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INTRODU CTI0N. 
PagO 
PALEOZOIC OR PRIMARY GROUP 1 
Laurentian System 1 
North America. Lower Laurentian 1 
Bohemia. Laurentian 1 
Silurian System. (Including “ Cambrian ” of some authors) 2 
British Isles. Lower Silurian : Wales and Scotland 2 
Upper Silurian : England 2 
Gothland. Upper Silurian 2 
Russia (Esthonia). Lower Silurian 2 
Bohemia. Silurian 3 
North America. Silurian 3 
Northern India. Lower Silurian 4 
Devonian System 4 
England 4 
Belgium 4 
Carboniferous System 4 
Britain : Scotland 4 
„ England 5 
Europe : Russia 5 
America, Arctic 6 
„ Indiana, U.S., N. America 6 
Australasia: Sumatra 6 
„ Tasmania 6 
Permian System 6 
England 6 
Germany 7 
MESOZOIC OR SECONDARY GROUP 7 
Triassic System 7 
Germany 7 
Jurassic System 7 
Lias Series. England 7 
Lower Lias. Gloucestershire 7 
Middle Lias. Banbury 8 
Upper Lias. Banbury 8 
Neocomian System. England 9 
Speeton Clay. Yorkshire 9 
Cretaceous System. British Isles 9 
England 9 
Gault. Folkestone, Kent 9 
Greensand (Upper Greensand) ; Cenomanian Series 9 
Chalk-marl (Turonian Series) and Lower Chalk 10 
Chalk (Senonian Series) 10 
„ ( „ „ ). Ireland 16 
Spain (Cenomanian ? Series) 17 
France (Albian P) 17 
