INDEX. 
G37 
STOILY. 
Sicily, fauna and flora of, older than the 
country itself, 207. 
-, newer Pliocene strata of, 204. 
-, subterranean igneous action iti, 569. 
-, undulating gypseous marls of, 86. 
-, volcanic dikes of, 531. 
Sidlaw Hills, trap of, 548. 
Sigillaria in coal-measures, 380,411, 425. 
Sigillaria Imvigata, coal-measures, 426. 
Siliceous limestone defined, 37. 
Silurian, derivation of the name, 458. 
-granite of Norway, 573. 
-, metamorphic, of North Highlands, 
601. 
-rocks, classification of, 458. 
-strata of the continent of Europe, 
477. 
-strata of United States, 478. 
-volcanic rocks, 548. 
Siphonotretaunguiculata, obolns grits, 478. 
Siwalik Hills, fresh-water deposits of, 226. 
Skaptar Jokiil, flow of lava from, 523. 
Skye, hypersthene rocks of, 491. 
-, Isle of, Miocene syenite of the, 568. 
-, trap dike in, 514. 
Slaty cleavage, 588. 
Slickeu-sides, in opposite walls of veins, 
608. 
-, term defined, 87. 
Smilax sagittifera, CEningen, 222. 
Smith, Mr. W., on White Lias bed, 366. 
Snowdon, volcanic tuffs of, 549. 
Soissonnais sands, 275. 
Solenastrcea celkdosa, Brockenhurst, 257. 
Solenhofen stone, fossils in the, 337. 
Solfatara, decomposition of rocks in the, 
586. 
Somma, cone and dikes of, 526. 
Sop with, Mr. T., models of outcrop of 
strata, 85. 
Sorby, Mr., on action of water in meta¬ 
morphism, 585. 
-, on glass cavities in quartz, 555. 
-, ou mechanical theory of cleavage, 
592. 
-, on ripple-marks in mica schist, 596. 
South Joggins, section of cliffs at, 410. 
Spalacotherium, Pnrbeck, 346. 
Spatangus racliatus^ Chalk, 284. 
-with serpula attached, 49. 
Species, gradual change of, 139. 
-older than the laud they inhabit, 207. 
-, similarity of conditions causing re¬ 
appearance of, 311. 
Specific gravity of basalt and trachyte, 
504. 
Speer and Rigi, Lower Miocene of the, 
235. 
Speeton Clay, 311. 
Sphcerexocfius miru,% Silurian, 467. 
Sphcerulites agaridformis, White Chalk, 
306. 
-of volcanic minerals, 499. 
Sjyhenophgllum erosum^ Coal, 425. 
Splienoigteris gracilis^ Hastings sands, 318. 
Spheroidal concretions in limestone, 64. 
Spimla of sponge^ Atlantic mud, 288. 
ISpinfera disjmicta, Devonian, 450. 
- alata^ Permian, 388. 
- mucronata, 454. 
- trigonalis, and S. glabra, 434. 
Spiriferina Walco.tti, tias, 355. 
SUESS. 
Spirolina stenostoma, Eocene, 275. 
Spirorbis carbonariu.% coal-measures, 405. 
Spondylus spinos^is, White Chalk, 294. 
Sponge in flint f rom White Chalk, 
Sponges, vitreous, in the chalk, 291. 
Springs, mineral of Auvergne, 604. 
Staffa, age of columnar basalt of, 539. 
Stalactite, origin of, explained, 156. 
Starfish in Silurian strata, 472. 
Stations of species afi’ecting distribution 
of fossils, 354. 
Stauria astrceiformis, 431. 
Stereognathus of Stouesfield, 348. 
Sternberg, Count, on insects in coal, 405. 
Stigm.aria attached to trunk of Sigillaria, 
427. 
-in coal-measures, 398, 411, 426. 
- ficoides and surface showing tubercles, 
Coal, 427. 
Stilbite, 500. 
Stiper-Stoues or Areuig Group, 475. 
Stockwerk, assemblage of veins, 605. 
Stouesfield slate, mammalia of the, 345. 
Strata, term defined, 27. 
--, alternations of fresh-water, and shal¬ 
low and deep-sea, 108. 
-, alternations of marine and fresh-wa- 
ter, 73. 
-, curved, inclined, and vertical, 73. 
-, apparent horizontality of inclined, 81. 
-, contorted in drift, 178. 
-, contortion of, in Cyclopean Isles, 530. 
-, general table of fossiliferous, 131. 
-horizontality of, 40, 
-, origin of metamorphic, 579, 
-, outcrop of, 83. 
-, overlapping, 95. 
-repeated by being doubled back, 87. 
-, slow growth of, attested by fossils, 
47-50. 
-of organic origin, 51. 
-, tests of age of, 123. 
-, uncon for mability of, 94,138. 
-, vast thickness of, not forming high 
mountains, 109-113. 
Stratification, diagonal or cross, 42, 44. 
-, different forms described, 39. 
- of metamorphic rocks considered, 
580. 
Stratified rocks, composition of, 35. 
StricB, production of, 168. 
Strickland, Mr., on thickness of the Trias, 
369. 
Stricklandinia lirata, 469. 
Strike, term explained, 80. 
Stringocephalus Burtini, 452. 
Stromboli, lava of, 566. 
Strophomema depressa, Wenlock, 466. 
- grandis, 471. 
Studer, Mr., on gneiss of the Jungfrau, 599. 
Subacrial denudation, average aunuid 
amount of, 113. 
Subapennine beds, proportion of recent 
species in, 143. 
-strata, Older Pliocene, 208. 
Submarine denudation, 105. 
Subsidence of landmustpreponderate over 
upheaval, 116. 
Succinea amphibia, 55. 
- elongata, 155. 
Suess, M , on fossils of St. Cassiaii beds, 
376, 377. 
