INDEX. 



5G3 



Page. 



Permian 112,150 



Perna formosa 361 



Pcronrea 1 scitola 462 



Pholadomya fibrosa 386 



huniilis 461 



Phonolito 483, 503 



character described 492 



gelatinization of 503 



hornblende in 493 



nephelite in 492, 503 



nosite in 493, 504 



sanidin in 492 



Piestocheilus eulbertsoni 423 



Pinna fibrosa 386 



riacenticeras placenta 464 



Placer deposits 237, 242, 289 



Placers of the foothills 289 



Plagioelase in mica-slate '... 4S0 



hornblende-gneiss 479 



rhyolite 487, 507 



trachyte 490 



Plains, the great 22 



rainfall of 309 



Tertiary of 24 



Planorbis veturnus 461 



Plants collected 531 



Plateau, Carboniferous 115, 117 



Pleuromya nebrascensis 461 



ne wtoni 367 



subcompressa 368 



Pleurotomaria contorta 422 



Polypetalas 531 



Positions and altitudes 551 



Potsdam and Carboniferous, separation of 109 



conglomerate a source of placer gold 299 



granite pebbles in 79 



distribution of 83 



formation, character of 84, 86 



fossils of the 107 



gold from the 84, 103 



history, summary of 221 



metamorphism of 83, 85, 88, 103, 193, 200 



of New York 86 



the Black Hills, detailed description of. ... 98 



Rocky Mountains, quartzites of 90 



"Wind River Mountains 86 



Wisconsin 86 



on Anrphibious Creek 100 



Battle Creek 101 



Burntwood Creek 101 



Castle Creek 98,202 



French Creek 101 



Red Canon Creek 100 



Slate Creek - 99 



Spring Creek 102 



quartzites of 88 



resting on uneven surface ... 102 



sandstone, manner of formation 104 



metamorphism of 280, 285 



topography of 82 



the only representative of the Silurian uncon- 

 formable on the Archaean 81 



Powell, Maj. J. W., cited 28 



Precipitation : See Rain-fall. 



Page, 



Prionocyelus wyomingensis 440 



Prospecting at Mammoth ledge 242 



in the Bear lodge district 286, 287 



Black Hills 17,19 



foothills 291 



French Creek district ... 230 



Spring Creek district 240 



near Camp Terry 281 



on Bear Butte Creek 272, 282 



Box Elder Creek -■ 276 



Castle Creek 264 



Deadwood Creek 282 



Rapid Creek 267,271,291 



Red Caiion Creek 236 



Spearfish Creek 278 



"Whitewood Creek 282 



Protocardia shumardi 461 



Prout, Dr. H. A 8 



Psammobia 1 prematura 374 



Pseudomonotis (Eumicrotis) curta 354 



orbiculata 356 



Pseudoptera fibrosa 386 



sublevis 387 



Pteria linguiformis 384 



(Oxytoma) mucronata 357 



munsteri 357 



nebrascana 385 



(Pseudopteiia) fibrosa 386 



sublaevis 386,387 



Pty choceras 455 



crassuni 459 



meekanum 457 



mortoni 458 



Pumice-stone 485 



Purple limestone, topography of 132 



Pyrite in quartzite 473 



Pyrites 61 



Pyrrhotite in hornblende-gneiss 479 



Quartz, ferruginous 229 



in rhyolite - 486 



ledges 58,256 



of granite 70 



twinned crystals of 500 



veins 53, 59 



Quartz-trachyte 483 



Quaternary deposits 44 



gravels 298 



Quartzite 471 



cavities in quartz of 473 



cement in 472 



crystalline 473, 475 



cyanite in 472 



garnet in 472, 474 



granular 471 



hornblende in 472 



magnetite in 472 



mica in 471 



microlites in 473, 475 



of the schists 256 



orthoclase in 472, 473 



pyrite in 473 



rounded grains in 472 



secondary minerals in 472 



schistose 471 



