SYNOPSIS OP CONTENTS. iii 



PAGE 



B. — Summary of the characteristics of the Arctic Shell Beds : 



The Arctic Fossiliferous Clays do not necessarily belong to one Age . 11 



Fluctuations of Climate may have taken place . . .11 



Summary of Differences existing between Arctic Fossiliferous Clays : 



I.. They vary in position with respect to Boulder Clays . . 78 



11. Boulder Clays may be Arctic Shell-bearing Clays . • 78 



III. Distinctions exist between the Faunae of the separate Beds . 78 



IV. Several Littoral Shell Beds mark different Coast-lines . . 79 

 V. Shell Beds are found at varying heights . • .79 



VI. The Position of the Mytilus edulis Bed denotes differences in depths 



of water . . . . . .79 



C. — Series of Beds of later date, and not in any way Arctic, indicating the steps 

 through which the present physical geography of Scotland has been 

 reached since the retreat of the ice . . •. .80 



I. Deposits possibly belonging to a period of warmer-climate conditions 



than now exist . . . . .80 



1. Blair Drummond, Valley of the Forth . . 80 



2. Colintraive, Kyles of Bute . . .81 



3. Irvine Water, Ayrshire . . . .82 

 II. Series of Post-glacial deposits belonging to the most recent period 



of the depression of the land . , . .85 



Raised Beaches and Estuarine Beds . . .85 



Estuarine Muds of Firth of Tay and Firth of Forth . . 85 



Relation of the Estuarine Muds to old Sea Channel between the 



two Firths . . . . . .85 



Sections at Stirling and Bridge of Allan, with Ostracoda : 



1. Drip Bridge, Stirling . . . .86 



2. Brick-works south-west of Stirling . . 87 



3. Bridge of Allan . . . .88 

 Estuarine Muds at the Mouth of the South Esk . . 89 

 Varying heights above sea-level of Raised Beaches and Estuarine 



Muds, with Ostracoda . . . .89 



4. Paisley, Cardium edule Bed . . .89 



5. Isle of Cumbrae . . . .90 



6. West Tarbert Silt . . . .91 



7. Oban . . . . .92 



§ IV. General sequence of the Post-tertiary Beds or Scotland , . 93 



A, Pre-glacial Period . . . . , .94 



B. Glacial Period : 



I. Early Glacial . . . . . .94 



II. Middle Glacial . . , . . .94 



III. Final Glacial . . , , . .94 



