80 OCEAN LIFE* 



ECHINOIDEA. 



"THE Echini, however they may appear to differ in outward 

 form from the Asteridae, will be found to present so many points 

 of resemblance in their general structure, that the account we 

 have given above, of the organization of the last mentioned 

 family, will throw considerable light upon the still more elabo- 

 rately constructed animals which now present themselves to our 

 notice." 



" The Echini may be found in abundance upon our coasts, in- 

 habiting the sea, not far from the shore, or lurking among rocks, 

 where they obtain the means of sustenance. Their shape is more 

 or less completely globular, and their whole surface covered with 

 strong spines, on which they roll themselves from place to place, 

 moving them all as though they were stiff legs ; but if they wish 

 to hide themselves from observation, or perceive they are in 

 danger of being left upon the shore by the retreating tide, these 

 numerous spines perform the part of rakes, and scraping up the 

 sand, soon makes a kind of grave into which the creature sinks, 

 till it is covered over, securing for itself, by this proceeding, 

 safety from external violence and also water to respire until the 

 tide comes back. 



" Such power of walking in an animal that is enclosed on all 

 sides in a shelly box, seems in itself sufficiently surprising, but 

 when we learn that it can climb the cliff in search of food, and 

 even make its way, while pendant from the roof of rocky caverns, 

 we scarcely can conceive the possibility of its performing feats 

 so difficult, and eagerly inquire what means have been provided 

 for the purpose* 



" Whoever takes the trouble to observe the Echinus while alive, 

 confined in fresh sea water, or at large upon its native rock, will 

 not be long in doubt upon this point. Protruding from the shell, 

 and reaching past the points of even the longest spines, appear 

 innumerable suckers evidently similar in their construction, and 

 in function too, to those of the Asteridce. These are applied in 

 turn to the smooth inner surface of the glass, or to the stone on 

 which the creature climbs, and by the aid of this elaborate 



