SYNOPSIS or CONTENTS. 



iii 



PAGE 



B. — Summary of tlie cbaracteristics of the Arctic Shell Beds : 



The Arctic Fossiliferous Clays do not necessarily belong to one Age . 77 

 Fluctuations of Climate may have taken place . . .77 



Summary of Differences existing between Arctic Fossiliferous Clays : 



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

 II. 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 



1. 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 AUan, 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 . . . . .93 



§ IV. General sequence of the Post-tertiary Beds of Scotland . , 9'^ 



A, Pre-glacial Period . . . . . , 9 i 



B. Glacial Period : 



I. Early Glacial ...... 9 



II. Middle Glacial . . . . . . 9i 



III. Final Glacial ...... Si, 



