INDEX. 



313 



Peyrehorade, numraulite limestone of, 

 198. 



Pkasianella and cast of same, 55. 



Phillips, Prof., on grooved surfaces of 

 faults, 78. 



, on joints in rocks, 141. 



, on the Coal strata, 243, 244. 246. 



, on the Mountain limestone, 253. 



, on Cambrian fossils, 270. 



Phillips, W., on composition of clays, 26. 



, on faults, 78. 



Pholadomya fidicula, 219. 



Phonolite, 101. 



Phyllade, 135. 



Physa, figures of, 45. 



Pid'dington, Mr., his analysis of the 

 water in the mud of the Hoogly 

 river, 58. 



Pmgel, Dr., on subsidence in Green- 

 land, 63. 



Pitchstone, 101. 



Plagiosloma, figures of, 183. 



Planorbis euomphalus, 45. 



Plants, fossil, of the Coal, 247. 



Plas-Newydd, changes caused by a 

 dike near, 107. 



Playfair, on rise of land in Sweden, 63. 



, his description of faults, 76. 



, on Huttonian theory, 154. 



Plesiosaurus, 228. 



Pliocene, term, whence derived, 166. 



, period, newer, strata of, near Na- 

 ples, 170. 



, in Norway, 171. 



, in S. America, 171. 



, in W. Indies, 171. 



, in valley of Rhine, 172. 



, in Great Britain and Ireland, 172. 



, (older) in England, 173. 



, volcanic rocks of, 275. 



, plutonic rocks of, why invisible, 



283 



Plutonic action, 145. 148. 



Plutonic rocks, described, 20. 118. 



, their relation to the volcanic, 20. 



, name whence derived, 20. 



, age of, how determined, 281. 



, Recent and Pliocene, why invisi- 

 ble, 283. 



, of different periods, 283. 



, relative age and position of. 284. 



. See also Hypogene rocks. 



Poikilitic group, 236. 



Polished surfaces of fissures and faults, 

 75. 78. 



Ponza islands, globiform pitchstone in, 

 113. 



Porcelain clay, 26. 



Porphyritic granite, 121. 



Porphyry described, 96. 101. 



Portland dirt-bed, 205, 206. 



Posidonomya minuta, 238. 



Pozzolana, composition of, 53. 



Predazzo, Oolite altered at, 288. 



Pressure, consolidating effects of, 54. 



B b 



Preston, tertiary strata at, 173. 



Prestwich, Mr., on the Coal strata, 245 



Primary fossiliferous strata, 264. 



, horizontal in Sweden, 269. 



Primary limestone, 134. 



Primitive or Primary, term, why erro- 

 neous, 23, 24. 154. 157. 



Producta, figures of, 241. 253. 



Protogine described, 122. 133. 135. 



Puddingstone described, 26. 



, of Hertfordshire, 52. 



, of Messenia, 199. 



Pumice described, 97. 101. 



Pupa muscorum, 46. 



Purbeck beds, 200. 



Puzzuoli, elevated marine strata at, 170. 



Pyrenees, bent strata in, 72. 74. 



, lamination of clay-slate in, 137. 



, rocks altered by granite in, 145. 



286. 



, chalk of, 195. 197. 



, trap rocks of, 278. 



Pyroxenic-porphyry, 101. 



Quadersandstein, 225. 

 Q'uadrumana, fossil, 180. 

 Quaquu-versal dip explained, 72. 

 Quartz rock or Quartzite described, 133. 

 Quartz veins, 129. 

 Quiriquina, island of, rocks shivered by 



earthquakes in, 83. 

 Quorra, R., delta of, 209. 



Radnorshire, trap rocks of, 280. 



Ramsholt, section at, 175. 



Rancie, altered Lias at, 145. 



Rathlin, dikes at, 108. 



Recent period, how separable from ter- 

 tiary, 169. 



, formations of, in different coun- 

 tries, 170. 172. 



, volcanic rocks of, 275. 



, plutonic rocks of, why invisible, 



283 



Red sandstone and marl, origin of, 242. 



, of different ages, 242. 



. See also Old, and New Red 



sandstone. 



Reptile, living marine, of the Galapa- 

 gos, 229. 



Reptiles, fossil, of the Wealden, 202. 

 210. 



, of the Lias, 227. 



, of the Muschelkalk, 238. 



, of the Magnesian Limestone, 242. 



Rhine, R., land shells drifted by, 43. 



, valley of, tertiary strata in, 172. 



Ribboned jasper, 144. 



Riley, Dr., on fossil reptiles, 242. 



Ripple mark, how formed (see Fig.), 33. 



Rock, term defined, 14. 



Rocks, all divisible into four contempo- 

 raneous classes, 15. 22. 



, aqueous, described, 15. 25. 



, volcanic, described, 18. 89. 



