INDEX. 



AARDV.ARK, 569. 



A an) wolf. 613. 



Abdominalia (Cirn'pedia), 233 ; (Fishes), 



40P. 



Abranchiata (Vertebrata), 383. 

 Abyla, 105. 

 Acalepkce, 110. 

 Acanthocephala, 183, 190 ; characters of, 



1<J2, 193. 



Acanthodidce, 415. 

 A canthomet ra, 67. 

 Acanthometrina, 67. 

 Acanthophis, 458. 

 Acanthopteri, 411. 

 Acanthopterygii, 400, 406. 

 Acanthospongia, 75. 

 Acarida, 259. 

 Ocarina, 258; characters and families of, 



-'59. 



Accipitrince, 530. 

 Acephala (Mollusca), 320. 

 , 645. 



.Acetabula, 345. 



Achtheres, 227. 



-dc/cwZa, 341. 



Aciculidce, 341. 



Acineta, 76, 82. 



Jcipenser, 428. 



Acmcea, 340. 



Acorn-shells, 229, 231. 



Acrodus, 422, 641. 



Acrotreta, 317. 



Acrydium, 280. 



Acteonia, 341. 



Actinia, 126, 128. 



Actinidce, 128, 1'29 ; development of, 129. 



Actinomeres, 143. 



Actinophrys, 58, 60, 67. 



Actinosoma, 127. 



Actinozoa, 88 ; characters of, 125 ; divi- 



sions of, 127 ; distribution of, 147. 

 Aculeus, 288. 

 Adelarthrosomata, 258 ; characters and 



families of, 261. 

 jEffinidce, 113, 1^0. 

 jfiginopsis, 113. 

 jEolidae, 341. 

 jEolis, 341. 

 jEpiornis, 535. 

 .dj/anncte, 465. 

 ^4 gapornis, 520. 

 A ffuthistega, 63. 

 Avelacrinites, 175. 



Agouti, 610. 



A Hums, 609. 



Air-bladder of Fishes, 398. 



Air-receptacles of Birds, 493, 494. 



u4 Zcedo, 528. 



,4/.ca, 503. 



A Ices, 594. 



-1 Za'dce, 503. 



ALcyonaria, 127 ; characters and divisions 

 of, 137 ; distribution of, in time, 151. 



AlcyonidcK, 137. 



Alcyonium, 138. 



Allantoidea, 384. 



Allantois, 383. 



Alligator, 468, 470. 



Alpaca, 591, 592. 



Alveolus (Belemnite), 353. 



Amber, insects preserved in, 292. 



Amblyrhynchus, 467. 



Amblystoma, 436. 



Ambulacral system (Echinodermata), 15. 1 ), 

 156 ; of Echinus, 160 ; of Star-fishes, 

 165 ; of Ophiuroidea, 169 ; of Crinoidea, 

 170 ; of Holothuroidea, 178, 179. 



Ameiva, 464. 



A metabolic Insects, 274, 277. 



Amia, 416. 



Amiadce, 415. 



A mmodytes, 410. 



Ammonites, 356, 357, 358. 



Ammomtidce, 356, 357 ; characters of, 357 ; 

 distribution of, in time, 361. 



Amnion, 383. 



Amniota, 383, 384. 



Amaba, 7, 53; structure of, 54 ; pseudo- 

 podia of, 56 ; reproduction of, 56. 



Amabea, 5.3, 58. 



Amcebina, 58. 



Amphibia, 383, 384, 424, 425; general 

 characters of, 431 ; development of, 

 ib. et seq. ; respiratory organs of, 432; 

 orders of 433 ; distribution of, in time, 

 443. 



Amphiccelia (Crocodilia), 469, 470. 



Amphidiscs, 72. 



Amphilestes, 639. 



Amphinomidce, 212. 



Amphioxus, 3^2, 380, 397, 400r~- -<-_^__ t 



Amphipneusta, 435. 



Amphipoda, 226, 242 ; characters of, 24G ; 

 heart of, 244. 



A mphisbcena, 461, 462. 



Amphispongia, 75. 



Amphitherium, 639, 640. 



Amphiuma, 435, 4^7. 



