52 ECHINODERMS. 



These Snake-tails live almost exclusively on sandy shores, and hide them- 

 selves 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 Gorgonise, 

 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 there- 

 fore 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 neigh- 

 bouring 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 suc- 

 cession, and likewise are attached 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 inhabitants 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 would scarcely 

 be formidable to animals possessed of any strength ; armed, however, as the 

 rays have been seen to be with hundreds of tenacious suckers, escape from 

 such a grasp is hopeless, for prey once seized is secured by every part of its 

 surface, and, in spite of its utmost efforts, is speedily dragged towards the 

 mouth of the star-fish, and engulfed in its capacious maw. Small crabs and 

 small shell-fish are swallowed entire, for the stomach is amazingly dilatable ; 

 but shell-fish of large size are not the less the victims of the creature's voracity, 

 although it cannot swallow them whole. The destruction which it commits 

 among oysters was well known to the ancients, who believed that it obtained 

 its supper by inserting one of its rays, after the manner of an oyster-knife, 

 between the shells when the oyster happened to lie with them partially open, 

 and that it then gradually forced itself in till the prey came in contact with 

 its mouth. This procedure, although sufficiently ingenious, is not the mode 

 pursued, at least by our modern star-fish, which has the singular faculty of 

 turning its stomach inside out and pouring from it a poisonous secretion, which 

 behig introduced between the shells of the oyster, deprives it of all power of 

 closing its valves. The protruded stomach of the star-fish is then thrust in, 

 and enveloping the poor oyster in its folds, literally eats it out of house and 

 home. These animals abound on every coast, frequenting quiet bays, where 



* dorr/p, aster, a star. 



