CAMBRIAN GROUP.

Below the Silurian strata in North Wales, and in the region of the Cumberland lakes, there are some slaty rocks, devoid of organic remains, or in which a few obscure traces only of fossils have been detected (for which the names of Cambrian and Cumbrian have been proposed). Whether these will ever be entitled by the specific distinctness of their fossils to rank as independent groups, we have not yet sufficient data to determine.

TABULAR VIEW OF FOSSILIFEROUS STRATA,

Showing the Order of Superposition or Chronological Succession of the principal European Groups.

I. POST-TERTIARY.
A. POST-PLIOCENE.
Periods and Groups. Examples. Observations.
1. Recent.
  • Peat mosses and shell-marl, with bones of land animals, human remains, and works of art.
  • Newer parts of modern deltas and coral reefs.
 All the imbedded shells, freshwater and marine, of living species, with occasional human remains and works of art.
2. Post-Pliocene.
  • Clay, marl, and volcanic tuff of Ischia, [p. 113.]
  • Loess of the Rhine, [p. 117.]
  • Newer part of boulder formation, with erratics, [p. 124.]
 All the shells of living species. No human remains or works of art. Bones of quadrupeds, partly of extinct species.
II. TERTIARY.
B. PLIOCENE.
3. Newer Pliocene or Pleistocene.
  • Boulder formation or drift of northern Europe and North America, chaps. 11. & 12.
  • Cavern deposits and osseous breccias, [p. 153.]
  • Fluvio-marine crag of Norwich, [p. 148.]
  • Limestone of Girgenti, in Sicily, [p. 152.]
  • Three-fourths of the fossil shells of existing species.
  • A majority of the mammalia extinct; but the genera corresponding with those now surviving in the same great geographical and zoological province, [p. 157.]
  • During part of this period icebergs frequent in the seas of the northern hemisphere, and glaciers on hills of moderate height.
4. Older Pliocene.
  • A third or more of the species of mollusca extinct.
  • Nearly, if not all, the mammalia extinct.
C. MIOCENE.
5. Miocene.
  • About two-thirds of the species of shells extinct.
  • The recent species of shells often not found in the adjoining seas, but in warmer latitudes.
  • All the mammalia extinct.
D. EOCENE.
6. Upper Eocene.
  • Upper marine of Paris basin, Fontainebleau sandstone, [p. 175.]
  • Upper freshwater and millstone of same.
  • Kleyn Spauwen beds, [p. 176.]
  • Hermsdorf tile-clay, near Berlin.
  • Mayence tertiary strata, [p. 177.]
  • Freshwater beds of Limagne d'Auvergne, [p. 181.]
  • Fossil shells of the Eocene period, with very few exceptions, extinct. Those which are identified with living species rarely belong to neighbouring regions
  • All the mammalia of extinct species, and the greater part of them of extinct genera.
  • Plants of Upper Eocene, indicating a south European or Mediterranean climate; those of Lower Eocene, a tropical climate.
7. Middle Eocene.
  • Paris gypsum with Paleotherium, &c., [p. 191.]
  • Freshwater and fluvio-marine beds of Headon Hill, Isle of Wight, [p. 197.]
  • Barton beds, Hants, [p. 198.]
  • Calcaire Grossier, Paris, [p. 193.]
  • Bagshot and Bracklesham beds, Surrey and Sussex, [p. 198.]
8. Lower Eocene.
  • London clay proper of Highgate Hill and Sheppey,—Bognor beds, Sussex, [p. 200.]
  • Sables inférieurs, and lits coquilliers of Paris basin, [p. 196.]
  • Mottled and plastic clays and sands of the Hampshire and London basins, [p. 203.]
  • Sables inférieurs and argiles plastiques of Paris basin, [p. 196.]
  • Nummulitic formation of the Alps, [p. 205.]
III. SECONDARY.
E. CRETACEOUS.
§ UPPER CRETACEOUS.
9. Maestricht beds.
  • Yellowish white limestone of Maestricht, [p. 209.]
