. 948 
613; proximity of land, 618; former 
climates, 613; upheaval, 276; as guides 
to geological chronology, 614, 631; may 
prove inversion of strata, 616; prove 
Japse of interval between strata, 620, 
632; succession of as a measure of geo- 
logical time, 55; as guides to strati- 
graphical classification, 500, 622, 632; 
succession of influenced by physical 
conditions, 623; subsequent alterations 
of into casts, 610; deformation of, 301, 
812; occurrence of in altered rocks, 
304 
Fox, fossil, 875, 898, 906 
Fox Hills Group, 832 
Foyaite, 138 
Fracture of rocks, 91 
~Fragmental rocks, 102, 153 
France, sand dunes of, 323; river floods 
of, 359; river terraces of, 383; river- 
mouths of, 389; local metamorphism in, 
581; Cambrian rocks in, 658; Silurian, 
690 ; Devonian, 701, 703 ; Carboniferous, 
745: Permian," 758);.- ‘Dnas, 9 767; 
Jurassic, 796; Cretaceous, 824; Hocene, 
847; Oligocene, 858, 861; Miocene, 
865; Pliocene, 876; Pleistocene, 898 ; 
paleeolithic gravels and caverns, 908 
Frasnien, 701 
Fresh water, destructive effects of on 
marine fauna, 607 
Fresh-water limestone, 167 
Freestone, 158 
Friable condition of rocks, 91 
Frog, early species of, 868 
Frost, influence of on river transport, 
368 ; effects of on soils, rocks, &c., 401 
Frozen rivers and lakes, geological action 
of, 401 
Fruchtschiefer, 123, 580 
Fucoids, fossil, 649, 658, 662 
Fulgurites or lightning tubes, 319 
Fuller’s earth, 161 
Fuller’s-earth Group, 792 
Fumaroles, 229 
Fundy, bore in Bay of, 420; destruction of 
fish in Bay of, 607 
Fusibility of minerals, relative order of 
not always followed in nature, 99, 295 
Fusion, effect of in expanding rocks, 284 ; 
a 1esult of rock-crushing, 291; experi- 
ments in, 292, 294, 295; artificial and 
natural compared, 295; rarely anhby- 
drous, 297 ; observed in blocks in tufts, 
574 
Fusulina, 722 
usus, 793, 806, 840, 841*, 855, 873, 881 
Gabbro, 64, 149 
Gaj Group (Tertiary), 869 
Galeocerdo, 850 
Galerites, 804, 805* 
Galestes, 783 
Galethylax, 856 
INDEX. 
Gallicia, naphtha springs of, 236 
Gangamopteris, 771 
Ganges, periodical floods of the, 359; 
mineral matter in water cf, 370; delta 
of, 390; area of basin, 444; annual dis- 
charge of sediment, 444; rate of erosion, 
444 
Gannister, 160, 737, 741 
Garbenschiefer, 123 
Garnet, 79; produced by metamorphism in 
limestone shale, 578 
Garnet-olivine-rock, 151 
Garnet-rock, 125 
Garonne, mineral matter in water of, 370 
Gas inclusions in rocks, 96, 98 
Gas-springs, 235 
Gas-spurts, traces of among strata, 486 
Gascony, sand-dunes of, 323 
Gases from volcanoes, 198, 201, 235 
Gaudryina, 803* 
Gault, 814, 818, 825, 828, 829 
Gavialis, 850 
Gaylussite, formation of in bitter lakes, 400 
Gazella, 879; fossil forms of, 872 
Gedinnien, 702 
Gelocus, 856 
Genessee Group, 705 
Geneva, Lake of (see Lake Geneva) 
Geognosy, 4, 30 
Geographical distribution of plants and 
animals, 618 ye 
Geological action may have been formerly 
more vigorous, 19, 21, 195 
Geological Congress, International, 635 
Geological nomenclature, 635, 784 
Geological record, subdivision of by fossils, 
616, 622, 631; imperfection of, 3, 619, 
634, 648; causes of gaps in, 621 
Geological Society of London, founded, 6 
Geological structure, influence of in land- 
sculpture, 922 
Geology, aim of, 1,6; reveals no trace of 
the beginning of things, 6; Cosmical 
aspects of, 6; Dynamical, 195; Experi- 
menta], 289; Geotectonic or Structural, 
474; Paleontological, 603; Physiogra- 
phical, 910; Stratigraphical, 631 
Georgian rocks, 660 
Germany, Archean rocks, 644; Cambrian, 
658, 691; Silurian, 691; Devonian, 701 ; 
Carboniferous, 747; Permian or Dyas, 
756; Trias, 767; Jurassic, 798; Cres 
taceous, 828; Oligocene, 859; Miocene, 
866; Pliocene, 876; Glaciation of, 886, 
897 i 
Gervillia, 762, 774 
Geyserite, 117 
Geysirs, 236 : 
Giants’ Kettles,’ 415, 888 
Gilbertsocrinus, 722 
Giraffe, fossil forms of, 872, 878 
Givetien, 702 
Glacial action, Pre-Cambrian (?), 656; 
Old Red Sandstone (?), 707, 716; Per- 
