110 



MARINE ANIMALS OF MASSACHUSETTS BAY. 



(Fig. 143), around which the pedicellariae are arranged in a close 

 wreath, in the centre of which the summit of the spine projects ; 

 they differ also from tliose of the Sea-urchin in having two 

 prongs instead of three. Other pedicellariae are scattered inde- 

 pendently over the surface of the animal, but they are smaller 



than those forming the clusters and connected with the spines. 

 The fvmction of these organs in the Star-fish remains unexplained ; 

 the opening on the upper surface, through which the refuse food 

 is thrown out, is in such a position that they evidently do not 

 serve here the same purpose which renders them so useful to the 

 Sea-urchin. Occasionally they may be seen to catch small prey 



Kig M2 Slai-lisli ; iiiituiiiJ size, seen from above. 



