Holmes, Mr. W. H., on the Elk Mountains, 70 La Lata and Carriso Mountains, 69 Hopkins on the power of currents, 106 Howell laccolite, 34 , Mr. Edwin E., Fossils discovered by, 5; observation of the Henry Mountains, 66; observation of the Navajo Mountain, 69 Hydrostatic equilibrium, Law of, 72 Igneous mountains of the Plateau Province, 67 Igneous rocks, Contraction of, by cooling, 75, 80 Inconsequent drainage, 143 Instability of divides, 139 drainage lines, 125 Interdependence of drainage slopes, 123, 141 Internal structure of laccolites, 55 Intrusive rocks of the Henry Mountains, 59, 61 Isolation of the Henry Mountains, 2, 18 Jerry Butte, 34 Jukes Butte, 46 Jukes, Prof. J. Beete, on prismatic structure, 76 Jura-Trias rock series, 5 Kaibab structure, 11 Laccolite A, 32 B, 32 C, 32 D, 35 E, 41 F, 42 , Geikie, 41 H, 46 , Hillers, 30 , History of the, 95 , Howell, 34 , Jukes, 46 , Marvine, 42 , Newberry, 41 of Mount Ellsworth, 27 of Mount Pennell, 36 of the western base of Mount Ellen, 40 , Peale, 47 , Possible analogues of the, 98 , Scrope, 47 , Sentinel, 38 , Shoulder, 42 , Steward, 32 , The, defined, 19 Laccolites, Age of the, discussed, 84 , Composite, 55 , Denudation of, 21 , Depth of cover of, 86, 94 , Detailed description of, 22 , Diameters of, 92 , Form of, 55, 91 , Holmes, 27 , Horizontal, distribution of, 20 intruded in soft beds, 58 , Limital area of, 90, 97 thickness of, 91 , Material of, 59 not prismatic, 55 of the Elk Mountains, 70 of other regions, 97; size limited, 86 subsequent to the strata which inclose them, 51 , Vertical distribution of, 21, 56, 65 Laccolitic mountains of the Plateau Province, 67, 69 structure characteristic of the Henry Mountains, 19, 53 Sierra La Sal, etc., 69 conditioned by densities, 74 correlated with acidic lavas, 71 , Discussion of the origin of, 72 Lake Bonneville, Outlet of, 134 , Great Salt, Outlet of, 134 Winipeg, Origin of, 126 Land, Agricultural, 152 , Grazing, 152 sculpture, Principles of, 99, 115 , Timber, 152 La Lata Mountains, 68, 69, 152 La Sal Mountains, 68, 69, 152 Law of divides, 116 , Exception to the, 122 Lewis Creek plain, 128 Limital area of laccolites, 90, 97 thickness of laccolites, 91 Load, Relation of, to comminution, 107 Mallet, Robert, C. E., on contraction of igneous rocks in cooling, 76 Marvine laccolite, 42 Ma-suk’ Plateau, 13 Sandstone, 4 Shale, 4 Maze arch, 44 Metamorphism in the Henry Mountains, 65 on Mount Ellen, 38 Ellsworth, 24 Hillers, 31 Holmes, 28 Minerals of the Henry Mountains, 61, 64 Monoclinal shifting, 135, 140