Sabal major, 309.
Sabre-toothed Tiger, 322, 331.
Saccammina, 172.
Saccosoma, 232.
Salamanders, 189, 313.
Salina Group, 117.
Salix, 262; Meeki, 263.
Salmonidœ, 276.
Sao hirsuta, 85.
Sassafras cretacea, 263.
Sauropterygia, 219.
Scalaria, 271, 293; Grœnlandica, 338.
Scaphites, 272, 273; œqualis, 274.
Schizodus, 198, 211.
Schoharie Grit, 135, 137.
Scolecoderma, 82.
Scoliostoma, 213.
Scolithus, 82; Canadensis, 83.
Scorpions of the Coal-measures, 181.
Scorpion-shells, 271.
Screw-pines, 230.
Scutella, 311; subrotunda, 312.
Sea-cows (see Sirenia).
Sea-lilies (see Crinoidea).
Sea-lizards (see Enaliosaurians).
Seals, 322.
Sea-mats and Sea-mosses (see Polyzoa).
Sea-shrubs (see Gorgonidæ).
Sea-urchins (see Echinoidea).
Sea-weeds, 80, 81, 83, 97, 136, 164, 261.
Secondary period, 44.
Sedimentary rocks, 15.
Semnopithecus, 322, 331.
Septaria, 31.
Sequoia, 306, 309, 310; Couttsiœ, 309; gigantea, 309; Langsdorffii, 309.
Serolis, 84.
Serpents (see Ophidia).
Serpulites, 123.
Sewâlik Hills (see Siwâlik Hills).
Sheep, 355.
Shell-sands, 19.
Sigillaria, 168; Grœseri, 168.
Sigillarioids, 136, 168, 170, 196.
Silicates, infiltration of the shells of Foraminifera by, 34, 74.
Siliceous rocks, 20, 32.
Siliceous Sponges, 265.
Silicification, 13, 14.
Silurian period (see Lower Silurian and Upper Silurian), 90-114, 115-132.
Simosaurus, 219; Gaillardoti, 219.
Siphonia, 264; ficus, 265.
Siphonostomatous Univalves, 237, 271, 293.
Siphonotreta, 110.
Sirenia, 299, 320; of the Eocene, 299; of the Miocene, 315.
Siren lacertina, 200.
Sivatherium, 318; giganteum, 319.
Siwâlik Hills, Miocene strata of, 307.
Skiddaw Slates, 101.
Sloths, 315, 349-351.
Smilax, 308.
Smithia, 173.
Snakes (see Ophidia).
Soft Tortoises, 296.
Solarium, 271.
Solenhofen Slates, 228.
Solitaire, 346, 348.
Spalacotherium, 254.
Spatangus, 311.
Sphœrospongia, 139.
Sphagodus, 130.
Sphenodon, 218.
Sphenopteris, 136, 165, 196.
Spiders of the Coal-measures, 181.
Spider-shells, 237.
Spindle-shells, 237.
Spirifera, 125, 147, 184, 198, 234; crispa, 127; disjuncta, 147; hysterica, 126; mucronata, 147; Niagarensis, 127; rostrata, 235; sculptilis, 147; trigonalis, 185.
Spiriferidœ, 147.
Spirophyton cauda-Galli, 135, 164.
Spirorbis, 123, 143, 178; Arkonensis, 144; Carbonarus, 178; laxus, 144; Lewisii, 123; omphalodes, 144; spinulifera, 144.
Spirulirostra, 312.
Spondylus, 269; spinosus, 270.
Sponges, of the Cambrian, 81; of the Lower Silurian, 98; of the Upper Silurian, 119; of the Devonian, 139; of the Carboniferous, 171; of the Permian, 197; of the Trias, 209; of the Jurassic, 230; of the Cretaceous, 264, 265.
Spongilla, 197.
Spongillopsis, 197.
Spongophyllum, 173.
Spore-eases, of Cryptogams in the Ludlow rocks, 118; in the Coal, 163.
Squirrels, 322.
Stagonolepis, 218.
Staircase-shell, 271.
Stalactite, 21.
Stalagmite, 21.
Star-corals, 231.
Star-fishes, 105, 120, 210.
St Cassian Beds, 205, 206.
Stephanophyllia, 266.
Stereognathus, 253, 254.
Stigmaria, 169; ficoides, 169.
Stonesfield Slate, 227; Mammals of, 253.
Strata, contemporaneity of, 44.
Stratified rock, 15-18.
Streptelasma, 105.
Streptorhynchus, 198.
Stromatopora, 98, 99, 118, 139; rugosa, 99; tuberculata, 140.
Strombodes, 119; pentagonus, 104.
Strombus, 271.
Strophalosia, 198.
Strophodus, 255.
Strophomena, 109, 110; alternata, 110; deltoidea, 109; filitexta, 110; rhomboidalis, 147, 148; Subplana, 127.
Sub-Apennine Beds, 325.
Sub-Carboniferous rocks, 158, 161.
Succession of life upon the globe, 367-374.
Suida, 302, 317, 329.
Sulphate of lime, 22.
Sus Erymanthius, 317; scrofa, 354.
Synastrœa, 209.
Synhelia Sharpeana, 266.
Synocladia, 198; virgulacea, 198.
Syringopora, 119, 173; ramulosa, 174.

