632 INDEX 



Nerve rings, of Echinodermata, 554; 

 of Medusae, 131, 132, 135, 



154 



Nervous system, 122; 121; of An- 

 nelida*, 228, 229, 230, 250, 254, 

 256, 261, 265; of Arachnida*, 452, 

 457, 459, 467 ; of Arthropoda, 274; 

 of Brachiopoda, 540 ; of Chaeto- 

 gnatha, 542; of Chordata, 582; of 

 Ciona, 596, 597, 599; of Coelente- 

 rata*, 128, 131, 132, 135, 154; 

 of Crustacea*, 303, 334, 340, 344, 

 350, 351, 355, 370; of Echinoder- 

 mata*, 554, 563, 570, 575, 580; 

 of Enteropneusta*, 587, 590; of 

 Insecta, 397; of Lithobiiis, 379; of 

 Mollusca*, 470, 474, 477, 479, 481 , 

 499, 507, 52o;of Nematoda, 215; 

 of Nemertea, 207 ; of Onycho- 

 phora, 286 ; of Platyhelminthes*, 

 174, 175, 190, 199; of Polyzoa, 

 530 ; of Rotifera, 209 



Neuropodium, 231 



Neuroptera, 425 



Nidamental glands, 517 



Noctiliica, 49; 43, 51 



Nodosaria, 71 



N. hispida, 9 



Non-cellular animals, 3 



Notochord, 584; of ascidian tadpole, 

 597; of Enteropneusta, 585, 587 



Notodelphys, 335 



Notonecta, 417 



Notopodium, 231 



Notostraca, 322; 317 



Nuchal sense organ, see Neck organ 



Nucleariae, 68 



Nuclei, in Metazoa and Protozoa, 

 3 ; of pansporoblasts, 93 ; of Pro- 

 tozoa, 18-23, 18; Plurality of, in 

 Protozoa, 6 ; Position of, in cho- 

 anocytes, 117 



Nucleoli, 19 



" Nucleus ", of Rhizocephala, 345 ; of 

 Thaliacea, 607 



Niicula, 507; 471, 501, 504 



Nuda, 173 



Nudibranchiata, 494 ; 479 



Nummulites laevigatus, 70, 71 



Nuptial chamber, 413 



Nutrition, 14 n.; of Mastigophora, 

 40; of Phytomastigina, 41, 44; of 

 Protozoa, 14; of symbionts, 43. See 

 also Holophytic nutrition, Holo- 



zoic nutrition. Saprophytic nutri- 

 tion 



Nyctiphanes, 361 



AT", norwegica, 361 



Nyctotherus, 102 



N. cordiformis, 103 



Nymphon, 466, 468 



Nymphs, 399 



Obelia, 133; 130, 134, 135, 137, 138, 



140, 152 

 Oblique fission, 40 

 Obtect pupae, 402 

 Ochromonas, 44; 41, 45, 56 

 Octohothriiim, 191 

 Octoniitiis, see Hexamitus 

 Octopoda, 513; 524 

 Octopus, 519; 513, 523, 524, 525, 526, 



527 

 Ocular plate, 564 

 Ocypus olens, 43 1 

 Odonata, 415; 386, 393 

 Odontoblasts, 485 

 Odontocerum, 426 

 Odynerus, 434 n. 

 Oegopsida, 513 

 Oenocytes, 391 

 Oesophageal bulbs, 218 

 Oesophageal pouches, 254 

 Oesophagus, see Alimentary canal 

 Oikomonas, 56 

 O. termo, 57 

 Oikopleura, 38, 601 

 O. albicans, 601 

 Olenus cataractes, 287 

 Olfactory hairs, 306 

 Oligochaeta, 252 ; 229, 267 

 Oligolophus spinosus, 466 

 Oligotricha, 102 

 Olynthus, no; no, in 

 Ommatidium, 274; 383 

 Onchosphere, 201, 202, 204 

 Onychophora, 281 ; 270 

 Oocysts, 18 ; of Gregarinidea, 88, 90, 



91 

 Oodmium, 49; 38 

 O. pouched, 38 

 Oogamy, 26, 27, 40 

 Ookinete, 85, 86 

 Oostegites, 349; 352, 355, 359 

 Ootheca, 397 

 Ootype, 185 

 Oozooid, 600; 603, 604 

 Opalina, 99; 6, 24, 38, 100 



