INDEX. 
racter of, 491, 614; classification of by 
ifr 616; formed in shallow water, 
Sedlitz, mineral water of, 351 
Seeds, transport of by wind, 326 
Seewenkalk, 830 
Seewenmercel, 830 
Seerevated structure, 90 
Segregation veins, 62, 90, 132, 556 
Seine, floods of ‘the, 359; ; ratio of dis- 
charge to rainfall, 361; terraces of the, 
3 
Semicrystalline structure, 103 
Semionotus, 775 
Semnopithecus, 880 
Senna, early forms of, 847 
Senonian, 814, 822, 827 
Sepia, 774 
Septarian nodules, 488 
Septarienthon, 859 | 
Septastrza, 789 
Sequanien, 797 
Sequoia, 803, 854*, 862, 871 
Sericite, 74 
Sericite-schist, 124 
Serpentine, characters of, 81; as an index 
of alteration, 107 
Serpentine-rock, 151 
Serpula, 795 
Serpulites, 664, 723 
Seve Group, 688 
Severn, annual discharge, 361; bore of, 
419 
pale. characters of, 161; formation of, 490, 
98 
Shaly structure, 88 
Shannon, slope of, 363 
Sheep, fossil, 880 
Sheets, intensive, 547 
Shell-banks, formation of, 464 
Shell-marl, 166 
Shell-mounds, 909 
Shell-sand, 167; cemented into solid stone, 
324, 438 
Shells, as proofs of upheaval, 277 
Shetlands, effects of lightning in, 318; 
contain no raised beaches, 19 
Shingle, 155; coarse forms of on sea-floor, 
435 
Shingle-beaches, 435, 437 
Shore (see Coast-line) 
Shore deposits, 437, 606; 
mains in, 606 
Shrew, earliest known forms of, 856 
Siberia, elevation of, 276, 280; 
rivers of, 369 
Sicily, Pliocene strata of, 877; mud- 
voleanoes of, 234 
Siderite, 83, 116; as a petrifying medium, 
~ 610 
Sigillaria, 708, 715, 728, 729*, 752; as a 
type-fossil, 615 
Silica in earth’s crust, 58, 65; in river 
water, 365, 453; in organisms, 168, 608 ; 
organic re- 
frozen 
965 
dissolved by organic acids, 463 ; dissolved 
by superheated steam, 298; deposited 
in the sea, 743; concretions of, 117, 
= considered as a petrifying medium, 
352 
Silicates, decomposition of, 333, 353; 
formed as decomposition products, 353 ; 
exist in soil, 347; forming on sea-floor, 
441, 470 
Siliceous composition, 90 
Siliceous deposits, 67, 117, 168, 354 
Siliceous sinter (see Sinter) 
Silicic acid, 60 
Silicification of organic remains, 610 
Silicon in earth’s crust, 57 
Silurian System, 661; salt and gypsum beds 
in, 661, 692, 693; volcanic rocks of (see 
Volcanic action) 
Silver, native, in fossil wood, 453 
Simocyon, 878 
Sinemurien, 798 
“Sinks” in limestone districts, 355 
Sinter, calcareous, 354; siliceous, 67, 117, 
354 
Siphonia, 804 
Siphonotreta, 665 
Sivatherium, 872, 880* 
Siwalik Group (Tertiary), 879 
Skaptar Jokull, eruption of, 224 
Skiddaw Slates, 670 
Slag (iron), contraction of in cooling, 295 
Slaggy structure, 89 
Slate as a geological term, 121 
Slaty fracture, 91 
Sleet, formation of, 329 
Slickensides, 504, 523, 592 
Slimonia, 664 
Slopes, deceptive angles of in mountains, 
39 
Smaragdite, 77 
Smell as a character of rocks, 93 
“Smilax, 832 
Snails, oldest known land-, 732, 749 
Snake River, basalt sheets of, 209, 256, 
565 
Snow, effect of on climate, 25; formation 
of, 329 ; geological action of, 403 
Snow-ice, 110 
Snow-line, 402 
Soda lakes, 395 
Sodium, 59 
Sodium Carbonate, chemical action of in 
water of bitter lakes, 399, 400 
Sodium Chloride in the air, 32; in sea 
water, 34, 59; as a rock, 85, 111; at 
volcanoes, 202 
Soil, characters of, 154; formation of, 321, 
339, 458 ; added to by deposit of dust, 
321, 339; influence of earth-worm on, 
339, 454; comparative fertility of, 339 ; 
fertilized by rain, 330; removal and 
renewal of, 540; supposed permanence 
of, 340; organic matter in, 347; evapo- 
ration from, 360 
