966 
Soil-cap, its influence on dip of rocks, 
511 
Soissonais, lignites of the, 848 
Solarium, 806 
Solemya, 753 
Solenhofen Limestone, 799 
Solenopleura, 658 . 
Solfataras, 201, 209 
Solution by rain-water, 332 
Somma, Monte, 206, 208, 209 
Soolquellen, 350 
Sorex (shrew), 875 
Sowerbya, 795 : 
Spain, Archean rocks of, 645; Cambrian, 
657, 660; Silurian, 691; Devonian, 703; 
Carboniferous, 745, 747; Trias, 767 
Spalacotherium, 783 
Sparagmite of Norway, 657 
Sparodus, 754 
Spars, 592 
Spatangenkalk, 829 
“Spates” or floods, 359 
Species, Darwin on origin of, 624 
Specific gravity of rocks, 93; reduction of 
in fresh water, 368: and, in sea-water, 
428 
Spectrum-analysis, 9 
Speeton Clay, 816 
Spherodus, 807 
Sphxronites, 664 
Spheerosiderite, 83, 116, 720 
Sphzxrospongia, 668 
Sphzrulites, 806 
Sphagodus, 666 
Sphene, 80 
Sphenonchus, 765 
Sphenophyllum, 662, 726 
Sphenopteris, 708, 726, 727*, 756, 771*, 
817 
Sphenozamites, 772 
Spheroids of weathering, 335, 488, 507 
Spherulite-rock, 141 
Spherulites, artificially formed in glass, 
301 
Spherulitic structure, 89, 135, 141 
Spider, earliest forms of, 732 
Spilosite, 578 
Spindle-trees, fossil, 855 
Spiriferina, 775*, 789 
Spirifera, 665, 696, 698*, 718, 723%, '753, 
761, 773 
Spirigera, 696 
Spirorbis, 664, 718, 723 
Spitzbergen, elevation of, 276, 280; effects 
of frost at, 401; Tertiary flora of, 
868 
Splintery fracture, 91 
Spondylus, 805, 806*, 847, 862 
Sponges, spicules of in siliceous deposits, 
469; fossil, 650, 663, 797, 804* 
Springs, origin of, 344; indicate position 
of faults, 534; kinds of, 344; surface or 
simple, 344; deep-seated, 345; tempe- 
rature of, 346 : thermal, 45, 347, 348, 599; 
INDEX. 

thermal connected with mountain-crump- 
ling, 917; chemical action of, 347, 351, 
355; chemical constituents of, 347, 348; 
common or! potable, 348; mineral, 349 ; 
relation of their composition to nature of 
surrounding rocks, 349; saline from old 
voleanic rocks, 202; calcareous, 349, 
354, 609; ferruginous or chalybeate, 350, ~ 
354; brine, 350; medicinal, 351; sulphur, 
351; oil, 351; deposits from, 353; si- 
liceous, 236, 354; yearly amount of mine- 
ral matter removed by, 355; drying up 
of, 359; relation of to river-supply, 359 ; 
preservation of organic remains in de- 
posits of, 606 
Spruce, fossil, 868, 875 
Sprudelstein, 113 
Squalodon, 881 
Squirrel, early forms of, 841, 868 
Stag, fossil, 898 
Stagonolepis, 763 
Stalactite, 112; formation of, 332, 353 
Stalagmite, 113 
Stars, composition of the, 11 
Stauria, 664 
Staurolite-slate, 122 
* 
Steam, solvent power of superheated, 298, 
300; in volcanic explosions, 218, 225, 
262 
_ Stegonodon, 880 
_ Stenaster, 669 
Steneosaurus, 776 
Stenopora, 753 
Stephanoceras (Ammonites), 786, 789*, 
TOL 
Stereognathus, 783 
Sternbergia, '755 
Stigmaria, 715, 728, 729*, 730*, 752 
Stigmariopsis, 733 
Stinkstone, 112 
Stiper-stone Group, 667 
Stocks and stock-works, 597 
Stomatopsis, 852 
Stone Age or Period, 902 
Stonesfield Slate, 782, 792 
Storm-beaches, 276, 437 
Storms, cause of, 317; destructive effects 
of on marine fauna, 607; transport of 
organisms by, 327 
Stramberg Limestone, 800 
Strata, alternations and associations of, 
490; relative persistence of, 491, 614; 
chronological value of, 495; ternary 
succession of, 498; groups of, 499 
grouped by lithological characters, 
499; and by fossils, 500; inclination 
of, 509; measurement of thickness of, 
514; curvature of, 514; crumpling of, 
519 
Stratification, forms of, 474; affords means 
of estimating the amount of displace- 
ment of rocks, 911; a guide to the 
amount of denudation, 911; influence of 
upon scenery, 922 ; 
