Might I not myself be mistaken?
Were we really crossing the layers of rock which overlie the granite foundation?
[1]The name given by Sir Roderick Murchison to a vast series of fossiliferous strata, which lies between the non-fossiliferous slaty schists below and the old red sandstone above.

The system is well developed in the region of Shropshire, etc., once inhabited by the Silures under Caractacus, or Caradoc.

(Tr.) If I am right, I thought, I must soon find some fossil remains of primitive life; and then we must yield to evidence.

I will look.
I had not gone a hundred paces before incontestable proofs presented themselves.

It could not be otherwise, for in the Silurian age the seas contained at least fifteen hundred vegetable and animal species.
My feet, which had become accustomed to the indurated lava floor, suddenly rested upon a dust composed of the _debris_ of plants and shells.