5IO HISTORICAL PALEONTOLOGY. 



III. KAINOZOIC OR TERTIARY EPOCH. 

 (Terrains Tertiaires.} 



11. EOCENE SERIES. 



a. Lower Eocene. British Thanet Sands, Plastic and Mottled Clays of 



Woolwich, London Clay. Foreign Sables de Bracheux and Argile 

 plastique of France. Claiborne beds of Alabama, United States. 



b. Middle Eocene. British Bagshot, Bracklesham and Barton beds, 



Headon Series, St Helens or Osborne Series. Foreign Calcaire 

 Grossier of France ; Nummulitic Limestone of the Alps; Jackson 

 beds of the United States. 



c. Upper Eocene. British Bembridge beds, Hempstead beds (Lower 



Miocene?). Foreign Gypseous Series of Montmartre in France, 

 Vicksburg and White River beds in the United States. 



12. MIOCENE SERIES. 



a. Lower Miocene. British Bovey Tracy lignites and clays, Leaf-beds of 



Mull in the Hebrides. Foreign Brown Coals of Germany and 

 Croatia, Lower Molasse of Switzerland. 



b. Upper Miocene. British Ferruginous Sands of North Downs (?). 



Foreign Faluns of Touraine, Epplesheim Sands, Upper Molasse of 

 Switzerland, Oeningen beds of Switzerland, Siwalik beds of India. 



13. PLIOCENE SERIES. 



a. Older Pliocene. British White Crag and Red Crag of Suffolk. 



Foreign Upper and Middle Crags of Antwerp, Sub-Apennine beds. 



b. Neiver Pliocene. British Norwich Crag. Foreign Lacustrine Strata 



of the Val d' Arno, near Florence. 



14. POST-TERTIARY SERIES. 



a. Post- Pliocene. Cave-deposits, High-level and low-level gravels, Glacial 



deposits, Forest-bed of Cromer, &c. 



b. Recent. Peat-mosses, recent river-gravels, lacustrine mud,&c. 



LAURENTIAN PERIOD. 



ROCKS OF THE PERIOD. The Laurentian Rocks have their 

 typical development in North America, especially in Canada. 

 In northern New York strata of -this age rise into the lofty 

 and rugged elevations of the Adirondacks, and similar rocks 

 occur in another area to the south of Lake Superior. The 

 Laurentian series is of vast thickness, and is divided into 

 a lower and upper division. The Lower Laurentian group 

 attains the enormous thickness of about 20,000 feet, and is 

 composed entirely of metamorphic rocks, consisting mainly of 

 gneiss interstratified with mica-schist, with great beds of quartz, 

 and massive beds of crystalline limestone, of which one varies 

 from 700 to 1500 feet in thickness. Conglomerates also oc- 

 cur, and there are vast deposits of magnetic and specular iron- 

 ore. Graphite or black-lead occurs disseminated in strings, 

 veins, and beds, through hundreds of feet of Lower Laurentian 

 strata, and its amount is calculated by Dr Dawson to be equal 



