104 



INDEX. 



Secondary rocks, volcanic, of many different 



ages, 335 

 Secondary fresh-water deposits why rare, 



330 



Secondary periods, duration of, 328 

 Sed?wick, Professor, on diluvial waves, 

 101, 272 



on the tertiary formations of Styria, 



213, 214 



on the volcanic rocks of Styria, 224 



on the Isle of Wight, 281, 315 



on synclinal lines, 293 



. on the theory of M. Elie de Beau- 

 mont, 347 



on the Cornish granite veins, 355 



on garnets in altered shale, 369 



Sediment, changes in the distribution of, 

 which would take place on the filling up 

 of large lakes, 27 



Sedimentary deposition, causes which oc- 

 casion the shifting of the areas of, 26 

 Sedimentary rocks, distinction between 



volcanic and, 10 



Seguinat, Montagne de, lamination of 

 clay-slate in the see wood-cut, No. 89, 

 366 



Selenite found in clay at the foot of Etna, 77 

 Septaria of the London clay described, 279 

 Serre del Solfizio, sections of buried cones 

 in the cliffs of, 88 



dikes at the base of see wood-cut 



No. 19, 90 



Serres, M. Marcel de, on the drifting of 

 land shells to the sea by the Rhone, 48 



on the tertiary strata of Montpellier, 



215 



. on the fossil insects of Aix, 277 

 Sicily, geological structure of, 22, 63 

 dip and direction of the newer Plio- 

 cene strata of, 73 



origin of the newer Pliocene strata 

 of, 103 



form of the valleys of, 109 



r.o peculiar indigenous species found 



in, 115 



breccias containing bones of extinct 

 animals in caves in, 139 



alluviums of the newer Pliocene, 



period in, 151 



fossil shells of see Tables, Appen- 

 dix I. 



number of living species in the fos- 

 sil shells of see Appendix I., 47 



number common to Italy and, ib. 47 

 - number common to Italy, the Crag 



and, ib. 47 



number of species proper to, ib. 47 



Shells, tables of fossil (see Appendix,) 49 

 characteristic tertiary (see Plates,) 



50 

 necessity of accurately determining 



the species of, 50 



Shells, recent, numerical proportion of in 

 the different tertiary periods, 58 



number of species of, found both 



living and fossil, 394 



fossil tertiary, number examined to 



construct the tables, 394 



fossil, number common to all the 



tertiary periods, Appendix I., 50 



li v i n gj number of those found in a fos- 

 sil state in all the tertiary periods, ib. 50 



geographical distribution of those 



species which have their fossil analogues, 

 ib. 51 



Sherringham, sections in the cliffs east of 

 see wood-cuts, Nos. 39 and 40, 178, 

 179 



rapid waste of the cliffs at see sec- 

 tion, wood-cut No. 72, 297 



Shetland, action of the sea on the coast of, 

 146 



granites of different ages in, 357 



passage of trap into granite in, 362 



Siebengebirge, volcanic phenomena of the, 

 198 



Sienna, Subapennine strata near the town 

 of, 160 



microscopic fossil shells very abun- 



dant 



163 



list of fossil shells from Appendix 



II., 59 

 Siliceous schist, clay converted into by 



lava, 70, 81 

 Silvertop, Col., on the tertiary strata of 



Spain, 170 



Simeto, plain of the, 76 

 Sioule, river, ravines cut through lava-cur. 



rents by the, 265 

 Sky, age of the granite of, 358 

 Smyth, Capt. W. H., his drawing of the 



Isle of Cyclops see wood-cut No. 14, 



79 



on the extinct volcanos of Sardi- 

 nia, 193 

 Somma, escarpment of, 84, 85, 87, 96 



changes caused by dikes in the, 91 



dikes of, 121 



minerals found in, 121 



parallelism of the opposite sides of 



the dikes of, 122 

 varieties in the texture of the dikes 



of, 124 

 Somma and Vesuvius, differences in the 



composition of, 120 

 Sortino, great limestone formation seen in 



the valleys of, 64 

 bones of extinct animals in caves 



near, 139 



South Downs, chalk ridge called the, 287 

 section from to the North Downs 



across the Weald Valley see wood-cuts 



No. 63 and 64, 288 

 highest point of the, 288 



