970 



INDEX 



Plants continued 

 Permian, 069 

 Pleistocene, 914-917 

 Silurian, 554 



Tertiary, 786, 818, 840 



Triassic, 691 



Platacarpus coryphaeus, 766 

 Plateau- forming movements, 355 

 Plataphemera antiqua, 595 

 Plataceras dumosum, 581 



gibbosum, 576 



primsevum, 498 

 Platyostoma broadheadi, 608 



niagarensis, 551 

 Platystrophia lynx, 528 

 Plectambonites sericeus, 528 

 Plesiosaurs, Cretaceous, 765 



Jurassic, 716 



Triassic, 694 



Plesiosaurus dolichodeirus, 718 

 Pleurocystis filitextus, 530 

 Pleurotoma potomacensis, 796 



tysoni, 796 



Pleurotomaria nodulostriata, 614 

 Pleistocene changes of level, 911 



deposits, glacial, see drift, 

 marine, 910 

 non-marine, 899 



life of Africa, 922 



life of Eurasia, 920 



life of North America, 914 

 of South America, 922 



period, 772, 846-930 



life of, 914 

 Pliohippus, 821 

 Pliocene formations of Alaska, 845 



of Europe, 840 



of the Pacific coast, 835 

 Pliocene period, 772, 828, 847 



climate of, 845 



crustal movements of, 835 



fauna of, 841 



flora of, 890 



marine beds of, 835 



volcanic activity of, 839 

 Plugs, 367 

 Plumbago, 79 

 Plutonic rock, 16 

 Plutonic rocks, 86, 367 

 Pocono formation, 597 

 Podocarpus, 761 

 Poison Canyon formation, 777 

 Polygyra clausa, 889 



monodon, 889 



multilineata, 889 



Polynices duplicatus, 826 

 Polypora lilaea, 576 

 Polyps, Gene vie ve fauna, 615 

 Ponded stream, 177 

 Popanoceras walcotti, 675 

 Porphyry, 19, 23, Mi 

 Portage beds, 559 



fauna, 587 



flora, 594 



Post-glacial life, 935 

 Potassium in igneous rocks, 23 



salts, 665 



Poterioceras apertum, 525 

 Pot-holes, 157 

 Potomac series, 728, 731 

 Potsdam series, 476 

 Pottsville series, 620, 626 



coal in, 620 



floras of, 644 



oil in, 620 



Pre-Cambrian formations, 471 

 Precession of equinoxes and climate, 



895 

 Precipitation from sea-water, 32 I 



from solution, 102 

 Prehistoric man, 923 

 Present period, 931 

 Prestwichia danse, 655 

 Primates, Eocene, 793 



Miocene, 823 

 Primitive rocks, 441 



volcanic eon, 431 

 Prionotropis woolgari, 770 

 Proboscidians, Miocene, 819 



Pleistocene, 919 



Pliocene, 843 

 Prodromites, gorbyi, 608 

 Productella pyxidata, 608 



spinulicosta, 581 

 Productids, 585 

 Productus, 581, 607, 612, 615 



arcuatus, 608 



burlingtonensis, 610 



costatus, 658 



fasciculatus, 614 



marginicinctus, 614 



nebrascensis, 658 



symmetricus, 658 

 PrSetus ellipticus, 60S 



parviuseulus, ."">_' I 

 Progonoblattina columbiana, ' 

 Prognostic geolo<;v, IM'J 

 Prosser, C. ., ">f7. 621. mil. , 

 Proterozoic, climate <>f, 171 



duration of, 467 



