INDEX. 



Note. — An asterisk (*) after the number of a page indicates that there is a reference on the page 

 to a figure of the species or object mentioned ; and a section-mark (§) implies that the page contains 

 a definition, explanation, or characteristic of the word or object mentioned. 



Abieh, analysis of trachyte, 



77. 

 Abies, 450, 497. 

 Abyssal zone, 611. 

 Abyssinia, plateau of, 27. 

 Acacia, 514, 515. 

 Acadian epoch, 163, 166. 



Triassic, 404. 

 Acalephs, 117,*127,§ 129,§ 341. 



range of, in time, 386. 

 Acanthospongia, 207. 

 Acanthotelson Eveni, 342. 



Stimpsoni. 334,* 342. 

 Acanthoteuthis, 441. 



antiquus, 44').* 

 Accipenser, 264. 

 Accumulation of rock-material, 



615. 

 Acephals, 124, 125.§ 



range of, in time, 397.* 

 Acer, 459, 497. 



obtusilobum, 459. 

 Aceratherium occidentale, 507. 

 Acetabulifers. 439. 

 Acidaspis, 240, 249. 253. 



Barrandei, 247. 



range of, in time, 387.* 

 Acidic series of igneous rocks, 



79,§ 736. 

 Acid-spring, 234. 

 Aclis robusta, 342. 

 Acrodonts,338.§ 

 Acrodus, 428, 475. 



minimus, 262,* 429. 



nobilis, 262,* 449. 

 Acrolepis, 372. 



Sedgwickii, 372. 

 Acrostichites oblongus, 409. 

 Acrogens, 133. § 



Age of, 139. 



range of, in time, 140.* 

 Acrotreta, 173,§ 190. 



gemma, 250. 



subconica, 250. 

 Actaeonella, 475. 

 Actaeonina, 475. 

 Actinia, 117.* 

 Actinoid Polyps, 130.§ 

 Actinolite, 54.§* 

 Actinolvte, 70. § 

 Actinocrinus, 303, 341. 



(Batocrinus) longirostris, 

 118,* 129,§ 298* 303. 



proboscidians, 298,* 303. 



pulcher, 247. 



tenuiradiatus, 191. 

 Actmocyclus Ehrenbergii. 496. 



Actinoptychus undulatus, 496.* 



senarius, 134,* 496.* 

 Activity in matter, beginning 



of, 766. 

 Adacna vitrea, 610. 

 Aderholt, analyses of Lycopod 



ash, 365, 366. 

 Adiantites, 348. 

 Adipocere, 617- 



Silurian, 612. 

 Adirondack iron-mines, 151. 



mountains, 390, 750. 

 Adjutant, 516. 

 Admete viridula, 551. 

 ^Echmodus, 442.* 



angulifer, 449. 



Leaohii, 449. 

 JSglea, 350. 

 jEglina binodosa, 192. 

 iEpyornis, 580. 

 iEthophyllum speciosum, 426. 



stipulare, 426. 

 Africa, Cretaceous in, 470. 



mean height of, 14. 



plateaus of, 22. 



system in reliefs of, 27.* 



Tertiary in, 512. 

 Agalmatolite, 58. § 

 Agaricia, 620. 

 Agassiz, A., Echini, 595. 

 Agassiz, L , criteria of rank 

 among animals, 592. 



Drift, 537. 



glaciers, 680. 



Man's position in classifica- 

 tion, 578. 



names of Ages, 138. 



tails of fishes, 412. 

 Agassizocrinus, 341. 

 Agate, 53. § 

 Age of Acrogens, 139. 



of Fishes, 140, 254. 



of Invertebrates, 162. 



of Mammals, 589. 



of Man, 141, 527. 



of Reptiles, 403. 

 Agelacrinites Billingsii, 203. 



Buchianus, 207. 

 Ages, names of, 140. 



reality of, 137. 



subdivision into, 138. § 

 Aglaspis, 168, 178. 

 Agnostus. 168, 178, 180, 188, 

 190, 253. 



Acadicus, 175,* 176. 



integer, 180. 



lobatus, 202,* 204. 



Agnostus nobilis, 178. 



pisiformis, 208. 



princeps, 180. 



rex, 180.* 

 Agraulos, 168, 178, 189. 



Oweni, 178. 

 Agriochcerus, 511. 



antiquus, 611. 



major, 511. 

 Aiguille, 645. § 

 Air, oxygen in, 49. 

 Air-breathers, first of, 273, 301. 

 Alabama, Carboniferous in, 291, 

 311. 



Cincinnati in, 197. 



Clinton in, 219. 



Cretaceous in, 455, 456. 



glaciers in, 537. 



Millstone-grit in, 311, 320. 



Subcarboniferous in, 294, 305. 



Tertiary in, 491, 494. 



Triassic in, 423. 



in the Cretaceous, 479. 



period, 490, 494, 509, 523. 

 Alabaster, 56. § 

 Alaska, Triassic in, 407. 

 Albertite, 296, 315, 316. 

 Albian group, 470. 

 Albite, 54.§ 

 Albite-felsyte, 71. § 

 Alca impennis, 580. 

 Alcjonium, 130 § 

 Alcyonoid Polyps, 130. § 

 Alder, 515. 

 Alethopteris, 330, 348, 370. 



discrepans, 271. 



lonchitica, 326,* 330, 331. 



marginata, 331. 



Owenii. 297. 



Serlii, 330. 

 Aletornis gracilis, 510. 



nobilis, 510. 

 Aleutian Islands, 35. 

 Algas, 133, 134,5 139* 140, 611, 

 665. 



Carboniferous, 296, 331. 



Devonian, 257, 277. 



Silurian, 169, 186, 223, 242. 



the earliest plants, 140.* 

 in hot waters, 611. 

 Alleghanv Mts., in Paleozoic, 

 390, "395, 750. 

 age of, 754. 

 Carboniferous in, 291. 

 Alligator, 510. 



Allorisma subcuneata, 332,* 

 342. 



