. STARFISH 



empty and limp. A wonderful system of pipes conveys the water through each 



ray to the sucker feet. 



Amongst these sucker feet may be found many tiny stalks, ending, not in 



suckers, but in three claws, continually 

 opening and shutting. These are " pedi- 

 cels," and their business is to take hold 

 of objects in lieu of the sucker feet, as 

 also to keep the latter free from dirt and 

 other clogging matter. 



The upper side is always rough to 

 the touch, being covered with limy plates 

 and bosses, in patterns which help to 

 distinguish the different species. 



Starfishes feed on molluscs, often 

 wreaking considerable havoc in oyster 

 and mussel beds, and an extraordinary 

 characteristic is seen in their manner of 

 feeding. The mouth being small, few, if 

 any, shellfish could be swallowed ; but 

 Under view of common Starfish, as an the starfish protrudes its stomach through 



example of Echinodermata: o, mouth; sp, fe mouth, SUITOUnds the shellfish, re- 



spines ; *' tu duces it to a fluid condition by its gastric 



juice, and thus takes it back through the mouth to its " inside." 



Another strange fact is that if a starfish loses a ray it can soon grow a new 

 one ; and if the creature is cut in two, each half begins to throw out new rays, 

 and thus it can " multiply by division," if 

 occasion arises. 



The female lays her eggs in a little 

 heap, and, bending her rays over them, 

 stands as it were on tiptoe guarding them. 

 The larva is a peculiar free-swimming 

 creature with two ciliated bands about an 

 inch long, long known as Bipinnaria aster- 

 igera, and classed among jelly-fish until its 

 true relationship was established, about 

 seventy years ago. Inside it the adult form 

 of the starfish is developed. 



The Spiny Star (Uraster glacialis) is not 

 so common as the preceding, but is much 

 larger. The bosses on the upper side are 

 much more spiny, and the colour, instead 

 of being red, is greenish. 



The Eyed Cribella (Cribella oculata) is purple, and quite smooth to the 

 touch. 



Upper view of common Starfish, as an 

 example of Echinodermata : a, anus ; 

 m, madreporite ; sp, spines. 



