considerable variety in different parts of the world, 



Phole hv IV. SjviU,^Kinl, F.Z.S. 



FIGHTING CRABS 



The mala an remarkable for haumg one large icarkt clazv, the other heiiiir rudimentary (the femalei 

 pOiiCiS tivo small claius only). The eyei also are seated at the end of lon^r stalks 



