The Mighty Deep 



struction. Crabs and Lobsters wear strong suits 

 of sheltering armour, joined together bit by bit, 

 as knights and squires of old were clothed from 

 head to foot in the many '' pieces " of a 

 mediaeval soldier's military suit. 



The armoured hosts belong to various divisions 

 in the Animal Kingdom, — starfishes and sea- 

 urchins to one ; limpets and oysters to another ; 

 crabs and lobsters to a third. And all three, 

 together with microscopic jelly - specks and 

 sponges and coral-polyps and medusae, belong 

 to a much greater Division, which embraces all 

 ''Invertebrate" or Backboneless creatures. 



If they have not backbones and ribs, they 

 have skeletons of a kind. Only, as a general 

 rule, the skeletons lie outside or are visible 

 through the transparent body, instead of being 

 hidden away inside, as in most fishes. 



The prickly-skinned starfishes and sea-urchins 

 are familiar objects with most of us. 



Both belong to a Division in the Animal 

 Kingdom which is well above the level of jelly- 

 fishes. Both have arms or rays, proceeding 

 from a central disc. But in the starfish the 

 rays are separated ; in the sea-urchin they are 

 joined together. 



Starfishes and sea-urchins are able to move 

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