Cockle Shells

It is dictionary day again.  I did the shutting eyes and spinning it around thing, and my finger fell on “cockle”
There were three words cockle.  The one I plucked was in the middle.  Not the wrinkle in paper one or the purple flower often growing in the corn one.  It was the “edible bivalve” one “of the genus Cardium”  Maybe the genus did not need to be said.  It did for me though as I had no idea.  In fact I really still have no idea about what it is talking about.
It is a burrowing mollusc having 22 to 28 “ribs.”  Seeing a picture of them they are the predominant shells I see on the beach (the two halves make up the number of ribs).  I don’t think I see as many as I used to though.  I still find it fascinating to walk the beach looking at them.
In fact they are what I was photographing as I walked the beach.  To me they were just “shells” but my looking into these things shows me I was photographing them.  (I appreciate there are only some specific shells that are cockle shells, but all I was looking at had been said to be cockle shells.)
It is rare to find them in two parts which they have when alive and burrowing.  On the beach they have died and mostly the shells have been divided.
Cockle shells actually featured in stories my mum would tell.  When they holidayed at the beach, they would use these molluscs as bait.  They would lure the molluscs out into the open by waving a long something over their holes.  When they came out, mum would use her thumb and index finger to grab the molluscs before they could hide again.
I have never used them as bait, but have always found it fascinating to wander the beach seeing their shells.