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Echiuoderius or Sea-urchin*. 



To this class belong sea-urchins, starfish, seacucumbers and 

 sea-lilies. It is saying very little when we call them interesting 

 and remarkable, all animals are so, even the sparrow and the 

 common fly, but one must be possessed of various and correct 

 knowledge in order to find it out. The Echinoderms however, are 

 doubly interesting to people who live at a distance from the 

 sea, for nothing like them is to be found either on land or in 

 sweet water; they are entirely novel creatures , true children 

 of the ocean. But this is not the most interesting fact concerning 

 them. 



Another peculiarity distinguishes the Echinoderms from all 

 wellknown land and sweet-water animals. It is true that these 

 land creatures are as mysterious and inaccessible to the unlear- 

 ned, as far as concerns their organisation, as any marine snail, 

 medusa or sea-urchin. But on the whole, the unlearned know 

 that all birds, fish and insects can boast of a head, legs, gills 

 or wings, eyes, mouth and many other visible organs. 



But what must we think of a sea-urchin or starfish? These 

 creatures live, therefore they must eat; but where is their mouth? 

 Where are the members with which they seize their food? They 

 live in the sea, -but how do they move? Do they swim or creep? 

 Can they see and hear ? 



The unlearned cannot answer these questions, and will be 

 grateful, if, without superfluous science, this little book tries 

 to explain the essential properties of the Echinoderms. 



First of all , we beg our reader to put out of his head all 

 such things as heads and tails, arms and legs, gills and wings; 

 and to be sure that the Echinoderms can do without these mem- 

 bers quite as well as the corals or medusae. But the Echino- 

 derms have a much more complicated organisation than any 

 of these last - named creatures. 



It is only lately that we have become acquainted with the 

 anatomy of the Echinus and, as usual, the better it is known 

 the more interesting the object becomes. 



The outer forms of the Echinoderms vary greatly, Some are 

 as round as a ball, others flat as a leaf; others again are like a 

 star or a sausage , or , to use a more refined comparison, a 

 cylinder; and finally, some have a stem like a flower and see- 

 mingly a calyx and leaves. The shell or skin of these animals 

 looks like mosaic. It consists of a great number of differently 



