— of New England and New Jersey, volcanic origin of, T. Cooper, iv, 239.
— —, igneous origin of, B. Silliman, xvii, 119.
— of New Jersey, connection with the sandstone, v, 240.
—, peculiar porous character of, v, 240.
—, and minerals of, in Nova Scotia, by Jackson and Alger, xiv, 305; xv, 132f, 204.
— of the Copper Mountains, northern America, xvii, 8.
— dikes, crescent form of, first observed by J. G. Percival, xlvi, 205.
— —, — —, remarks on, xlv, 334.
— — of Maine, of four different ages, C. T. Jackson, xxxvi, 145.
— — in Vermont, at Montgomery, xxii, 189.