AND STAB-FISH. 157 



by Cuvier under the sub-kingdom of " Kadiata ;" and 

 we still hear these spoken of as " radiate " animals, 

 a term we can readily understand if we take the 

 common star-fish as a type. But modern science 

 has rearranged the animal kingdom, and learned to 

 look more deeply than at superficial resemblances 

 for their true relationships. Hence the name of 

 "Annuloida" is now given to the star-fishes, sea- 

 urchins, and sea-cucumbers (Holotliuria). 



To look at the seemingly inert star-fish, or the 

 bristly sea-urchin, whose appearance has evidently 

 given to it its common name, on account of its 

 resemblance to the Hedgehog, one would never 

 dream of the marvellous hydraulic machinery by 

 means of which they are enabled to move about, any 

 more than we should imagine them to be fhe terribly 

 carnivorous creatures they are. We will take one of 

 the spiny sea-urchins first such an one as you may 

 obtain from the trawl-boat, or as you may chance to 

 find yourself underneath the stones, as Echinus 

 miliaris. The spines render them as difficult to 

 handle as their terrestrial namesakes are for dogs to 

 worry. But if you drop it in fresh-water, the 

 creature soon dies, and you then find that the spines? 

 and the membranaceous skin at their bases, will 

 peel off, leaving a tubercled shell beneath, which is 

 very pretty to look at. Each one of these rounded 

 tubercles acted as a joint, to which the cup-shaped 

 hollow of each spine was attached, thus giving each 

 spine the utmost freedom of motion. The shell, or 



