68 ECHINODEKMATA. 



faculty renders the preservation of a perfect specimen 

 very difficult. 



These Snake-tails live almost exclusively on sandy 

 shores, and hide themselves in the sand or mud at the 

 slightest appearance of danger. In our own seas they are 

 very abundant, and are amongst the most curious and 

 beautiful game sought after by the dredger. 



Some species are always found firmly grasping the 

 stems of Gorgonias, amongst which they seem to live like 

 spiders, catching any passing animals by means of their 

 long flexible arms. 



The Star-fishes (Asterias)* (Fig. 44, 3). 



In these well-known animals it is evident that the power 

 of locomotion, so far as depends upon the flexibility of 

 the rays, must be entirely lost ; it, therefore, becomes an 

 interesting question how progression is now to be effected 

 under such altered circumstances. On placing a living 

 star-fish in some transparent pool left by the tide, and 

 watching it there, the most incurious observer will find 

 himself compelled to gaze in mute astonishment at what 

 he sees. From the inferior surface of each ray, the 

 creature, which before appeared so helpless and inanimate, 

 slowly protrudes numbers of fleshy tubes, which move 

 about in search of a firm holding-place, and soon are fixed, 

 by means of little suckers at the end of each, to the 

 smooth surface of a neighbouring stone ; or, if the star- 

 fish has been placed in a glass vessel filled with sea-water, 

 to the inner surface of the glass, where every movement 

 may be plainly seen. When these have laid fast hold, 

 others appear in quick succession, and likewise are at- 

 tached to the smooth surface, till at last hundreds of 

 little legs, for such these suckers seem, are actively 

 employed, and by their aid the creature glides along with 

 such a gentle motion that it seems to swim rather than 

 crawl. 



But it is not merely as agents of locomotion that the 

 suckers are used, for helpless as these creatures seem to 

 be, they are in reality among the most voracious inha- 

 bitants of the deep. When seizing its food, the rays of 

 the star-fish are bent so as to form a kind of cup, in the 

 centre of which is the opening of the mouth. The cup 

 thus formed will, to a certain extent, lay hold of a passing 

 victim, but without other means of securing it, the grasp 

 , aster, a star. 



