Amphipoda, 268, 286; characters of, 287; heart of, 287. Amphisbona, 526. Amphisbænidæ, 526. Amphitherium, 627, 641. Amphiuma, 492, 495, 497. Amplexus, 166. Anacanthini, 467. Anallantoidea, 440. Analogy, 21. Anamniota, 440. Anarthropoda, 240. Anatidæ, 582. 584. Anatinida, 385, 386. Andrias, 497. Androphores, 124. Anelasma, 291. Angelina, 282. Angler, 465. Anguillula, 231, 232. Anguillulida, 232. Anguis, 526, 527. Ani, 596. Animals and Plants, differences between, Apoda (Cirripedia), 267, 276; (Amphi- bia), 493; (Fishes), 465, 467. Apodemata, 263. Aporosa (Corals), 155, 175. Appendicularia, 366, 369. Apsilus, 234. Aptenodytes, 579. Aptera, 324, 327. Apterygida, 572, 574. Apteryx, 556, 558, 567, 572, 573, 574, 575. Aquiferous system (see Water-vascular Arachnactis, 146, 148, 171. Arachnida, 259; characters of, 298; so- Araine, 596. Araneida, characters of, 308; webs of, Arcella, 63, 64. Arcellina, 64. Archæocidaris, 191, 212. Archaeopteryx, 553, 570, 571, 608, 609. Architarbus, 310. Argonauta, 352, 401; shell of, 408, 409; Armadillos, 616, 627, 644, 645, 647. Artemia, 280. Arthropoda, 240; characters and divisions Articulata, 258. Articulata (Brachiopoda), 375, 376. Artiodactyla, 663, 670. Arvicola, 715. Asaphus, 282. Ascuris, 230, 231, 232, 233. Ascidians, solitary, social, and compound, 368, 369. Ascidioida (see Tunicata). Ascoceras, 416. Asellus, 289. A sinus, 668. Asiphonida (Lamellibranchiata), 385, 386. Aspidisca, 88. Aspidorhynchus, 473. Astacus, 291. Asplanchna, 236. Barbadoes Earth, 75. Barbel, 466. Barbets, 598 Barnacles, 271, 272, 274. Barrier-reefs, 172, 173, 174. Bascanion, 521. Basiliscus, 529. Bathybius, 60. Bathycrinus, 202, 210. Batides, 478, 479. Batrachia, 498. Bats, 543, 617, 618, 620 et seq. Beaked Rays, 480. Bear, 698, 701, 702, 709. Bear-animalcules, 304. Bearded Vulture, 607. Bed-bug, 332. Bee-eaters, 603, 604. Bees, parthenogenesis of, 37; communi- ties of, 342. Belemnites, structure of, 412. Bellerophina, 398. Bellerophon, 398. Belodon, 537. Beluga, 473. Beroida, 170. Bighorn Sheep, 684. Bimana, general characters of, 736. Botaurus, 587. Bot-flies, 338. Bothriocephalus, 217, 22). Brachiopoda, 349, 350, 351, 354; general Ca ca, intestinal (of Birds), 562. Callograptus, 141. Callorhynchus, 477. Calveria, 190, 212. Calycophoridae, 120; polypites of, ib.; Calyptoblastic Hydroids, 114. Calyptræide, 394. Calyx (of Vorticella), 91; (of Crinoids), 199, 210. Camelida, 624, 676, 677, 678, 686. Camelopardalidæ, 677, 681. Camelopardalis, 681. Camelus, 677, 678. Campanularia, 119. Chevrotains, 677, 678. Chigoe, 336. Chilognatha, 313. Chilopoda, 313. Chimera, 477, 478. Chitonide, 394. Chorda dorsalis (see Notochord). Chromatophores, 401. Chrysalis, 325. Chrysaora, 134. Clepsine, 247. Cloaca, of Rotifera, 235; of Insecta, 321; Clotho, 521. Coccide, 330, 331. Coccoliths, 74. Coccosteus, 474, 475, 485. Coccothraustes, 601. Cockle, 386. Cockatoo, 596. Cockroach, 332, 333. Cocoon, 326. Cod, 467. 98; Chrysochloris, 723. Chrysopa, 334. Chub, 466. Chylaqueous canals (Medus), 127. Chylaqueous fluid, of Rotifera, 235; of Annelida, 244, 252. Chylific stomach of Insects, 321. Chyme-mass of Infusoria, 89. Cicada, 331, 332. Cicindelida, 345. Ciconia, 587. Cidaris, 185. Cilia, of Sponges, 79; of Infusoria, 89, 91; Ciliata (Infusoria), SS. Cinclides, 147. Cimolornis, 583. Cirrhi, of Annelides, 243, 252; of Cirri- Cirrhopoda (see Cirripedia). Cirripedia, 41, 267; general characters of, 271; development of, 272; shell of, Cirrostomi (see Pharyngobranchii). Cladocera, 268; characters of, 279. Clangula, 582 Classification, 23 29. Clavatella, 110. Cleodora, 399, 400. Codonella, 89. Colenterata, 86; characters of, thread-cells of, 100; divisions of, 101. Cœlogenys, 718. Coenenchyma, 154. Conccium, 355. Cœnosare, 103; of Oceanic Hydrozoa, 120; of Physalia, 123; of Velella, Conurus, 220. Coleoptera, 318, 327, 323; mouth of, 319; characters of, 344; sections of, 345. Collocalia, 604. Collosphæra, 76. Columbacei, 590, 593. Columbida, 593. Columella, of Corals, 152; of the shells of Gasteropoda, 392. Column, of Actinidæ, 146. Comatula, 202, 203. 209, 211. Conchicolites, 255. Conchifera, (sce Lamellibranchiata). Condor, 608. Condylura, 722. Comida, 394. Conirostres, 599. Conodonts, 485. Conosmilia, 166, 175. Contractile vesicle, of Protozoa, 55; of |