EXPLANATION OF PLATE III.
MAGNIFIED SECTIONS OF VOLCANIC ROCKS.
1. Diorite dyke, traversing Assynt limestone, North Highlands.
2. Basalt from upper beds, near Giant's Causeway, County Antrim.
3. Hornblende-hypersthene-augite Andesite, from Pichupichu, Andes.
4. Augite-Andesite from Pichupichu, Andes.
5. Olivine dolerite, with hornblende and biotite, Madagascar.
6. Leucite basalt, with mellilite, Capo di Bove, Italy.
Plate IV.
