
INDEX. 
s 
Diospyros, 846 
Dip of strata, 509; observation of, 510; 
deceptive appearances of, 510; quaqua- 
versal, 511 
Diphya Limestone, 800 
_ Diplacanthus, 710 
Diplacodon Beds, 853 
Diplograptus, 663* 
Diplopterus, 710 
Diplopus, 841 
Diplosaurus, 808 
Dipteronotus, 765 
Dipterus, 709* 
Dipyre Slate, 122 
Dirt beds, 796 
Discina, 650*, 651, 665, 669*, 723, 795 
Discinocaris, 664, 670 
Discites, 724 
Discoidea, 804 
Discosaurus, 810 
Disintegration from rapid daily changes of 
temperature, 319, 325; from solvent 
action of rain, 332, 334; produces deep 
_ accumulations of rotted rock, 338, 453 
Dislocations of the earth’s crust, or Faults 
(which see), 315, 522 
Distribution of plants and animals, 283 
Dithyrocaris, 724 
Ditroite, 138 
Ditrupa, 849 
Dog, early forms of, 856 
- Dogger, 793, 799 
Dogwood, early forms of, 832 
Dolerite, 148 ; weathering of, 76 
Dolichosaurus, 808 
Dolichosoma, 754 
Dolinas in limestone districts, 855, 830 
Dolomite, 83, 114, 755; origin of, 304, 
399 ; Devonian, 704 ; Carboniferous, 719; 
Permian, 751; Triassic, 769 
Dolomitic conglomerate of English Trias, 
. 486, 493, 759, 765 
Dolomitization, 115, 304, 720, 738 
Dolphin, early forms of, 865, 875 
Dorcatherium, 869, 880 
Dormouse, early forms of, 856 
Dorsetshire, landslips of, 357 
Dorycordaites, 745 
_ Dover, Strait of, 488 
Downton Sandstone, 682 
Drainage-basins, influence of permeability 
of rocks in, upon discharge of rivers, 
359, 361; character of river water in, 
dependent upon chemical composition of 
rocks, 364 
Drainage lines, permanence of, 922 
Dranse, glacier-dammed river of, 369 
Dreissena, 866 
Dremotherium, 856, 878 
Drepanodon, 880 
Dricroceras, 863 
Drift, glacial, 888; contorted beds of, 
891 
Dromatherium, 763 
945 
Droughts in relation to springs and rivers, 
359 
Druid stones, 342 
Drums of boulder clay, 889 
Drusy cavities, 62, 95, 131, 593 
Dryandra, 855, 862 
Dryandroides, 855 
Dryolestes, 801 
Dryopithecus, 864* 
Dunes, 155; formation of, 322; progress 
of, 324; arrest of by planting pines, 3?4, 
456; and by sand-carex, 456 
Dunite, 151 
Dura Den beds, 711, 716 
Durance, slope of the, 363 ; mineral matter 
in water of, 370 
Dust, in the air, 31; erosion by wind- 
driven, 320; growth of, 321; showers, 
325 
Dyas system, 750 
Dykes, volcanic, 105, 213, 223, 247, 553, 
858 
Eagle, fossil, 881 
Eagle-stones, 175 
Earth, density of, 8, 42,43; form and size 
of, 11; movements of, 13; crust of (see 
Crust); stability of axis of, 15; eccen- 
tricity of orbit of, 23; composition and 
pressure of interior of, 44; internal heat 
of, 45, 55; condition of interior of, 49; 
age of, 54 
Earth pillars eroded by rain, 341 
Earthquakes defined, 266; waves, 267; 
velocity of, 267; duration of, 268; in- 
fluenced by structure of terrestrial crust, 
268; areas affected by, 269; depth of 
source, 269; geological effects of, 271; 
distribution of, 273; destroy marine 
organisms, 607; considered as evidence 
of liquidity of earth’s interior, 50; origin 
of, 273; most frequent in winter, 274 
Earthworm assists in the formation of 
vegetable soil, 339, 341, 454 
Earthy condition of rocks, 91 
Echinobrissus, 773, 804 
Echinoconus, 804, 805* 
Echinocorys, 823 
Echinoderms as fossils, 611 
Echinoids, fossil, in relation to the theory 
of development, 625; survival of from 
Cretaceous time, 804 
Echinospherites, 664 
Ecliptic, obliquity of, as a geological 
factor, 15 
4 Eclogite, 125 
Ecuador, voleanic action in, 218 
Edmondia, 725, 753 
Efflorescences of arid soils, 527 
Egeln Beds (Oligocene), 860 
Egypt, periodical floods of, 359 
Kifel, volcanic phenomena of, 202, 207, 
209, 216, 235, 244, 245, 560; gas springs 
of, 202, 235; crater lakes of, 240, 248 
Gee 
