900 



INDEX. 



Pierre a-bot, 533. 

 Pierre group, 456. 

 Pillared rocks, 168. 

 Piloceras, 250. 

 Pine, 594, 609. 

 Pinites, 371. 



Brandlingi, 331, 

 Pinna, 385. 



affinis, 518. 



folium, 429. 



Missouriensis, 303. 



peracuta, 342. 

 Pinnotheres, 372. 

 Pinnularia, 348. 



aequalis, 634.* 



borealis, 634* 

 ■ peregrina, 134* 496* 



viridis, 634 * 



viridula, 634.* 

 Pinus abies, 362, 365. 



larix, 362. 



picea, 362. 



Strobus, 134 * 

 Pisolite, 86. § 

 Pistosaurus, 428, 429. 

 Pitch of rivers, 638. 

 Pitchstone, 77. § 

 Pith of Conifers, 331. 

 Pithecus, 520. 

 Pittsburg coal-bed, 312, 313, 



321 331 

 Placoderms,'264,§* 284. 

 Placodus, 429. 



impress us, 429. 

 Placuna scabra, 456. 

 Placunopsis, 342. 

 Plagiaulax, 428,§ 448. 



Becklesii, 450. 



minor, 450. 

 Plagiostoma gigantea, 438,* 448. 

 Plains, 15. 



Plan in the earth's features, 46. 

 Pliinerkalk, 470. 

 Plane tree, 458, 497, 515. 

 Planing of rocks. See 



Scratches. 

 Planorbis, 450, 482, 617. 



bicarinata, 550. 



discus, 519. 



euomphalus, 519. 

 Plant-beds, 514, 515, 546. 

 Plant-growth of the Carbonif- 

 erous, 353 

 Plant kingdom, 1. 

 Plantless zone, 609. 

 Plant-remains in coal, 317. 

 Plants, subdivisions of, 133. § 



affected by climate, 353. 



and animals, distinctions of, 

 115§ 



in Archaean, 157. 



in Carboniferous, 321, 331, 

 347, 348 * 



in Catskill,280. 



in Chemung, 277, 278. 



in Corniferous, 527 



in Cretaceous, 458, 471. 



in Devonian, 283. 



in Hamilton, 268. 



in Jurassic, 436. 



in Ludlow, 245. 



in Oriskany, 242. 



in Permian, 370. 



in Silurian, 169, 176, 177, 197, 

 223, 242, 252. 



in Tertiary, 496, 514. 



in Triassic, 407. 



phosphoric acid in ash of, 61. 



protective effects of, 606. 



Plants, rank of earliest, 242, 



252. 

 Plasticity in ice, 695. 

 Platanus, 459, 497, 498. 



aceroides, 459, 498, 514. 



Guiielmae. 498, 499. 



Heerii, 460. 



Raynoldsii, 498. 

 Plateaus, 16, § 21. 

 Platephemera antiqua, 273,* 



274. 

 Plattendolomit, 369. 

 Platyceras, 240, 243,§ 303. 



angulatum, 227,* 229. 



dumosum, 260 * 261. 



primordiale, 178. 



ventricosum, 240, 274. 

 Platycnemic tibia, 577. 

 Platycrinus, 240. 303. 



Saffordi, 298,*' 303. 

 Platygnathus, 286. 

 Platygonus Condoni,511. 

 Platyostoma, 240, 243. 



Niagarensis, 227,* 229. 

 Platyrrhines, 610. 

 Platyschisma helicites, 250. 

 Platysomus, 372. 



gibbosus, 372. 



macrurus, 372. 

 Platytrochus speciosus, 466. 

 Plectrodus mirabilis, 246,* 247. 



pustuliferus, 247. 

 Pleistocene, 513. 

 Plesiosaurus, 339,§ 428. 429, 

 443, 444, 449, 450, 464, 474, 

 475, 476, 484. 



costatus, 428. 



dolichodeirus, 442,* 444, 449 



Hawkinsii, 428. 



macrocephalus, 443,* 444, 

 449. 

