CHAPTER XXVI.

OLD RED SANDSTONE, OR DEVONIAN GROUP.

Old Red Sandstone of Scotland, and borders of Wales--Fossils usually rare--"Old Red" in Forfarshire--Ichthyolites of Caithness--Distinct lithological type of Old Red in Devon and Cornwall--Term "Devonian"--Organic remains of intermediate character between those of the Carboniferous and Silurian systems--Corals and shells--Devonian strata of Westphalia, the Eifel, Russia, and the United States--Coral reef at Falls of the Ohio--Devonian Flora 342