  • Coralline limestone of Faxoe, Denmark, [p. 210.]
 Ammonite, Baculite, and Belemnite, associated with Cypræa, Oliva, Mitra, Trochus, &c. Large marine saurians.
10. Upper White Chalk. White chalk with flints of North and South Downs,— Surrey and Sussex, [p. 211.] Marine limestone formed in part of decomposed corals.
11. Lower White Chalk. Chalk without flints, and chalk marl, ibid.
12. Upper Greensand.
  • Loose sand, with bright green particles, ibid.
  • Firestone of Merstham, Kent, [p. 218.]
  • Marly stone, with layers of chert, south of Isle of Wight.
13. Gault. Dark blue marl at base of chalk escarpment,—Kent and Sussex, [p. 218.] Numerous extinct genera of conchiferous cephalopoda, Hamite, Scaphite, Ammonite, &c.
§§ LOWER CRETACEOUS.
14. Lower Greensand.
  • Sand with green matter,—Weald of Kent and Sussex, [p. 219.]
  • White, yellowish, and ferruginous sand, with concretions of limestone and chert,—Atherfield, Isle of Wight.
  • Limestone called Kentish Rag
 Species of shells, &c., nearly all distinct from those of Upper Cretaceous; most of the genera the same.
F. WEALDEN.
15. Weald Clay. Clay with occasional bands of limestone,—Weald of Kent, Surrey, and Sussex, [p. 227.] Of freshwater origin. Shells of pulmoniferous mollusca, and of Cypris. Land reptiles.
16. Hastings Sand. Sand with calciferous grit and clay,—Hastings, Sussex, Cuckfield, Kent, [p. 229.] Freshwater with intercalated bed of brackish and salt water origin. Shells of fluviatile and lacustrine genera. Reptiles of the genera Pterodactyle, Iguanodon, Megalosaurus, Plesiosaurus, Trionyx, and Emys.
17. Purbeck Beds. Limestones, calcareous slates and marls, [p. 231.] Chiefly freshwater, and divisible into three groups, each containing distinct species of freshwater mollusca and of entomostraca. Alternations of deposits formed in fresh, brackish, and marine water, and of ancient soils formed on land and retaining roots of trees. Plants chiefly cycads and conifers, [p. 231.]
G. OOLITE.
18. Upper Oolite.
  • a. Portland building stone, [p. 259.]
  • b. Portland sand.
  • c. Kimmeridge clay, Dorsetshire, [p. 260.]
  • Ammonites and Belemnites numerous.
  • Large saurians, as Pterodactyles, Plesiosaurs, Ichthyosaurs.
  • No cetaceans yet known, but three species of terrestrial mammalia, [p. 267], [268.] Preponderance of ganoid fish. The plants chiefly cycads, conifers, and ferns, with a few palms.
19. Middle Oolite.
  • a. Coral Rag, [p. 260.] Calcareous freestones, oolitic, } often full of corals. Oxfordshire.
  • b. Oxford clay—Dark blue clay,—Oxfordshire and midland counties, [p. 262.]
20. Lower Oolite.
  • a. Cornbrash and forest marble, Wiltshire, [p. 263.]
  • b. Great oolite and Stonesfield slate,—Bath, Bradford, Stonesfield near Woodstock, Oxfordshire, [p. 266.]
  • c. Fuller's earth,—Clay containing fuller's earth near Bath, [p. 272.]
  • d. Inferior oolite, calcareous freestone, and yellow sands,—Cotteswold Hills, Dundry Hill, near Bristol, [p. 272.]
H. LIAS.
21. Lias. Argillaceous limestone, marl and clay,—Lyme Regis, Dorsetshire, [p. 273.] Mollusca, reptiles, and fish of genera analogous to the oolitic.
