CHAPTER VIII.

Upper Formations of the Old Red Sandstone.--Room enough, for each and to spare.--Middle, or Cornstone Formation.--The Cephalaspis its most characteristic Organism.--Description.--The Den of Balruddery richer in the Fossils of this middle Formation than any other Locality yet discovered.--Various Contemporaries of the _Cephalaspis._--Vegetable Impressions.--Gigantic Crustacean.--_Seraphim._--Ichthyodorulites.--Sketch of the Geology of Forfarshire.--Its older Deposits of the Cornstone Formation.--The Quarries of Carmylie.--Their Vegetable and Animal Remains.--The Upper Formation.--Wide Extent of the Fauna and Flora of the earlier Formations.--Probable Cause, 125-150