—, compared crystallographically with Kyanite, C. U. Shepard, xii, 59.f
—, crystal of, with analyses, xlvi, 381.f
—, analysis of, xlviii, 219.
—, analysis by T. Thomson, xlix, 396.
—, locality of, and of monazite, in Westchester Co., N. Y., xlvi, 207.
Silphium, v, 301.
Silurian or transition system, xxxv, 243.
— — —, R. I. Murchison on, noticed, xxxvi, 399; xxxvii, 219; xliv, 193.
— system of England and Europe, xxxvii, 219.
— rocks of Denbigshire, J. E. Bowman, xlii, 325.