INDEX. 



6l 5 



Neuroptera, 244, 252. 



Newts, 386, 387. 



Nidaruental ribbon, 255. 



Noctiluca, 72. 



Nodosaria, 52, 53. 



Nothosaurus, 418. 



Notidanus, 380. 



Notochord, 323, 325. 



Notommatina, 175. 



Notonecta, 243. 



Notopoclium, 179. 



Notornis, 449. 



Nucleobranchiata,- 291 (see Heteropoda). 



Nucleolus of Paramoecium, 67. 



Nucleus of Protozoa, 42 ; of Amoeba, 47, 

 48 ; of G-regarina, 44 ; of Paramcecium, 

 67 ; of Vorticella, 69 ; of Echinoder- 

 mata, 145 (see Madreporiform tubercle) ; 

 of the shell of Mollusca, 256, 289. 



Nudibranchiata, 256, 288 ; characters of, 

 292 ; divisions of, 296. 



Numenius, 450. 



Numida, 454. 



Nummulites, 53, 56, 57. 



Nummulitic Limestone, 57. 



Nycticebidce, 553. 



Nymph, 239. 



Nymphon, 225. 



; 275. 



Oceanic Hydrozoa, 89 ; divisions of, 89 ; 

 distribution of, in space, 108. 



Ocelli, of Medusce, 97; of EcMnoidea, 

 139; of Asteroidea, 146; of Planarida, 

 167 ; of Rotifera, 175 ; of Annelida, 

 ISO ; of Chcetognatha, 189 ; of Limulus, 

 209; ofArachnida, 224; of Myriapoda, 

 231 ; of Insecta, 238 ; of Tunicata, 255, 

 268 ; of Lamellibranchiata, 255. 



Octopoda, 305, 311. 



Octopodidce, 305. 



Octopus, 302, 303, 311. 



Oculinidce, 134. 



Odontaspis, 380. 



Odontoceti, 505, 509. 



Odontophora, 278, 286. 



Odontophore, 287. 



Oedicnemus, 450. 

 *0ldhamia, 108, 276. 



Oligochceta, 182, 188. 



OZiwa, 294. 



Ommastrephes, 311. 



Omnivora (Ungulata), 516. 



Onchuna, 199. 



Onchus, 379. 



Oncidiadcv, 294, 296. 



Oncidium, 296. 



Oniscus, 213. 



Onychoteuthis, 300, 311. 



Opemilata, 294, 296. 



Operculum, of Balanidce, 202 ; of Gaster- 

 opoda, 287 ; of Heteropoda, 293 ; of 

 Pteropoda, 297 ; of Fishes, 344, 349. 



Ophidia, 397 ; general characters of, 402- 

 405 ; divisions of, 405 ; distribution of, 

 in time, 407. 



Ophidobatrachia, 384. 



Ophiocoma, 157. 



Ophioderma, 157. 



Ophiolepis, 147. 



Ophiomorpha, 384. 



Ophiura, 147, 14*. 



Ophiuridea, 148. 



Ophiuroidea, 137, 138 ; general characters 

 of, 146 ; families of, 148 ; distribution of, 

 in space, 155 ; in time, 157. 



Opisthobranchiata, 291, 292, 296. 



Opisthoccelia (Crocodilia), 415. 



Opossum, 495, 496. 



Orang-outang, 557. 



Orbitoides, 57. 



Orbitolites, 53. 



Greasier, 157 



Organ of Bojanus, 273, 282. 



Organ-pipe Coral, 120. 



Organs of the mouth of Insects, 235, 236. 



Ornithodelphia, 485, 489. 



Ornithorhynchus, 479, 482, 485, 489, 490. 



OrMis, 274. 



Orthisina, 274. 



Orthoceras, 310, 211, 312, 314. 



Orthoceratidce, 312, 314. 



Orthoptera, 242, 243, 244. 



Orycteropidoe, 501. 



Orycteropus, 498, 501. 



Oscula, of Sponges, 60, 61 ; of Tape-worm, 

 161. 



Osteolepis, 367, 378. 



Ostraciontidce, 363. 



Ostracoda, 198 ; characters of, 205 ; dis- 

 tribution of, in time, 220. 



Ostracostei, 368. 



OsZrea, 283, 284. 



Ostreidce. 283, 284. 



Ostrich, 451, 452. 



Otaria, 533. 



OttdO!, 450. 



Otter, 537. 



Oudenodon, 419. 



Ovarian vesicles, of Sertularida, 87. 



Otfibos, 526. 



Owidce, 524, 525. 



Ovipositor, 235, 249. 



Ovis, 525. 



Ovulum, 294. 



Owls, 464, 465. 



Oxen, 518, 520, 525. 



Oxyuris, 170. 



Pachydermata, 511, 512. 

 Paddle-fish, 368. 



Pcecilopoda, 209 (see Xiphosurd). 

 Paguridce, 217. 

 Palceaster, 157. 

 Pt'lcjechinus, 157. 

 Palceocoryne, 108. 

 Palceodiscus, 157. 

 Palceophis, 407. 

 Palceospongia, 64. 

 Palocotherium, 515, 564. 

 Palapteryx, 470. 

 Pali (Corals), 115. 

 Pallial line, 280, 281. 

 Pallial sinus, 282. 

 Palliobranchiata, 270. 

 Pallium (see Mantle). 

 Paludicella, 263. 

 Paludicellea, 265. 

 Paludina, 295, 313. 

 Paludinidce, 292, 295. 

 Paludomus, 295. 

 Palythoa, 117. 

 Pamphagus, 49. 

 Pangolin, 501. 



