INDEX. 



503 



Pagp. 



Pormion 112, 100 



Pomn formosa 3G1 



Purona;a I scit iila 402 



Pholadomya fibrosa 386 



huiailis 461 



Phonolild 483, 503 



character ilescribod 492 



gclatinization of 503 



homblcmlo in 493 



iippbiUto in 492, 003 



iiosito in 493, 504 



sanidin in 492 



Picstoclii'ilus culbortsoui 423 



I'inna fibrosa 380 



riacenticcias placenta 404 



I'lacer deposits 237, 242, 280 



Placers of the foothills 289 



Plagioclase in luica-slato 480 



hornblende-gneiss 479 



rhyoUto 487,507 



trachyte 490 



Plains, the great 22 



rainfall of 309 



Tertiary of 24 



Planorbis veturnus 401 



Plants collected 531 



riateaii, Carboniferous 115, 117 



Plcuniiuy:! nebrasccnsis 4GI 



no wtoni 367 



subcomprcssa . 368 



Pleurotoniaria contorta 422 



Polypotala; .. 531 



Positions and altitudes 551 



Potsdam and Caroonifirous, separation of 109 



conglomerate a source of placer gold 299 



granite pebbles in 79 



distribution of 83 



formation, character of 84, 80 



fossils of tho 107 



gold from the . . e4, 103 



history, summary of 221 



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



of New York 80 



the Black Ilills, detailed description of ... 98 



Rocky Mountains, quartzites of 90 



"Wind Kivcr Mountains 80 



Wisconsin 86 



on Amphibious Creek 100 



Battle Creek 101 



Bumtwood Creek 101 



CastlcCreek 98,202 



French Creek 101 



Eed Canon Creek 100 



Slate Creek 99 



SpringCrcck 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 tho Silurian uncon- 



foi-mable on the Arcbsau 81 



PoweU, Maj. J. "W"., cited 28 



Precipitation : See Kain-fall. 



Page. 



I'riouocyrlus wvoniingcuBis 440 



Pro.spi'cf iug at Mauimot h ledge 242 



iu 1 be Bt'ur lodge district 280,287 



Black Uills 17,19 



foothills 291 



Kreneli Creek district 230 



Spring Creek district 240 



near Camp Ten-y . . 281 



on Hear Butte Creek 272, 282 



Box Elder Creek 270 



Castlt! Creek 204 



Dead wood Creek 282 



Eapid Creek 207,271,291 



Kcd Canon Creek 230 



SpearCsh Creek 278 



Whitewood Creek 282 



Protoeardia shumardi 401 



Prout, Dr. n. A 8 



Psammobia ! prematura 374 



Pscudomonotis (Eumicrotis) curta 354 



orbiculata 350 



Pscudoptera fibrosa 380 



sublevis 387 



Pteria linguiformis 384 



(Oxytoina) mucronata 357 



munateri 357 



nobrascana 385 



(Pseudopteria) fibrosa 386 



sublaevis 386, 387 



Ptychoceras 455 



erassum 459 



meckanum 457 



mortoni 458 



Pumice-stone 485 



Purple limestone, topography of 132 



Pyrite in (luartzito 473 



Pyrites 61 



I'yrrhotito in hornblende-gneiss 479 



Quartz, firruginous 229 



in rhy olite 486 



ledges 58, 256 



of granite 70 



twinned crystals of 500 



veins 53, 59 



Quartz-tiachyte 483 



Qnatemaiy deposits 44 



gravels 298 



Qnartzite 471 



cavities in qnartz of 473 



cement in 472 



crystalline 473, 475 



cyanito in 472 



garnet in 472, 474 



granular 471 



hornblende in 472 



magnetite in 472 



mica in 471 



microlites in 473, 475 



of the schists 250 



orthoclase in 472, 473 



pyrite in 473 



rounded grains in 472 



secondary minerals in 472 



schistose 471 



