Fig. 1. Section of augite crystal from the lava of 1794, with numerous gas cells and delicately banded walls. The interior contains two long prisms, probably of apatite.
" 2. Crystal of augite with banded walls, and indented by leucite crystals, from the lava of 1794. Mag., 40 diams.
" 3, 4, 5. Sections of augite crystals from the lavas of 1794 and 1820.
" 6. Group of augite crystals from the lava of 1835.
" 7. Ditto from the lava of 1822, with encluded mica-flake (a) and portion of the glass paste, or ground-mass, of the rock (b), containing microliths and grains of magnetite.
Fig. 8. Two crystals of olivine from the lava of 1855; they are intersected on one side by the plane of the thin section, and are remarkable for showing lines of gas cells, and bands of growth sometimes cellular. Mag., 40 diams.
" 9. Section of rock-crystal (quartz), with double terminal pyramids, from the lava of 1850.
" 10. Twin crystal of sanidine from the lava of 1858. Mag., 40 diams.
" 11, 12, 13. Sections of plagioclase crystals (probably labradorite) from the lava of 1855. Mag., 100 diams.
" 14. Section of olivine crystal from the lava of 1631—imperfectly formed. Mag., 30 diams.
" 15. Section of mica-flake from the lava of 1822. Mag., 30 diams.
