492 



THE OCEAN WORLD. 



constitute each antennae a semi-tube, so that when the pair were 

 brought face to face the tube was complete." 



Among the numerous genera of Bracliyurous Crustaceans, Grapsus 

 is distinguished by its less regularly quadrilateral form ; the body 

 nearly always compressed, and the sternal plastron but little or not at 

 all curved backwards ; the front strongly recurved, or, rather, bent 

 downwards ; the orbits oval-shaped and of moderate size ; the lateral 

 edges of the carapace slightly curving and trenchant ; the ocular 

 pedicles large, but short : their insertion beneath the front and the 

 cornea occupies one-half of their length. 



Fig. 337. Pagurus Bernhardus. 1, out of the shell ; a, right jaw-foot ; 6, in the shell. 



The Hermit or Soldier Crab (Pagurus 'Bernhardus, Fabricius, 

 Fig. 337) is, perhaps, the oddest and most curious of Crustaceans. It 

 differs from most other Crustaceans in this : in place of having the body 

 protected by a calcareous armour, more or less thick and solid, it has 



