These pale gray acorn barnacles live all over the rocks along the shore at Casperson Beach.
They attach themselves permanently to a hard surface growing their shells directly onto the rocks here.
The shells are usually constructed of six plates — and reach into the water column with modified legs. These feathery appendages beat rhythmically to draw plankton and detritus into the shell for food.
This Wikepedia video of barnacles feeding is too good to miss:
http://en.wikipedia.org/wiki/File:Semibalanus_balanoides_upernavik_2007-07-05.oggWould the snails here eat the barnacles if they could? You bet!