INDEX 



709 



Molluscoidea — (Continued) 



Devonian, 457. 



Ordovician, 431-432. 



Silurian, 446-447. 

 Monadnocks, in, 118. 

 Monoclines, 256. 

 Monograptus clintonensis, 428. 

 Monopteria longispina, 483. 

 Montana formation, 517, 571. 

 Monterey Formation, 581. 

 Moraines, ground, 161, 177. 



lateral, 154, 155, 156. 



medial, 154, 155, 156. 



recessional, 160, 175. 



submarginal or bank, 161. 



terminal, 159-160, 175. 

 Morrison formation, 515. 

 Mosasaurs, 555-556. 

 Moulins on glaciers, 149. 

 Mountain folding, 358-363. 



and crustal shortening, 359. 



causes of, 364-367. 



experiments in, 360-361. 



rate of, 362. 

 Mountains, age of, 369. 



classification of, 352. 



cycle of erosion of, 364. 



distribution of, 368. 

 Mount Etna, 322. 



Greylock, 73, 256. 



Hood, 318. 



Pelee, 306, 307. 



Shasta, 318, 321. 

 Mud cracks, 238. 

 Mud volcanoes, 323. 

 Muensteroceras oweni, 483. 

 Muir, John, 633. 



Muschelkalk beds, Germany, 511. 

 Muscovite mica, 690. 

 Myalina recurvirostris, 483. 

 Mylodon, 670. 



Nahant, a tied island, 223. 



Nansen, F., 169. 



Naraoia compacta, 412. 



Narrows, 86. 



Naticopsis altonensis, 482. 



Natural bridges, formed, by fall, 91. 



by perforation of neck of intrenched 

 meander, 112. 



by swallow holes, 71. 



from caves, 71. 



Natural levees, 123. 

 Nautilus, 530. 

 Neanderthal man, 675. 

 Nebular hypothesis, 385. 



contrasted with planetesimal, 387. 

 Neolithic man, 679-680. 

 Neuroptera, 532. 

 Neve, 142. 



New England peneplain, 114. 

 Niagara Falls, 89, 441. 



recession of, 658-659. 



slight erosion at brink, 85. 

 Niagaran formation, 441. 

 Niagaran limestone, 440. 

 Nile valley, flood plain of, 12 1. 

 Niobrara formation, 524. 

 Nipponites mirabilis, 530. 

 Nivation, 146. 

 Nodular flint, 524. 

 Norne, Alaska, gold of, 374. 

 Normal fault, 261-263. 

 Norton, W. H., 175. 

 Nostoceras stantoni, 530. 

 Nucleocrinus verneuili, 457. 

 Nummulites, 577, 626. 

 Nunataks, 170. 



Oases of Kerid, 64. 



Obelisk, City of New York, 28. 



Obolella atlantica, 414. 



Obsidian, 332. 



Ocean, age of, 198. 



depth of, 194, 195. 



extent of, 194. 



general character of, 194-202. 



temperature of, 196-197. 

 Ocean basins, permanence of, 368. 

 Ocean currents, 202. 

 Ocean floor, topography of, 194. 

 Ocean water, composition of, 195 

 196. 



movement of, 198-202. 

 Odontaspis cuspidata, 625. 

 Odontaspis elegans, 625. 

 Oil and gas, in Devonian, 455. 



in Ordovician, 425. 



in Pennsylvanian, 475. 



origin of, 425-426. 

 Old age of valleys, in. 

 Oldhamia antiqua, 409. 

 Old Red Sandstone, 455. 

 Olenellus, 402. 



