[116]. Dana, E. S., the Journal, 8, 390–392, 1874.
[117]. Zirkel, Geological Exploration of the 40th Parallel; vol. VI, Microscopical Petrography.
[118]. Caswell, Microscopical Petrography of the Black Hills. U. S. Geog. and Geol. Surv. Rocky Mts. Rep. on Black Hills of Dakota, 469–527. The separate copies issued bear the imprint 1876; the complete report 1880.
[119]. Dana, E. S., Igneous Rocks in the Judith Mts. Rep. of Reconnaissance Carroll, Mont., to Yellowstone Park in 1875. Col. Wm. Ludlow, War Dept., Washington, 105–106.
[120]. Hawes, G. W., Rocks of the Chlorite Formation, etc., the Journal, 11, 122–126, 1876. Greenstones of New Hampshire, etc, ibid., 12, 129–137, 1876.
[121]. Hawes, G. W., the Journal, 21, 21–32, 1881.
[122]. Brögger, Die silurischen Etagen 2 und 3, Kristiania, 1882.
[123]. The references for the papers alluded to, all of them in the Journal, are as follows:
Emerson, 24, 195–202, 270–278, 349–359, 1882;
——, 23, 302–308, 1882.