— in New York, ix, 40, 41, 251, 402; xxi, 326.
— in Pennsylvania, x, 220; xiv, 7, 18.
— in Vermont, iv, 276.
Sphenophyllites, generic characters of, vii, 182.
Spherical trigonometry, elements of, xvii, 415.
Sphinges, North American, xxxvi, 282.
Spiders, mode of forming the web of, xviii, 165.
— and spider-webs, J. Edwards, xxi, 109.f
—, gossamer, xvi, 399.
—, snake suspended by, xxvii, 307.f