Tabulate Corals, 104; of the Lower Silurian, 105; of the Upper Silurian, 142; of the Devonian, 142; of the Carboniferous, 172; of the Permian, 197.
Talpa Europœa, 336.
Tapiridœ, 300.
Tapirs, 300.
Tapirus Arvernensis, 327.
Taxocrinus tuberculatus, 122.
Taxodium, 262, 308, 310.
Teleosaurus, 251.
Teleostean Fishes, 150; of the Cretaceous, 276.
Telerpeton Elginense, 218.
Tellina proxima, 338.
Tentaculites, 129, 148; ornatus, 129.
Terebra, 293.
Terebratella, 268, Astleriana, 268.
Terebratula, 184, 234; digona, 235; elongata, 168; hastata, 185; quadrifida, 235; sphœroidalis, 235.
Terebratulina, 268; caput-serpentis, 268; striata, 268.
Termites, 311.
Terrapins, 280, 296.
Tertiary period, 44, 284-287.
Tertiary rocks, classification of, 284-287.
Testudinidœ, 313.
Tetrabranchiate Cephalopods, 112; of the Cambrian, 89; of the Lower Silurian, 112-114; of the Upper Silurian, 130; of the Devonian, 149; of the Carboniferous, 186, 187; of the Permian, 199; of the Trias, 212; of the Jurassic, 237-239; of the Cretaceous, 272-274; of the Eocene, 294; of the Miocene, 312.
Textularia, 22, 264, 311; Meyeriana, 311.
Thanet Sands, 287, 288.
Theca, 88, 111, 129.
Theca Davidii, 88.
Thecidium, 213.
Thecodont Reptiles, 218.
Thecodontosaurus, 200, 218; antiquus, 219.
Thecosmilia annularis, 231.
Thelodus, 131.
Theriodont Reptiles, 202, 220.
Thylacoleo, 349.
Tile-stones, 116.
Titanotherium, 316.
Toothed Birds, 281-283.
Tortoises, 202, 296.
Tragoceras, 318.
Travertine, 21.
Tree-Ferns, of the Devonian, 136; of the Coal-measures, 164.
Tremadoc Slates, 77-79.
Trematis, 110.
Trenton Limestone, 95, 96.
Trianthrus Beckii, 107.
Triassic period, 203; rocks of, in Britain, 204; in Germany, 204; in the Austrian Alps, 205; in North America, 205; life of, 206-224.
Triconodon, 254.
Trigonia, 235, 255, 269.
Trigoniadœ, 198, 211.
Trigonocarpum, 170; ovatum, 170.
Trilobites, 84-87; of the Cambrian, 85, 87; of the Lower Silurian, 107, 108; of the Upper Silurian, 123, 124; of the Devonian, 144, 145; of the Carboniferous, 179.
Trimerellidœ, 127.
Trinucleus, 108; concentricus, 107.
Trionycidœ, 296.
Triton, 293.
Trochocyathus, 266.
Trochonema, 129.
Trogontherium, 361; Cuvieri, 336, 361.
Trumpet-shells, 293.
Tulip-tree, 262, 308.
Turbinolia sulcata, 292.
Turbinolidœ, 292.
Turrilites, 272, 273; catenulatus, 274.
Turritella, 271, 293.
Turtles, 202, 251, 280, 296.
Typhis tubifer, 293.

Ullmania selaginoides, 197.
Unconformability of strata, 48.
Under-clay of coal, 162.
Ungulata, of the Eocene, 300-303; of the Miocene, 315-319; of the Pliocene, 327-329; of the Post-Pliocene, 353-357.
Uniformity, doctrine of, 5-7.
Unio, 250.
Univalves (see Gasteropoda).
Upper Cambrian, 77-79; Chalk, 259; Cretaceous, 257, 259; Devonian, 135; Eocene, 287, 288; Greensand, 258; Helderberg, 135; Laurentian, 66; Llandovery, 115; Ludlow rock, 116; Miocene, 305; Oolites, 227; Silurian period, 115; rocks of, in Britain, 115, 116; in North America, 116-118; life of, 118-131.
Ursus arctos, 359; Arvernensis, 339; ferox, 359; spelœa, 360.
Ursus, 336, 356.

Valley-gravels, high-level and low-level, 339-341.
Vanessa Pluto, 312.
Varanidœ, 202.
Vegetation (see Plants).
Ventriculites, 264, 265; simplex, 265.
Venus's Flower-basket, 265.
Vermilia, 197.
Vespertilio Parisiensis, 304, 305.
Vicksburg Beds, 289.
Vines, 306, 309, 310.
Vitreous Sponges, 264.
Voltzia, 208; heterophylla, 209.
Voluta, 271, 293; elongata, 271.
Volutes, 271, 293, 312.

Walchia, 196, 197; piniformis, 196.
Walrus, 322.
Wealden Beds, 257.
Wellingtonia, 309, 310.
Wenlock Beds, 115, 117; Limestone, 115; Shale, 115.
Wentle-traps, 271.
Werfen Beds, 205, 206.
Whalebone Whales, 299, 315.
Whales, 299, 315.
Whelks, 237.
White Chalk, 259; structure of, 21, 22; origin of, 23, 263.
White Crag, 324.
White River Beds, 307.
Wild Boar, 354.
Williamsonia, 230.
Winged Lizards (see Pterosauria).
Winged Snails (see Pteropods).
Wing-shells, 271.
Wolf, 336, 360.
Wolverine, 360.
Wombats, 348.
Woolhope Limestone, 115.
Woolly Rhinoceros, 339, 341, 344, 353.
Woolwich and Reading Beds, 287.
Worm-burrows, 82, 83, 123.

Xanthidia, 138, 161.
Xenoneura antiquorum, 145.
Xiphodon, 303.
Xylobius, 182; Sigillariœ, 182.

Zamia spiralis, 208.
Zamites, 208, 230, 310.
Zaphrentis, 105, 119, 142, 173; cornicula, 141; Stokesi, 104; vermicularis, 174.
Zeacrinus, 175.
Zechstein, 194.
Zeuglodon, 299, 315; cetoides, 200, 300.