INDEX. 
633 
OBSIDIAN. 
Obsidian, 505. 
Oceanic areas, permanence of, 117. 
(Euingen, Upper Miocene beds of, 215. 
Oeynliausen, M. von, on Cornish granite 
veins, 560. 
Ogj/gia Buchii, 474. 
Oldhamia radiata : 0. antiqua, 4S7. 
Old Eed Sandstone, Upper, 440* 
--, Middle, with ftsh, 443. 
-, Lower, 446. 
-, trap of the, 547. 
-, classification of, 439. 
Olenus micrurus, 4S4. 
Oligocene, term for Lower Miocene, 230, 
244. 
Oligoclase, 499, 500. 
Oliva Dufresnii, Bolderberg, Belgium, 224. 
Olivine, 499. 
Omphyma turMnatuw,^ Silurian, 466. 
Onchiis tenuistriatus, Silurian, 460. 
Oolite, classification and physical geogra¬ 
phy of the, 321. 
-defined, 37. 
-, Inferior, fossils of the, 349, 350. 
-and Lias, origin of the, 364. 
-and Chalk, Palaeontological break be¬ 
tween, 338. 
Oolitic strata, palaeontological relations of, 
351. 
-volcanic rocks, 545. 
Ophioderma tenuibrachiata^ Lias, 357. 
Oppel on zones of Lias, 353. 
Orbigny, Alcide de, on foraminifera of Vi¬ 
enna basin, 225. 
-, on orbitoidal limestone, 279, 
-, on Pisolitic limestone, 285. 
-, on Senonian, 302. 
Oreodaphne Heerii, Italian Pliocene, 209. 
Organic remains, mineralization of, 65. 
-, tests of age of strata, 125. 
-, tests of age of volcanic rocks, 522, 
-■, geological provinces of, 127. 
Oriskauy Sandstone, 478. 
Orthis elegantula, Ludlow, 46. 
- grandis, Caradoc beds, 470. 
- tricenaria^ Bala beds, 470. 
- vespertilio, Bala beds, 470. 
Orthoceras duplex, 474. 
- Ludcnse, Silurian, 463. 
- laterale, 436. 
- ventricosum, Silurian, 462. 
Orthoclase, 499, 500. 
Orthoclastic feldspars, 501. 
Osborne or St. Helen’s series. Eocene, 255. 
Osteolepis, Old Red Sandstone, 444. 
Ostraceon, spine of, Bracklesham, 261. 
Ostrea acuminata. Fuller’s earth, 349. 
- carinata. Chalk marl, 300. 
- columba, Chloritic sand, 800. 
- gregarea, Coral Rag, 339. 
- deltoidea, Kimmeridge clay, 336. 
- distorta. Middle Purbeck, 324. 
- expansa, Portland sand, 336. 
- Marshii, Oolite, 351. 
- vesicularis. Chalk, 295. 
Otodus obliquus, Bracklesham, 262. 
Outcrop of strata, 83. 
Overlapping strata, 95. 
Owen, Professor, on Archaeopteryx, 337. 
-, on Eocene Zeuglodon, 279. 
-, on foot-prints in Trias, 382. 
-, on fauna of Sheppey, 265, 267. 
27* 
PERN A MTJLLETI. 
Owen, Prof., on Gastornis Parisiensis, 276. 
-, on Labyrinthodon, 370. 
-, on mammalia of Stonesfield, 347. 
-, on Purbeck mammalia, 326, 328. 
-, on reptiles of coal, 407,414. 
-, on zoological provinces of extinct 
animals, 160. 
Ox, tooth of (recent), 165. 
Oxford Clay, thickness and fossils of, 340. 
PAGE AM, erratic block at, 182. 
Palceaster asperimus, 472. 
Palmchinusgigas. Mountain Limestone, 43. 
Palmocoma tenuibrachiata. Lias, 357. 
Palceoniscus, Permian fish, 389. 
- comptus, P. elegans, P. glaphyrus, 390. 
Palceotherium magnum, 254. 
Palceophis iyphoeus, Bracklesham, 261. 
Palaeozoic or Paleozoic, term defined, 123. 
-Plutonic rocks, 572. 
-rocks, 458. 
-type of corals, 431. 
Palagonia, dikes of lava in, 531. 
Paleolithic era, 147,149. 
-, alluvial deposits of, 150. 
Palm in Swiss Miocene, 237. 
Palma, volcanic crater of, 497. 
Paludina lenta, Hempstead beds, 55, 245. 
- orbicularis, Bembridge, 253. 
Paradoxides Bohemicus, 488. 
- Davidis, Lower Cambrian, 485. 
Parallelism of folded strata for long dis¬ 
tances, 93. 
Paris basin, Tertiary group first studied in, 
141. 
-, Tertiaries of the, 270. 
Parka decipiens, “Old Red,”448. 
Parkfield Colliery, ground-plan of, 400. 
Patagonia, strata of, rich in soda, 687. 
Patella rugosa. Great Oolite, 345. 
Paterson, Dr., on angiosperm of the Coal, 
429. 
Peach, Mr. C., cited, 601. 
-, Pteraspis, found by, 443. 
Pearl stone, 505. 
Pebbles in mineral veins, 608. 
-in chalk, 292. 
Pecopteris elliptica. Coal, 421. 
Pecten Beaveri, White Chalk, 294. 
- cinctus, Neocomian, 312. 
- islandicus, Scotch Drift, 176. 
- jacobceus, in tertiary of Sicily, 206. 
- 'quinque-costatus, 300. 
- Valoniensis, Rheetic beds, 366. 
Pegmatite, 553. 
Penarth beds, 366. 
Pengelly, Mr., on Bovey Tracey lignite, 
246. 
-, on flint-knives of Brixham Cave, 157. 
Pentacrinus Briareus, Lias, 357. 
Pentamerus Knightii, Aymestry, 461. 
- oblongus, and P. lirata, 469. 
Pentland Hills, volcanic rocks of the, 54S. 
Perigord cave, carving of mammoth in, 150. 
Permanence of continents and oceans, 117. 
Permian Flora, 392. 
-of Germany, 393. 
-strata, thickness of, in north of En¬ 
gland, 386. 
-, Ui)per and Middle, 386, 387. 
-, Lower, 390. 
Pcrna Mullcti, Neocomian, 310. 
