SEA-SIDE STUDIES. 



321 



sometimes so abundant that it gives a rosy hue to considerable areas 

 of the sea. It attains a length of three or four inches, and in form is 

 not very unlike an elongated melon with one end cut square off. 



Closely related to idyia is pleurohrachia, one of the commonest of 

 the " comb-bearers," or Ctenophonx^ on the northern coast of the United 

 States. This jelly-fish, less than an inch in length, like all other Cte- 

 nophorm^ has eight rows of locomotive fringes dividing the surface of 

 the body into regions as the ribs divide the surface of a musk-melon. 

 Besides these eight rows of fringes, or locomotive organs, it has two 

 most extraordinary tentacles ; and no form of expansion, or contrac- 

 tion, or curve, or spiral, can be conceived of, which these wonderfully 

 constructed tentacles do not assume as this transparent jelly-fish moves 

 freely through the water. 



If the visitor to the sea-shore will ^o down among the big rocks 

 left bare by the retiring tide, and will lift up the long sea-weeds which 

 hang from their sides, he will find the curious "starfishes," or "sea- 

 stars," in some cases in great profusion, and clinging to the. surface of 

 the rock so firmly that they often leave some of their locomotive suck- 

 ers attached when too quickly lifted from their places. 



The starfishes have the body so gradually merging into the arms 



r f^fYr—i\*\rr''\^~^ 



.^ 





}^^^ 



Fig. 22.— Starfish {Asteracanthlori). 



or rays that one can hardly tell where the body ends and the arms 

 begin ; and this enables one to readily distinguish them at sight from 

 the "serpent-stars," which are sometimes called star-fishes, and of 



VOL. XIII. — 21 



