8 3 6 



INDEX. 



Nectocalyces, structure of, 128 ; in Caly- 

 cophoridce, 132 ; in Medusidce, 128 ; dis- 

 tinguished from the umbrella of the 

 Lucernarida, 137. 



Neetosac, 128. 



Needham, moving filaments of, 422. 



Nematelmia, 229 ; characters of, 242. 



Xernatocysts, 107. 



Nematoda, 229, 242 ; characters of, 244 ; 

 parasitic forms of, 245 ; free forms of, 

 247. 



Nematophores, 124. 



Nemertes, 241. 



Nemertida, 230, 239 ; characters of, 240 ; 

 development of, 241. 



Neolimulus, 314. 



Neophron, 632. 



Nepa, 348, 349. 



Nephthys, 270. 



Nereidce, 270. 



Nereidea, 266. 



Nereis, 269. 



Neritidce, 412. 



Nervures,.335. 



Nesodon, 727. 



Nestor, 621. 



Neuropodium, 257, 267. 



Neuroptera, 335, 344; characters of, 

 350. 



Newts, 511, 517. 



Nidamental ribbon, 368. 



Night Heron, 610. 



Noctilionidce, 764. 



Noctiluca, 100. 



Nodosaria, 68, 70. 



Nonionina, 67. 



Nothosaurus, 562. 



Notidanus, 506. 



Notochord, 446. 



Notommatina, 251. 



Notonecta, 349. 



Notopodium, 257, 267. 



Notornis, 609. 



Nototrema, 511. 



N ucleobranchiata (see Heteropoda). 



Nucleolus of Paramcecium, 97. 



Nucleus, of Protozoa, 56 ; of Gregarina, 

 58 ; of Amoeba, 64 ; of Infusoria, 95, 96 ; 

 of Vorticella, 98 ; of the shell of M ol- 

 lusca, 369. 



Nudibranchiata, 369; characters of, 412, 

 413. 



Numenius, 611. 



Numida, 614. 



Nummulina, 71, 72, 77. 



Nummulitic limestone, 77. 



Nummulitidea, 74. 



Nuthetes; 554. 



Nutria, 745. 



Nyctereutes, 748. 



Nycteridce, 764. 



Nycteris, 764. 



Nycticebidce, 774. 



Nyctwebus, 774. 



Nycticorax, 610. 



Nyctipithecm, 777. 



Nymph, 341. 



Nymphon, 319. 



Oceanactis, 155, 180. 



Oceanic Hydrozoa, 131 ; distribution of, 

 in space, 150. 



Ocelli, of Medusae, 129 ; of Echinoidea, 

 195; of Asteroidea, 204; of Planarida, 

 240 ; of Rotifera, 251 ; of Annelida, 259 ; 

 of Chcetognatha, 272 ; of Limulus, 300 ; 

 ofArachnida, 319 ; of Myriapoda, 329 ; 

 of Insecta, 340 ; of Tunicata, 383 ; of 

 Lamellibranchiata, 368 ; of Gastero- 

 poda, 406. 



Octacnemus, 387. 



Octodon, 756. 



Octodontidce, 756, 760. 



Octopoda, 427. 



Octopodidce, 427. 



Octopus, 423, 435. 



Oculinidce, 164. 



Ocydromus, 612. 



Ocypoda, 311. 



Odontaspis, 506. 



Odontoceti, 685, 688. 



Odontolcce, 634. 



Odontophora, 396, 405. 



Odontophore, 396, 405, 407, 417, 421. 



Odontopteryx, 583, 607. 



Odontornithes, 584, 594, 634. 



Odontotormce, 634. 



CKdicnemus, 612. 



(Edipoda, 350. 



Oidemia, 606. 



Oldhamia, 150, 380. 



Oligochteta, 262, 263. 



Oligoporus, 201, 224. 



Omnivora ( Ungulata), 704. 



Omphyma, 175. 



Onager, 701. 



Onchuna, 284. 



Onchus, 505. 



Oncidiadce, 415. 



Oncinolabidce, 221. 



Oniscus, 305. 



Ontogenesis, 22. 



Onychophora, 329, 331, 332. 



Onychoteuthis, 419, 435. 



Oflcyst, 375. 



Operculata, 415. 



Operculum, of Balanidce, 289 ; of Gaster- 

 opoda, 406 ; of Fishes, 464. 



Ophiderpeton, 523. 



Opkidia, 530; general characters of, 537 

 e seg-.; divisions of, 541 ; distribution 

 of, in time, 544. 



Ophidobatrachia, 513. 



Ophiocoina, 207. 



Ophiomorpha, 513. 



Ophisaurus, 548. 



Ophiura, 207. 



OpkiuridcK, 207. 



Ophiuroidea, 192 ; general characters of, 

 205; families of, 207; distribution of, 

 in space, 222 ; in time, 224. 



Opisthobranchiata, 411, 412, 415. 



Opisthoccelia (Crocodilia), 557, 558. 



Opisthodelphys, 522. 



Opossum, 664, 666. 



Opossum-shrimp, 306. 



Orang-utan, 780, 781. 



Orbitoides, 77. 



Orbitulitidea, 74. 



Orca, 690. 



Orcella, 690. 



Oreaster, 224. 



Oreastridte. 205. 



Oreodon, 70S. 



