712 



INDEX 



Nuptial chamber, 469 



Nurses, 504 



Nutrition, 17 ; of Mastigophora, 46 ; of 

 Phytomastigina, 46, 47, 49 ; of Pro- 

 tozoa, 17, 18 ;of symbionts, 48. See 

 also Holophytic nutrition, Holozoic 

 nutrition, Saj^ophytic nutrition 



Nycteribia, 512 



Nyctiphanes, 403 ; tjorwegica, 403 



NyctotheruSy 109; cordiformis, 109 



Nymphon, 538, 540 



Nymphs, 455 



Obelia, 154; 151, 155, 156, 158 



Obhque fission, 45 



Obtect pupae, 456, 490 



Ochromonas, 50; 47, 51, 63 



Octobothrium, 218 



Octomitiis, see Hexainitus 



Octopoda, 589; 599 



Octopus, 589, 595, 598, 599, 601, 602 



Ocular plate, 641 



Ocypus, 495 ; olens, 493, 494 



Odonata, 472 ; 430, 444 



Odontoblasts, 557 



Odontocerum, 487 



Odontosyllis, 280 



Odynerus, 498 n., 503 



Oegopsida, 588 



Oenocytes, 439, 440 



Oesophageal bulbs, 248 



Oesophageal pouches, 287 



Oesophagus, see Alimentary canal 



Oikomonas, 63 ; termo, 62 



Oikopleura, 43, 680; albicans, 680 



Olenus cataractes, 323 



Olfactory hairs, 342 



Oligochaeta, 286; 261, 263, 301 



Oligolophus spinosus, 538 



Oligopod stage, 458, 459 



Oligotricha, no 



Olynthus, 1 17; 1 17 



Ommatidium, 310; 426 



Onchosphere, 228, 229, 230 



Onychophora, 317; 308. See also 



Peripatus 

 Onychopoda, 368 

 Oocysts, 22; of Gregarinidea*, 94, 



95, 97 

 Oodinium, 55 ; 43 ; pouched, 43 

 Oogamy, 31, 46 

 Ookinete, 91, 93, 98 

 Oostegites, 389; 393, 397, 401 

 Ootheca, 448 



Ootype, 211 



Oozooid, 679; 685 



Opalina, 106; 10, 28, 43, 107; ran- 

 arum, II, 27, 106 



Opalinidae, see Prociliata 



Opening (Aperture), Atrial, see 

 Atrial opening; Excretory, see Ex- 

 cretory organs, Renal openings ; 

 Genital, see Generative organs; of 

 Mantle cavity, see Mantle. See 

 also Anus, Mouth, Oscula, Ostia, 

 Pneumostome, Pores 



Operculum, 270 



Ophiocoma, 640 



Ophioglypha, 639 



Ophiopluteus, 632 



Ophiothrix, 640 



Ophiura, 639, 640 



Ophiuroidea, 638 ; 623, 625, 626, 627, 

 629, 630, 632 



Ophryocystis, 94; mesnili, 95 



Opisthobranchiata, 567; 553, 568 



Opisthosoma, 309 ; 515, 528, 530, 537. 

 See also Mesosoma, Metasoma 



Opisthoteuthis , 602; 589 



Optic lobes of Crustacea, 340 



Oral aspect (side, or surface), 143; 

 of Echinodermata, 623 



Oral cone, 150; 155, 158; disc, 182; 

 siphon, 669; valves, 655 



Organisms, 4 



Ornithodorus moubata, 537 



Orthoceras, 600 ; 600, 604 



Orthoptera, 466; 429, 432, 454 



Orthorrhapha, 509, 510 



Oscar ella, 127 



Oscinus frit, 512 



Oscula, of Porifera, 117, 119, 120; of 

 Radiolaria, 80, 83 



Osphradia, 565 



Ossicles, of Echinodermata, 626 ; 

 Adambulacral, 636 ; Ambulacral, 

 636, 638, 645 ; Basal, 656 ; Brachial, 

 656; Centrodorsal, 655, 656; Cir- 

 rhal, 656; Infero-marginal, 634; 

 of Holothuroidea, 648, 650; Pin- 

 nulary, 656; Radial, 656; Rosette, 

 656; Supero-marginal, 634. See 

 also Auriculae, Skeletal plates 



Ossicles, System of, in Asteroidea, 

 634; in Crinoidea, 656; in Echi- 

 noidea (plates), 641 ; in Holothu- 

 roidea (calcareous ring), 649, 650; 

 in Ophiuroidea, 638 



