MANUAL OF NATURAL HISTORY. 281 



turn pursued by the Climbing-Perch (Anahas testu- 

 dineus) ; thus we have both Crabs and Fishes climb- 

 ing up terrestrial Palm-trees. Some Crustaceans 

 attain a large size when compared with the Insect 

 tribes, the Thorny-Lobster (Palinurus vulgaris) 

 being sometimes nearly three feet in length. The 

 common Lobster (Astacus gammarus) is an especial 

 favourite among epicures, and is easily recognized by 

 its enormous claws. The tribes of Crustacea change 

 their skins or moult regularly, while among insects 

 this takes place only in the larval state ; but in 

 these animals, which continue to grow all their lives, 

 the changing of their coats occurs at regular inter- 

 vals. They have the singular power, moreover, of 

 replacing a lost or mutilated limb by growing 

 another, which reconciles them to parting with their 

 legs when seized by their enemies. Some among 

 them are enabled to leap about, like the Sand- 

 hoppers (Gammavidce), while the extinct tribe of 

 Trilobites possessed the faculty of rolling themselves 

 up in a ball like the Wood-lice of the present epoch. 

 The members of the great Entomostracous group, 

 which are covered with a thin horny skin, are ex- 

 tremely varied in their external form ; some have 

 suctorial mouths, and live parasitic on other animals ; 

 others masticate their food by means of horny jaws ; 

 while some, as the King-Crabs, employ the dilated 

 coxse of the six anterior pairs of legs for the same 

 purpose ; thus these animals may be said to eat with 

 their legs. Some of them, as the Cypris, are enclosed 

 in a bivalve shell, and represent the Mollusca ; 

 others, again, approximate the Arachnidans, as the 



