CONTENTS vu 
CHAPTER XXXIX 
PAGE 
The Basalt-Plateaux of Skye and of the Faroe Isles .... 249 
CHAPTER XL 
The Modern Volcanoes of Iceland as illustrative of the Tertiary Vol- 
canic History of North-Western Europe ..... 260 
CHAPTER XLI 
The Eruptive Vents of the Basalt-Plateaux 
Vents filled with Basalt or other Lava-form Rock — Vents filled with Agglomerate . .270 
CHAPTER XLII 
The Basic Sills of the Basalt-Plateaux . . . . . .298 
CHAPTER XLIII 
The Bosses and Sheets of Gabbro 
Petrography of the Rocks — Relations of the Gabhros to the other members of the Volcanic 
series— Description of the Gabbro districts— Skye ..... 327 
CHAPTER XLIV 
The Bosses and Sheets of Gabbro in the Districts of Rum, Ardnamurchan, 
Mull, St. Kilda and North-East Ireland. History of the Gabbro 
Intrusions .......... 349 
CHAPTER XLV 
The Acid Rocks 
Their Petrography — Their Stratigraphical Position and its Analogies in Central France . 364 
CHAPTER XLVI 
Types of Structure in the Acid Rocks — Bosses 
. 378 
