Shells In Rock

I've been along the quarry road,
And I have watched men digging wells,
And everywhere it was the same--
The stones were full of little shells.
And they are packed away in rock;
They're under sand and under clay;
And some one said that they were left
When the ocean went away.
I saw them in the stones that make
A church, and in a bridge.
They're hidden in the solid rock
But they show along the edge.
You see them in foundation stones;
They show in creeks and waterfalls;
And once I saw them on the jail--
More little shells in walls.
We walk on them when we walk on roads;
And they're packed under all the hills.
Suppose the sea should come back here
And gather up its shells.