INDEX. 



Absence of certain animals in fossiliferous 

 deposits, how accounted for, 27-39. 



Acanthocladia, 196, 529. 



Acanthodes, 330. 



Acanthodidce, 322-330. 



Acanthopteri, 318. 



Acanthonpongia, 68. 



Acanthotelson, 177. 



Acanthoteuthis, 295. 



Acarida, 182. 



Acasta, 152. 



Acaste, 170. 



Acer, 502. 



Acerotherium, 425, 426. 



Achatina, 266. 



Acicula, 268. 



Aciculidce, 268. 



Acidaspidce, 171. 



Acidaspis, 171. 



Acipenser, 322, 333. 



-Acmoea, 259. 



Acorn-shells, 150. 



Acrodont Lizards, 362. 



ulerodws, 335, 337, 339, 340, 410. 



Acrogens, 473 ; age of, 476. 



Acrotepis, 530. 



Acrosalenia, 110. 



Acrostichites, 497, 533. 



u4cr<mra, 117. 



Acteonella, 261. 



.dcteonma, 261. 



.AcZtma, 86, 87. 



Actinocrinuii, 121, 126. 



Actinospongia, 537. 



J.cii?iozoa, 73; characters, 85; distribu- 

 tion in time, 86. 



Adductor muscles of Lamellibranchiata, 

 218. 



jEchmodus, 324. 



jEglina, 169. 



jEpiornis, 390, 394. 



jEquoridce, 74. 



Aganides, 288. 



Age of Acrogens, 476; of Gymnosperms, 

 476; of Angiosperms, 476. 



Agelacrinus, 129, 133. 



Agnostidce, 167 



Agnostus, 162, 163, 167, 168. 



.4ces, 435. 



Alcyonaria, 73; characters of, 101; dis- 

 tribution of, in time, 101. 



Alcyonium, 101. 



Alethopteris, 482, 486, 494. 



^ce, 473, 477. 



Alligator, 366, 367. 



s, 500. 



Alum-schists, of Sweden, 510. 



Amber, insects preserved in, 186. 



Amblypterus, 323, 534. 



Amblyrhynchus, 365. 



Ambonychia, 223, 224. 



Ambulacral ossicles of Star-fishes, 112, 113. 



Ainia, 323. 



Amiadas, 322, 323, 327. 



Ammonites, 289 ; sections of, 290. 



Ammonitidce, 279, 280, 281; characters 

 of, 286; shell of, 279, 286. 



Amcebea, 59. 



Amphibia, 305; characters of, 346; orders 

 of, 347 ; distribution of, in time, 347. 



Amphicoelia (Crocodilia), 36(>, 367. 



Ainphwyon, 450. 



Amphidetus, 109. 



Amphihelia, 96. 



Amphilestes, 405, 410. 



Amphion, 170. 



Amphipoda, 176. 



Amphisbcena, 361. 



Amphispongia, 69. 



Ainphistegma, 63. 



Amphitherium, 405, 410, 411. 



Amphitragulus, 434. 



Amphiura, 117. 



Amplexus, 526. 



Ampullaria, 245, 255. 



Ampyx, 167, 169. 



Anabacia, 537. 



Anacanthini, 317. 



Ananchytes, 109. 



Ananchytidce, 109. 



Anarthropoda, 136. 



Anatifa, 153, 155. 



Anatina, 238, 239. 



^4vimwZoe, 218, 238. 



Anchitherium, 428 



Ancyloceras, 291, 292. 



Ancylotherium, 414. 



Ancylus, 268. 



Andrias, 347, 348. 



Angelina, 161, 167, 169. 



Angiosperms, 473. 



Anguis, 361. 



Animal Kingdom, divisions of, 44-52. 



Anisopus, 533.' 



,4nnelMta, 136 : characters of, 136 ; distri- 

 bution of, in time, 137. 



^nnwZaria, 478, 482, 483, 494. 



Annuloida, 102. 



Annulosa, 29, 47 ; characters of, 136 ; dis- 

 tribution of, in time, 136. 



