CHAPTER XIV.

The Cornstone Formation and its Organisms.--Dwarf Vegetation.--_Cephalaspides._--Huge Lobster.--Habitats of the existing Crustacea.--No unapt representation of the Deposit of Balruddery, furnished by a land-locked Bay in the neighborhood of Cromarty.--Vast Space occupied by the Geological Formations.--Contrasted with the half-formed Deposits which represent the existing Creation.--Inference.--The formation of the _Holoptychius_.--Probable origin of its Siliceous Limestone.--Marked increase in the Bulk of the Existences of the System.--Conjectural Cause.--The Coal Measures.--The Limestone of Burdie House Conclusion, 243-259

Ichthyolites of the Old Red Sandstone--from Agassiz's "Poissons Fossiles," 261-288

EXPLANATIONS OF THE SECTIONS AND PLATES.

SECTION I.

Represents the Old Red System of Scotland from its upper beds of Yellow Quartzose Sandstone to its Great Conglomerate base. _a._ Quartzose Yellow Sandstone, _b._ Impure concretionary limestone enclosing masses of chert, _c._ Red and variegated sandstones and conglomerate. These three deposits constitute an upper formation of the system, characterized by its peculiar group of fossils. (See