INDEX TO GEOLOGY 



Ochil Hills, their age, 234. 



Oil Shales, 41, 51. 



Old Red Sandstone, beautifully seen 

 at Siccar Point, 224— the Cale- 

 donian Old Red, points in the 

 history of, 237, 256— Orcadian 

 Old Red, 237— Upper Old Red, 

 its high antiquity, 237 — Con- 

 glomerate, 265. 



Ordovician, tuffs of the, 51 — rocks, 

 234- (fig. 2), 234. 



Orthoclase, 53. 



Pentland Hills, age and formation 



of, 230, 233, 234. 

 Phonolite, 53. 

 Pitchstone porphyry, 98. 

 Pterichthys, 228. 



Quartz, secondary, 238. 



Radiolaria, 254. 

 River terraces, 258. 



Schotts, or shallow salt lakes, 238. 



Siccar Point, Section through Old 

 Cambus (fig. 1), 228— the uncon- 

 formity at, represents a lapse of 

 178,000,000 years, 237— Siccar 

 Point and Cove, vertical section 

 shovcing strata (fig. 3), 239. 



Silurian Rocks, 224, 226, 265— 

 thickness of, 230 — their history, 

 230, 234— time required for their 

 deposition, 36 million years, 235 

 -Silurian Period, 256. 



Slates, red, 252. 



Time, lapse of, required by geo- 

 logical theory, 237. 

 Tuff,' 49, 51. 

 Turgite, 238. 



Volcanic Rocks of Cheviots and 



Pentlands, 233. 

 Volca"nic vents in the Lothians, 203. 



Whinstone. 23, 98. 



INDEX TO ZOOLOGY. 



Cervus Elaphus, 204. 



Red deer, 203, 204— origin of, 205. 

 Roe deer, 203, 204. 



Vegetable Caterpillar, 225. 

 Wapitis, 204. 



