204 



THE SEAS 



tentacles and playing them like an angler. Starfish and 

 brittlestars crawl about on rocks or in the sand and devour 

 any suitable animal which they can find, the former seizing 

 them with their tube-feet, and the latter wrapping them 

 round with their very active arms. In both cases the prey 

 is carried to the mouth and swallowed, but the common 



Fig. 43. — A medusa, Leuckartiara ociona, catching and feeding on young fish (x 2) 



starfish is also able to feed on animals much larger than 

 itself by the simple and convenient process of protruding its 

 stomach over any animal which it cannot swallow. They 

 consume great numbers of bivalve shellfish over which they 

 hunch their bodies, gradually forcing the shell valves 

 open by the continuous pulling action of their tube-feet 

 for, though the closing muscles of the bivalve shell are 



