CHAPTER XXXII.

ON THE DIFFERENT AGES OF THE VOLCANIC ROCKS--_continued_.

Volcanic rocks of the Pliocene and Miocene periods continued--Auvergne--Mont Dor--Breccias and alluviums of Mont Perrier, with bones of quadrupeds--River dammed up by lava-current--Range of minor cones from Auvergne to the Vivarais--Monts Dome--Puy de Come--Puy de Pariou--Cones not denuded by general flood--Velay--Bones of quadrupeds buried in scoriae--Cantal--Eocene volcanic rocks--Tuffs near Clermont--Hill of Gergovia--Trap of Cretaceous period--Oolitic period--New Red Sandstone period--Carboniferous period--Old Red Sandstone period--"Rock and Spindle" near St. Andrews--Silurian period--Cambrian volcanic rocks 422