1070 



INDEX. 



Oahu, 150, 163, 179, 271*, 282 ; map 



of, 292 

 Obi-Irtish Eiver, 30 

 OboleUa, 425§, 481, 486, 496 ; crassa, 



471* ; plicata, 520 ; polita, 478* 

 Obolus, 72, 73 (composition of 



shell), 425§, 482, 521 ; Apollinis, 



427* ; Davidsoni, 567 ; Labradori- 



cus, 480 

 Obsidian, 64, S4§ 



— Cliff, 264*, 276, 337* 

 Occident, 21, 22 



Ocean, abyssal depths of, 229 

 amount of salts in, 120, 121 ; sili 

 cates ma'de at the bottom, 136 

 the great mineral spring, 120, 

 820 



— as a mechanical agent, 209 ; earth- 

 quake waves, 213 ; abyssal work, 

 229 



Oceanic currents, 42, 43, 46* 



— era, 440 ; islands, 20, 22, 23 ; life 

 not easily exterminated, 142 



Oceans, arrangement of, 17; depth, 



18, 19§, 380 

 Ocoee group, 468 

 Octopods, 424 



Oculina arbuscula, analysis of, 72 

 Ocydromus AustraUs, 1019 

 Odontaspis, 863 

 Odontidium, 163, 164*, 165 ; pinmi- 



latum, 894* 

 Odontocephalus, 591 

 Odontocetus, 927 

 Odontopolys compsorhytis, 916 

 Odontopteris, 637, 671, 685, 693, 699 ; 



obtusiloba, 704 ; Schlotheimi, 670*, 



689 ; sphenopteroides, 689 

 Odontopteryx, 923§ 

 CEningen, fossils at, 921, 922, 926 

 Oesel zones, 568 

 Ogden, Utah, 360*, 361 ; Canon, 



581 ; quartzyte, 580, 581 

 Ogygia, 482, 520, 521 ; Buchii, 520 

 Ohio, mean height of, 23 ; mineral 



oil and gas, 522, 523, 554, 607, 608, 



609 

 Ohio Eiver, filled by drift, 965 

 Ohio shales, 603, 606, 615 

 Ohiocrinus, 516 

 Oil. See Mineral oil 

 Oil-creek group, 638 

 Oil-sand, 607 

 Okhotsk Sea, 927 

 Oklahoma. 836 ; mean height of, 



23 

 Oland, 521 

 Olcostephanus Astierianus, 865 ; 



Speetonensis, 865; Traskii, 837 

 Oldhamia, 482 ; antiqua, 481* ; 



radiata, 481* 

 Olean conglomerate, 647 

 defiant gas, 523 

 Oleic acid, 124 

 OleneUus, 467, 473*, 479, 481, 482 



asaphoides, 473 ; Callavei, 481 



GOberti, 473, 474* ; Kjerulfl, 482 



Thompsoni, 473* ; Vermontanus, 



473* 

 Olenellus zone, 464, 482 

 Olenoides, 482 ; Fordi, 473* 

 Olenopsis, 482 



Olenus, 481, 482, 483; mlcrurus, 



481* 

 Olenus schists, 482 

 Oligobunis, 918 

 Oligocarpia, 699, 756 ; Gutbieri, 



699 ; robustior, 749* 

 Oligocene, 880§, 886, 918, 920, 921, 



926 

 Oligoclase, 64*§ ; gneiss and granite, 



83 

 Oligoporus nobilis, 641*, 646 

 Oliva, 922; Mississippiensis, 916 

 Olivella, 916 



Olivine. See Chrysolite 

 Omnivores, 930 

 Omosaurus armatus, 787 

 Omphacyte, 88§ 



Omphyma, 567 ; turbinata, 564*, 567 

 Onchidium, 424§ 

 Onchus, 546, 565, 626 ; Clintoni, 546, 



550 ; Deweyi, 550 ; tenuistriatus, 



566* 

 Oncoceras, 551, 561 ; gibbosum, 



549 ; ovoides, 558, 562 

 Oneida conglomerate, 538 

 Oneonta sandstone, 608, 606, 612, 



618, 621 

 Oniscia harpuia, 916 

 Oniscus, 509, 783 

 Onoclea sensibilis, 840, 922 

 Onondaga beds, sections of, 552, 



553* 



— Lake, 553 



— limestone, 576, 581 



— period, 408, 410, 535, 552-558, 570, 

 572 



— salt group, 552 

 Ontarian, 446 



Ontario, salt group in, 552 

 Ontario (Lake), 200, 201*, 494, 533, 



946, 947 (depth) 