I. TRIAS.
22. Upper Trias. Keuper of Germany, or variegated marls—Red, grey, green, blue, and white marls and sandstones with gypsum—Würtemberg, bone-bed of Axmouth, Dorset, [p. 289.] Batrachian reptiles, e.g. Labyrinthodon, Rhyncosaurus, &c. Cephalopoda: Ceratites. No Belemnites. Plants: Ferns, Cycads, Conifers.
23. Middle Trias or Muschelkalk. Compact greyish limestone with beds of dolomite and gypsum,—North of Germany, [p. 287.] Wanting in England. With Equisetites and Calamite.
24. Lower Trias.
  • Variegated or Bunter sandstone of Germans—Red and white spotted sandstone with gypsum and rock-salt, [p. 288.]
  • Part of New Red sandstone of Cheshire with rock-salt, [p. 294.]
 Plants different for the most part from those of the Upper Trias.
IV. PRIMARY.
K. PERMIAN.
25. Upper Permian.
  • Yellow magnesian limestone, Yorkshire and Durham, [p. 301.]
  • Zechstein of Thuringia, Upper part of Permian beds, Russia.
 Organic remains, both animal and vegetable, more allied to primary than to secondary periods.
26. Lower Permian.
  • a. Marl slate of Durham and Thuringia.
  • b. Lower New Red sandstone of north of England and Rothliegendes of Germany.
  • a. and b. Lower part of Permian beds, Russia, [p. 301.]
 Thecodont saurians. Heterocercal fish of genus Palæoniscus, &c.
L. CARBONIFEROUS.
27. Coal measures.
  • a. Strata of sandstone and shale, with beds of coal,—S. Wales and Northumberland, [p. 309.]
  • b. Millstone grit,—S. Wales, Bristol coal-field, Yorkshire, [p. 308.]
  • Great thickness of strata of fluvio-marine origin, with beds of coal of vegetable origin, based on soils retaining the roots of trees.
  • Oldest of known reptiles or Archegosaurus. Sauroid fish.
28. Mountain limestone.
  • Carboniferous or mountain limestone, with marine shells and corals.
  • Mendip Hills, and many parts of Ireland, [p. 340.]
  • Brachiopoda of genus Productus.
  • Cephalopoda of genera Cyrtoceras, Goniatite, Orthoceras.
  • Crustaceans of the genus Phillipsia.
  • Crinoideans abundant.
M. DEVONIAN.
29. Upper Devonian.
  • a. Yellow sandstone of Dura Den, Fife.
  • b. Red sandstone and marl with cornstone of Herefordshire and Forfarshire.
  • Paving and roofing-stone, Forfarshire.
  • Upper part of Devonian beds of South Devon.
  • Tribe of fish with hard coverings like chelonians, Pterichthys, Pamphractus, &c.; also of genera Cephalaspis, Holoptichius, &c.
  • No reptiles yet known.
30. Lower Devonian. Grey sandstone with Ichthyolites,—Caithness, Cromarty, and Orkney, Lower part of Devonian beds of South Devon, and green chloritic slates of Cornwall, limestone of Gerolstein, Eifel. Fish, partly of same genera, but of distinct species from those in Upper Devonian; Glyptolepis, Dipterus, also Osteolepis, Coccosteus, &c.
N. SILURIAN.
31. Upper Silurian.
  • a. Tilestone of Brecon and Caermarthen.
  • b. Limestone and shale, Ludlow, Shropshire.
  • c. Wenlock or Dudley limestone.
  • Oldest of fossil fish yet discovered.
  • Trilobites and Graptolites abundant.
  • Brachiopoda very numerous.
  • Cephalopoda: Bellerophon, Orthoceras.
32. Lower Silurian.
  • a. Caradoc sandstone, Caer Caradoc, Shropshire.
  • b. Llandeilo flags, calcareous flags and schists,—Builth, Radnorshire, Llandeilo, Caermarthenshire.
  • Same genera of invertebrate animals as in Upper Silurian, but species chiefly distinct. Trinucleus caractaci, Cystideæ, [p. 358.]
  • No land plants yet known.
  • Footprints of tortoise, see note, [p. 360.]