666 



INDEX. 



yaticidce, 313, 317. 



Naupliiis, 210. 



Nautilidoe, oliaracters of, 333; sections of, 



335; distribution of, in time, 337. 

 Nautiloid Forammiffera^ 55, 57. 

 Nautilus, Paper, 328; shell nf, 327, 328; 



Pearly, 330; anatomy of, 331; shell of, 



327, 331. 

 Nebalia, 218, 234. 

 Ncscto calyces, 93 ; stracture of, 95 ; in 



Calycophoridce, 95, 96; in MedusidoB, 



101 ; distinguished from the umbrella of 



the Lucema/Hdai 104. 

 Nectosac, 95. 



Needhara, moving filaments of, 325. 

 Nematelfnia, 165; characters of, 175. 

 Nematocysts, 80. 

 Nematodcb, 165, 166; characters of, 17^; 



parasitic forms of,177 ; free forms of, 1 79. 

 Nematophores, 82, 92. 

 NeiTiertes, 174. 

 IfetixrHda^ 166, 173; characters of, 174; 



development of 176. ' 

 Nereidce, 196. 

 Nereidea, 194. 

 Nereis, 196. 

 Nerita, 318. 

 Neritina, 318. 

 Neritidm, 314,.318. 

 Nervnres, 249. 

 Neuropodinm, 1S8. 

 Neuropteray 251, 261, 279. 

 Newts-, 412, 413. 

 Nidamental ribbon, 276. 

 Noctiluca, 76. 

 Ifodosaria, 54, 55. 

 Nothosaurus, 448. 

 Notidanus, 405. 

 Notochord, 347, 348. 

 Notommatina, 183. 

 NotoTiecta, 259. 

 Notopodium, 1S8. 

 Notoi-nis, 481. 



Nucleohranchiata, 315 (see Heteropodd). 

 Nucleolus of Paramcecium, 71, 72. 

 Nucleus, of Protozoa, 44 ; of Gregarina, 



46; of ATnceba, 50; of l-nfusoria, 71; 



of Vorticella, 73 ; of EchiTwdermataf 



152 (see Madreporifonu tubercle); of 



the shell of MoUusca, 277. 

 Nitdibranchiata, 310; characters of, 314, 



ilivisinns of, 319. 

 Numcnvus, 4S3. 

 Numida, 4S9. 

 Nummulitea, 56, 59, 60. 

 KiinmiuHtic limestone, 60. 

 Nyeticebidoi, GOl. 

 Nyeticebtts, GOl. 

 Nycticorax, 4S3, 

 Nympli, 254, 255. 

 Nymphon, 1'6'j. 



Obolus, 297. 



Oceanic Ilydrozoa, 93; divisions of, 03- 



100; distribution of, in space, 112. 

 Ocelli, of McduscBy 101; of EcMnoidea^ 



146; of AHteroidea,\b2\ of Ptanarkla, 



174: of Rot if era, 182; of Annelida, ISit; 



of Chcctognatha, 199; of Lnmtins, 221; 



cV Arachnida, 238; of Myrlnpoda, 246; 



of Inseola, 254 ; of Tunicata, 270 ; of 



Lamellfbranchiata, 270 ; of (xoslero- 



jtoda 309. 



Octopoda, 328, 334. 



Octopodidoe, 328, .'iSft 



Octopus, 325, 336. 



OcuUnidcBf 140. 



Ocypoda, 232. 



Odontaspis, 405. 



Odontoceti, 545, 648 



Odontophora, 300, 3uA, 



Odontophore, 309. 



Oedicnemus, 484. 



Oidemia, 479. 



Oldhamia, 113, 298. 



Oligoch(eta, 191, 192, 198. 



0;im, 317. 



Ommastrephes, 335. 



Omwiyora (//sii/w^ifa), 65S. 



Onchuna, 209. 



Onchua, 404. 



Oncidiadas, 317, 319. 



Oncidium, 319. 



Oniscits, 226. 



Onychoteuthis, 323, 335. 



Opercu^aia, 317, 319. 



Operculum, of ^a^an-it^ce, 212,214; of^ff 



fero^oda, 309; of Heteropoda, 315; of 



Pteropoda, 320 ; of Fishes, 365, 366. 

 ■ Ophicnnus, 158. 

 Opfiidiat 423; general characters of, 428- 



431 ; divisions of, 431 ; distribution of, 



in time, 434. 

 Ophidobatrachiai 409. 

 Ophiocoma, 154, 164. 

 02?7iioderma, 164. 

 Ophiolepis, 154, 164. 

 Ophiomorpha, 409. 

 Ophisaurus. 437. 

 Ophiura, 154. 

 Ophiutidea, 155. 

 Ophiuroidea, 143, 144; general charaotera 



of, 153; families of, 155; distribution of, 



in space, 162; in time, 163, 164. 

 Opisthohranchiata, 313, 314, 318. 

 Opisthocoslia (Crocodilia), 445. 

 Opossum, 534, 635. 

 Orang-outang, 605. 

 Orbifoides, 60. 

 OriiioZiies, 56. 

 Oreaster, 164. 

 Organ of Bojanus, 205, 304. 

 Organ-pipe Coral, 126. 

 Organs of the mouth of Insects, 260-252. 

 Oribatidm, 240. 

 Ornithodclpia, 623. 



Ornithorkynchus, 517, 520, 523, 527, 528. 

 Omithosauria, 450. 

 OrWtis, 296. 

 Orthisina, 296. 

 Orthoceras, 333, 334, 335, 337. 

 Ortkoceratidai, 335, 337. 

 Orthoptera, 250, 260, 273. 

 O/'ij/a;, 489. 

 Orycteropidce, 541, 

 Orycteropus, 541. 

 Osenla, of Sponges, 64, 09 : of Tapoworm, 



168. 

 Osteolepis, 391, 403. 

 Ostraciontideey 888. 

 Ostmcoday 20-S; char.ictcrs of, 216; di.s- 



tribution of, in time, 234. 

 OstracoBtei, 392, 403. 

 Osfrcrt, 305, 300. 

 Ostreidce, 305, 306. 

 Osti-ich, 4S4, 4S5. 