 Pleta, 163, 208. 

 Pleurocystis squamosus, 199,* 



203! 

 Pleurodictyum problematicum, 



284. 

 Pleurodonts, 338. § 

 Pleuromya unioides, 433. 

 Pleurophorus subcuneatus, 



368.* 

 Pleurosigma angulatum, 134.* 

 Pleurotoma, 611. 

 Pleurotoma attenuata, 518. 



first of, 477, 483 

 Pleurotomaria, 284, 303, 385. 



Americana, 206. 



Anglica, 448. 



Calcifera, 189, 192. 



calyx, 191. 



carbonaria, 342. 



carinata, 308. 



elongata, 449 



expansa, 429, 448. 



first of, 178. 



gigantea, 475. 



granulata, 449. 



Grayvillensis, 342. 



gregaria, 189. 



lenticularis, 201 ,* 203, 209. 



litorea, 223,* 228. 



Meekana, 303. 



sphaerulata, 333 * 342. 



tabulata, 333 * 342. 

 Pleurotomidse, 509. 

 Plicated rocks, effects of eros- 

 ion of, 652. 

 Plicating force, acting from the 

 ocean, 401, 826. 



amount of, 401. 



Plicating force, slow and long 



continued, 401. 

 Plication of clayey layers, 666.* 



of layers, caused by slides, 

 666. 

 Plications, causes of, 666, 785, 

 798. 



Appalachian, characters of, 

 395. 



map of axes of, in Pennsyl- 

 vania, 397.* 



of Archaean, 148,* 165. 

 Plicatula, 475. 



inflata, 476. 



placunea, 476. 

 Pliocene, 490,§ 495. 



plants of, in Europe, 515. 



See, further, Tkrtiart. 

 Pliopithecus, 519.§ 

 Pliosaurus, 443, 444, 449, 476. 

 Plombieres, zeolites formed at, 



777. 

 Plum, 514. 

 Plumbago, 59. § 

 Plumbaginous schist, 68.§ 

 Plutonia Sedgwickii, 180. 

 Plymouth group, 282. 

 Poacites, 499. 

 Pocillipora, 620, § 621. 

 Podophthalmus, 475. 

 Podopilumnus, 475. 

 Podozamites lanceolatus, 407,* 



409. 

 Poebrotherium Wilsoni, 511. 

 Poecilitic (Poikili tic) group, 424. 

 Poecilopleuron , 450. 

 Point Levi, rocks of, 184. 

 Poland, Cretaceous in, 470. 



Quaternary in, 532. 



Triassic in, 424. 

 Polar current, 41, 669. 



zone, 609. 

 Pole of land-hemisphere, 10. 

 Polishing of rocks. See 



Scratches. 

 Pollicipes, 475. 

 Polycotylus latipinnis, 467. 

 Polycystines, 132, 496,§ 615. 



of Barbadoes, etc., 615. 



in Richmond Tertiary, 496. 

 Polygenetic chaiu, 796. 

 Polynesian chain of islands, 



32* 

 Polyps, 127,§ 180, 189, 341, 472, 

 598. 



first of true, 199. 



number of Silurian, 249. 



range of, in time, 385, 386* 

 Polysporia, 349. 

 Polypterus, 282. 

 Polyptychodon, 474, 476. 

 Polythalamia. See Rhizopods 

 Polyzoans, 127. § 

 Ponent series, 375. 

 Poplar, 459, 497, 514. 

 Populites, 459. 



fagifolia, 459. 

 Populus, 497. 



Arctica, 498. 



decipiens, 498. 



lancifolia, 498. 



Zaddachi, 49S. 

 Porambonites, 171. § 

 Porcelain jasper, 73. § 

 Porcelanyte 73. § 

 Porcellia, 284,§ 429. 

 Porcellio, 120* 

 Porcupine, 508. 

 Porites, 610, 620,§ 621. 