 Onychodus, 417 ; sigmoides, 589* 

 Onyx, 133 



Oolitic, 82 ; limestones, 79 

 Oolyte, 79§, 96§ 



— ,Bath, 775, 777, 790; Corallian, 

 790; Great, 775, 777, 779, 790; 

 O.xford, 775, 790 



Oolytic epoch, 738, 775 

 Opal, 62§, 64§, 135 

 Operculates, 54 

 Ophiacodon grandis, 688 

 Ophiderpeton, 706; Brownriggii, 704 

 Ophileta, 495, 499*, 515, 520 ; com- 



pacta, 500, 520 ; complanata, 499* ; 



levata, 499* ; Owenana, 514 ; pri- 



mordialis, 478* ; uniangulata, 499* 

 Ophiolyte, 79, 89§ 

 Ophiurans, 55 

 Ophiuroids, 429§, 505*, 646 

 Ophyte, 86§ 



Opossum, 415, 902, 910, 924, 926 

 Oppelia, 794 

 Oquirrh Mts., 840, 469 

 Oracanthus Milleri, 702 

 Oracodon conulus, 858* 

 Orang-outang, 54 

 Orange, N,J,, columnar basalt, 



262* 



— Bay, 858 



— sand group, 891, 965 

 Orbicula, 482 



Orbicular dioryte, 87§, 97* 

 Orbiculoidea, 514, 612 ; Lodensis, 



612*, 620 ; niinuta, 592, 602 ; ru- 



gata, 567 ; tenuUamellata, 562 ; 



Vanu.xemi, 557 

 Orbitoides, 433§, 896 ; Mantelll, 896, 



898* 

 Orbitoides limestone, 896 

 Orbitolites, 433§ 

 OrbituUna conoidea, 865 ; discoidea, 



865 

 Orbitulites Texanus, 834*, 836 

 Orbulina universa, 432* 

 Orca, 144 

 Orchestia, 420* 

 Orchids, 435 

 Ordovician, 489 

 Ore, ores, 327, 345, 810 ; origin of, 



342, 343 

 Oregon, 28, 25; glaciers of, 240; 



igneous action in, 265, 266, 280 ; 



volcanoes of, 296 ; Cretaceous 



in, 818, 830; Tertiary, 882, 885, 



892 ; John Day beds of, 911 ; 



sandstone veins, 344 

 Oreodon, 907, 918 ; gracilis, 910* 

 Oreodon beds, 886, 894, 910, 918 

 Oreodoxites plicatus, 839 

 Oretl series, 770 

 Organic acids, 665 



— contributions to rock-making. 

 See Kocks, organic constituents 

 of 



— nature, essential elements of, 9, 

 413 



— remains, 71§ 

 Orient, 21, 22 

 Orinoco River, 80, 466 

 Oriskany period, 577 



— sandstone, 577, 578 

 Orizaba (Mt.), height of, 937 

 Ormoceras, 501 ; crepriseptum, 516 ; 



tenuifilum, 514 

 Ormoxylon Erianum, 622 

 Ornithomimus, 847, 856 ; velox, 



847* 

 Ornithopoda, 761, 764, 786, 845, 863 

 Ornithorh3'nchus, 415, 795 

 Ornithostoma, 863 

 Orodus, 644, 692, 702 ; mammUlaris, 



644*, 647 

 Orogenic work, 845, 876§, 391 



— movements. Tertiary, of Long 

 Island and Martha's Vineyard, 

 1021*. See further. Mountain- 

 making 



Orohippus, 905, 912, 918*, 918;, 

 agilis, 905* 



Oromer3'x, 918 



Orthacanthus, 687 ; arcuatus, 692 



Orthaulax Gabbi, 899*, 917 ; pugnax, 

 916 



Orthaulax bed, 891 



Orthids, 719 (time range) ; Upper 

 Silurian, 574 



Orthis, 810, 425§, 426§, 481, 482,516, 

 517, 521, 550, 561, 562, 568, 579, 

 622, 642, 705 (last in Permian), 

 707 ; acuminata, 503 ; arcuata, 625 ; 

 biforata, 507*, 514, 520, 550 ; BU- 

 llngsi, 475*; biloba, 548*, 551; 

 boreahs, 503 ; Bouchardi, 520 ; 



