INDEX 



Pelecypods continued 



Permian, 676 



Silurian, 551 



Tertiary, 794, 825 



Triassic, 699 



Waverly, 611 



Pelde, eruption cloud of, 381 

 Peleosauropus primaevus, 619 

 Pelycosaurus, 672 

 Penck, A., 894 

 Peneplain, 125 

 Penhallow, D. P., 786 

 Pennsylyanian period, 596, 620 



amphibians of, 652 



anthracite coal-field of, 624 



duration of, 640 



invertebrates, marine, 657 



iron ore, 638 



land animals of, 652 



life, fresh-water, 655 



marine, 656 



plants, 643 



system of the west, 627 



system, thickness of, 630 

 Penrose, R. A. F., 71, 797, 807 

 Pensauken formation, 901 

 Pentacrinus briareus, 714 

 Pentamerus oblongus, 550 

 Pentremites, 614 



robustus, 613 



Peorian interglacial interval, 874 

 Perched bowlders, 272 

 Peridotite, 30, 60, 86 

 Perisphinctes tiziani, 712 

 Perissodactyls, 789, 802 

 Perlite, 61, 86 

 Permanent stream, 117 

 Permian amphibians, 672 



brachiopods, 676 



climate of, 669 



conglomerates of Europe, 663 



faunas, 672, 674 



of Himalayan region, 696 



of India, 696 



of Mediterranean region, 696 



of Siberian region, 696 



floras, 669 



fresh-water life, 674 



glacial formations, 666 



gypsum, 661 



igneous activity, 665 



life of, 668, 669 



of Europe, 662 



period, 596, 660 



problems of, 677 



Permian continued 



salt beds, 665 



thickness of, 662 

 Pernopecten cooperensis, 608 

 Petrifaction, 44, 203 

 Petrified tree-trunks, 814 

 Petroleum, 79 

 Petrology, 1 



Phacoides foremani, 825 

 Phacops logani, 576 



rana, 585 



Phanerites, 19, 59, 60 

 Phenacodus primaevus, 788 

 Phillipsia major, 658 

 Phonolite, 86 

 Phosphates, Devonian, 572 



in Tennessee, 517, 572 



Miocene, 807 

 Phosphatic nodules, 326 

 Phragmoceras nestor, 551 

 Phyllite, 86 



Phylloceras knoxvillensis, 741 

 Phyllograptus (?) cambrensis, 500 



ilicifolius, 531 



typus, 531 



Phyllotheca indica, 671 

 Physiographic geology, 1 

 Piedmont alluvial plain, 181 



alluviation, 833 



glacier, 232, 235 

 " Pilot Rock, "850 

 Pinnipeds, Eocene, 793 

 Piracy, 162 



in the Appalachians, 176 

 Pirsson, L. V., 59 

 Pitchstone, 61, 86 

 Pithecanthropus erectus, 844 

 Pittsburg coal bed, 625, 637 

 Plagioclase, 79 

 Planetary motions and planetesimal 



hypothesis, 424 

 Planetesmial hypothesis, 416, 420 



stages of growth under, 432 

 Planetesimal nebulae, 422 

 Plants, agents of deposition from 

 solution, 205 



Cambrian, 495 



Carboniferous, 643 



Comanchean, 737 



Cretaceous, 759 



Devonian, 593 



Jurassic, 719 



Mississippian, 619 



Ordovician, 534 



Pennsylvanian, 643 



