Fig. 11-7. (Upper picture) A rock-encrusting acorn barnacle (Ba/anus tinfinnabu/um). Its arthropod characteristic is 

 indicatecJ only by the jointed appendages which protrude between the valves of its shell. These are used to strain 

 the water for tiny sea animals that make up the diet of this strange arthropod. 



(Lower picture) The goose barnacle (Lepas anotifera) attached to a lobster pot buoy. The long stalks make it 

 possible for them to sample larger areas in search of food than is possible for the stationary acorn barnacle. 



