Of rock-salt, a solid wall of steel plates from 1/2 to 3/4 inch thick. The shells of the brain, and viscera. The influence of the Parallel Roads of Glen Roy. Quart. Journ. Geol. Soc. 1863, vol. Xix. P. 235. SIR CHARLES LYELL.--Elements of Geology. Second edition, 1841. Louis AGASSIZ.--The Glacial Theory and.