78 SOLDIER-CRABS. 



Wo find in Italy, Greece, and Egypt, another species of land- 

 crab, which lives along the margins of rivulets, known to natura- 

 lists under the name of Tkelphu'sa Jluviati'lis. 



1. The decapods of the section of ANOMOU'RA differ from each 

 other widely in their organization. Although the abdomen or 

 tail ij not reduced to the rudimentary condition, as in the 

 Bra'chyu'ra, it does not afford them great assistance in swimming. 

 As their name imports, the Anomou'ra have tails of very unusual 

 conformation ; instead of being encased in a hard coat of mail, 

 as in the lobster, the hinder part of the body is soft and leathery. 

 This section includes many genera. 



8. The Soldier-crabs or Hermit-crabs (Pagurus) are remark- 

 able for their habits. They frequent sandy and level shores. 

 They always take possession of empty turbinated shells of some 

 gasteropod mollusk, in which they establish themselves, and we 

 may readily conceive of the reason of this habit : the abdomen, 

 instead of being hard and crusta'ceous, as in other animals of the 

 same class, is always soft and membranous ; therefore, to defend 

 it from the attacks of their enemies and to preserve it from 

 numerous accidents to which its softness exposes them, they need 

 a kind of armour, which they find in the shells in which they 

 lodge. When they have increased in size and find the dimen- 

 sions of their, dwelling too narrow, they take possession of a 

 more voluminous shell ; but, except for this purpose only, they 

 never go out of the shell entirely, but always carry about with 

 them their domicil, and on the approach of the smallest danger 

 retire into it. It is said, that if we remove from their shells a 

 number of these soldier-crabs, or pirates, as they are sometimes 

 called, and leave the party only one o^ two ol the same shells, 

 they will fiercely dispute possession. 



" The wonderful adaptation of all the limbs to a residence in 

 such a dwelling cannot fail to strike the most incurious observer. 

 The chelce, or large claws, differ remarkably in size ; so that 

 when the animal retires into its concealment, the smaller one 

 may be entirely withdrawn, while the larger closes and guards 

 the orifice. The two succeeding pairs of legs, unlike those of 

 the lobster, are of great size and strength ; and, instead of being 

 terminated by pincers, end in strong pointed levers, whereby the 

 animal can not only crawl, but drag after it its heavy habitation." 



9. The decapods of the section of MACROTJ'RA are recognised 

 nt first sight by the great development of their abdomen, which 

 always terminates in a large fin (Jig. 61, c), composed of five 



7. How is the section Anomou'ra distinguished ? 



8. What are hermit-crabs ? 



9. How is the section Macrou'ra distinguished ? 



