314 



INDEX. 



Rocks, pi Li tonic, described, 118. 



, metamorphic, described, 131. 



, how to detect alumina or lime in, 



23, 27. 



, hardened by exposure to air, 52. 



, their particles re-arranged by 



chemical action, 53. 



, transported by ice, 86. 



, how to be studied, 94. 



, altered by dikes and granite, 104. 



107. 123. 143. 145. 286. 294. 

 , different ages of the four great 



classes of, 151. 159. 271. 281. 294. 



, classification of; 15. 24. 157. 163. 



Rose, G., on hornblende and augite, 93. 

 , on composition of volcanic rocks, 



99, 100, 101. 

 Ross-shire, denudation in, 81. 

 Rostellaria macroptera, 179. 

 Rother, R., buried ship in old channel 



of, 172. 

 Rothliegendes, 240. 

 Roththai, section m the, 298. 

 Rouen, chalk needles near, 194. 

 Rubble explained, 83. 



St. Abb's Head, curved strata near, 66. 

 St. Etienne, vertical trees in Coal stra- 

 ta at, 258. 

 St. Helena, basaltic dike in. 111. 

 Salbands, 105. 



Salisbury Craig, altered strata in, 109. 

 San Caterina, bent strata near, 73. 

 Sandstone described, 25. 

 San Lorenzo, isle of, Recent strata in, 

 171. 



Sat!el, section on the, 298. 



Sauroid fish of the Coal, 246. 



Saussnre on vertical conglomerates, 64. 



Savi, M., on metamorphic rocks, 295. 



Saxony, aqueous strata rendered colum- 

 nar by basalt in, 140. 



Scania, sinking of land in, 63. 



Schorl, analysis of, 102. 



Schorl rock described, 122. 



Scoresby, on rents in icebergs, 140. 



Scorias described, 97. 101. 



Scrope, Mr., on Auvergne volcanos, 91. 



, on volcanic rocks, 98. 113. 275. 



Sea, proofs that it has not sunk, but 

 that the land has been raised, 61. 



Sea-urchins, figures of 37. 



Seale, Mr., on dikes in St. Helena, 111. 



Sedgwick, Professor, on garnets in al- 

 tered rocks, 107. 



, on changes caused by trap dike, 



108. 



, on intrusion of trap, 110. 



, on granite veins, 126. 



, on stratification, joints, and cleav- 

 age, 137, 138. 142. 



, on lower New Red sandstone, 239. 



, on the Magnesian limestone, 53. 



241. 



, on the Coal, 244. 



• , on Cambrian system, 264. 270. 281. 



Sedgwick, Professor, on granite of 

 Dartmoor, 288. 



, on granite of Brora, 291. 



, on geology of Arran, 294. 



Segregation, veins formed by, 129. 



Seine, chalk needles in valley of, 194. 



Semi-opal, infusoria fossil in, 40. 



Serpentine, 101, 102. 135. 



SerpuloB on fossils, prove slow deposi- 

 tion of strata, 36. 



Sewalik hills, fossils of the, 180. 



Shale defined, 26. 



Shells, marine, rules for recognizing, 44. 



, freshwater {seefgures), 44, 45, 46. 



, common to rivers and the sea, 46. 



, amphibious, 46. 



, terrestrial (see figures), 46. 



, inferences drawn from the shape 



of the mouths of, 46, 47. 

 Sheppey, isle of, fossils, 180. 

 Shetland, granites of, 126. 

 Ships, fossil, 172. ^ 

 Sicily, tertiary strata of, 62. 

 Sidlaw hills, section of the, 65. 



, trap rocks of, 279. 



Sigillarice, figures of, 248. 



, erect position of in Coal strata, 259. 



Silex, in solution, source of, 59. 

 Siliceous limestone described, 27. 

 Silurian strata, origin of name, 264. 



, table of succession of, 265. 



, Upper, fossils ofi 265. 



, Lower, fossils of, 267. 



, Lower, trap rocks of, 280. 



, in Norway and Sweden, 62. 267 



269. 



, horizontal, 269. 



, in N. America, 268. 



, granite altering, 288. 



Skaptar Jokul, eruption of, 274. 

 Sky, trap dikes in, 104, 105. 



, columnar basalt of^ 111. 



, rocks altered by trap in, 109. 



Slaty cleavage, 137. 141. 

 Slickensides, 75. 78. 

 Snowdon, fossils of, 270. 

 Sodertelje, recent strata at, 170. 

 Solenhofen fossils, 221. 

 Solfatara, rocks of, decompose, 147. 

 Sorgenfri, dike at, 106. 

 Sorting power of water, 30. 

 Spatangiis, figures of, 37. 

 Sphceruliles agariciformis, 197. 

 SpheJiopteris, figures of, 204. 248. 

 Spirifera, figures of, 241. 253. 

 Sponge in flint, 185. 

 Spongilla in tripoli, 40. 

 Springs, calcareous, 50. 302. 

 StafTa, rock of, volcanic, 19. 

 Stammerham, cracks in clay at, 208. 

 Stations of species, 217. 

 Steatite. 102. 



Steeple Ashton, fossil coral from, 215. 

 Sternberg on fossil coal plants, 247. 

 Sligmarice, figures of, 252. 

 Stirling Castle, rock of altered, 109. 



