Red Crag

In the Red Crag, for instance, we find the first known ancestors of our common edible periwinkle and common edible mussel; and in the Coraline Crag, the first known ancestors of the common horse-mussel, the common whelk, the common oyster, and the great pecten.

The Testimony of the Rocks or, Geology in Its Bearings on the Two Theologies, Natural and Revealed Hugh Miller 1829