INDEX. 



Acrogens (point-growers or apex- 

 growers), age of, 295. 

 African fauna explained, 404. 

 Agencies, geological, 9. 

 leveling and elevating, 131. 



Air, chemical action of, 14. 

 mechanical action of, 15. 



Albertite ; a form of asphalt, 313. 



Alkaline lakes, deposits in, 77. 



Alpine species, 403. 



Ammonite (horn of ammon stone), 

 330. 



Amphibians (living in both [air 

 and water] ), called also batra- 

 chians, 319-328. 

 age of, 297. 



Amphicoelias (amphi, both sides; 

 koilos, hollow ; double con- 

 cave), 347. 



Amygdaloid, 223. 



Anchisaurus, 344. 



Ancyloceras (curved horn), 353. 



Andesite, 214. 



Angustifolius (narrow leaf), 274. 



Anomodont (lawless tooth), 328. 



Anomcepus (unlike feet), 343. 



Anoplotherium (unarmed beast), 



Anticline and syncline defined, 



188. 



Apiocrinus (pear crinoid), 331. 

 Appalachian revolution, 322. 

 Aqueous agencies, 17. 

 Aquitanians, primeval, 411. 

 Archaean (relating to earliest 



times), 259. 

 rocks, area of, in the United 



States, 265. 

 rocks, character of, 264. 



LE CONTE, GEOL. 27 



Archasan system, 263. 

 times, life of, 265. 

 times, physical geography of, 

 265. 



Archaeozoic (primeval life), 259. 



Archegosaurus (primordial liz- 

 ard), 320. 



Archaeopteryx (primordial winged 

 creature), 337. 



Artesian wells, 70. 



Asteroid (star-like), 277. 



Asterolepis (star-scale), 291. 



Atlantosaur (great lizard) beds, 

 345. 



Atmosphere, chemical action of, 



14 

 mechanical action of, 15. 



Atmospheric agencies, 10. 



Baculite (stone-staff), 354. 

 Bad Lands, 248, 366. 

 Banks, Bahama, 50. 



in North Sea, 50. 



of Newfoundland, 50. 



submarine, 49. 

 Bars, how formed, 38. 



position of, 38. 



removal of, 40. 

 Basalt, 139, 215. 



columnar structure of, 220. 

 Base level of erosion, 28. 

 Bed-rock surface, 387. 

 Belemnite (stone dart), 332. 

 Birds, 337. 



Bitumen and petroleum, 313. 

 Blastids (bud-like), 279. 

 Borax lakes, 77. 

 Botanical regions, 119. 

 Bowlders, 387. 



of disintegration, 12. 



417 



