That swarmed above in the more lucid green
Ten thousand fathoms nearer to the sun.
There they lived out their gleam of life and died,
Then slowly drifted down into the dark,
And spread in layers upon the cold sea-bed
The invisible grains and flakes that were their bones.
Layer on layer of flakes and grains of lime,
Where life could never build, they built it up
By their incessant death. Though but an inch
In every thousand years, they built it up,