Keuper beds of Germany (p. 375). St. Cassian or Hallstadt beds, with rich marine fauna (p. 376). Coal-field of Richmond, Virginia (p. 382). Chatham coal-field, North Carolina (p. 383). 17. MIDDLE TRIAS. British Wanting. Foreign Muschelkalk of Germany (p. 378). 18. LOWER TRIAS. British Bunter or Lower New Red sandstone of Lancashire and Cheshire (p. 372). Foreign Bunter-sandstein of Germany (p. 380). Red sandstone of Connecticut Valley, with footprints of birds and reptiles (p. 381). PRIMARY OR PALÆOZOIC EXAMPLES PERMIAN 19. PERMIAN. British Upper Permian of St. Bees’ Head, Cumberland (p. 386). Middle Permian, magnesian limestone, and marl-slate of Durham and Yorkshire, with _Protosaurus_ (p. 387). Lower Permian sandstones and breccias of Penrith and Dumfriesshire, intercalated (p. 390). Foreign Dark-coloured shales of Thuringia (p. 392). Zechstein or Dolomitic limestone (p. 392). Mergel-schiefer or Kupfer-schiefer (p. 392). Rothliegendes of Thuringia, with _Psaronius_ (p. 392). Magnesian limestones, etc., of Russia (p. 393). CARBONIFEROUS 20. UPPER CARBONIFEROUS. British Coal-measures of South Wales, with underclays inclosing _Stigmaria_ (p. 397). Coal-measures of north and central England (p. 395). Millstone grit (p. 395). Yoredale series of Yorkshire (p. 395). Coal-field of Kilkenny with _Labyrinthodont_ (p. 407). Foreign Coal-field of Saarbruck, with _Archegosaurus_ (p. 406). Carboniferous strata of South Joggins, Nova Scotia (p. 409). Pennsylvania coal-field (p. 403). 21. LOWER CARBONIFEROUS. British Mountain limestone of Wales and South of England (p. 430). Same in Ireland (p. 437437). Carboniferous limestone of Scotland alternating with coal-bearing sandstones (p. 396). Erect trees in volcanic ash in the Island of Arran (p. 546). Foreign Mountain limestone of Belgium (p. 436). DEVONIAN or OLD RED SANDSTONE 22. UPPER DEVONIAN. British Yellow sandstone of Dura Den, with _Holoptychius_, etc. (p. 440); and of Ireland with _Anodon Jukesii_ (p. 441). Sandstones of Forfarshire and Perthshire, with _Holoptychius_, etc. (p. 442). Pilton group of North Devon (p. 449). Petherwyn group of Cornwall, with _Clymenia_ and _Cypridina_ (p. 451). Foreign Clymenien-kalk and Cypridinen-schiefer of Germany (p. 450) 23. MIDDLE DEVONIAN. British Bituminous schists of Gamrie, Caithness, etc., with numerous fish (p. 443). Ilfracombe beds with peculiar trilobites and corals (p. 450). Limestones of Torquay, with broad-winged Spirifers (p. 451). Foreign Eifel limestone, with underlying schists containing _Calceola_ (p. 453). Devonian strata of Russia (p. 454). 24. LOWER DEVONIAN. British Arbroath paving-stones, with _Cephalaspis_ and _Pterygotus_ (p. 446). Lower sandstones of Forfarshire, with _Pterygotus_ (p. 446). Sandstones and slates of the Foreland and Linton (p. 454). Foreign Oriskany sandstone of Western Canada and New York (p. 456). Sandstones of Gaspe, with _Cephalaspis_ (p. 455 ). EXAMPLES