INDEX 



551 



Nitzschia, 56, 73 



Normau, on Polyzoa, 475 



Norodonia, 492 



Xotamia, 518, 526 



Xoteus, 225 



Xotholca, 225, 226 



Notocotyle, 73 



Notomastus, 331 ; chaetae, 268 



Nutommata, 217, 224, 226 



Notommatidae, 200, 205, 207, 215, 223, 



A 



Notophyllum, colour, 293 

 Notopodiuni, 246, 247, 264, 265, 268 

 JVotops, 200, 234 

 Notopygos, 259 

 Nuchal cirri of Eunicidae, 318 ; Nuchal 



organ see Ciliated pits 



OCNERODRILUS, 383 



Octobothrium, 56, 73 



Octochaetus, 358, 384 



Octocotylinae, 73 



Octotrocha, 221 



Odontosyllis, reproduction of, 278 ; as 

 host, 297 



Oecistes, 205, 206, 221 



Oenonites, 302 



Oesophageal glands, 271, 358 



Ogmogaster, 73 



Oka, on Hirudinea, 399 f. ; on Polyzoa, 

 500 



Olfactory pits, in Polyclads, 26 ; in Triclads, 

 36 



Oligocelis, 42 



Oligochaeta, 241, 347 f. ; external char- 

 acters, 348 ; body -wall, 349 ; chaetae, 

 350, 351 ; branchiae, 352 ; nervous 

 system, 353 ; sense-organs, 354 ; coelom 

 and vascular system, 355 ; excretory 

 organs, 356 ; alimentary canal, 358 ; 

 reproductive organs, 360 ; habitat, 365 ; 

 phosphorescence, 368 ; distribution, 369 ; 

 classification, 373 ; Rotifers parasitic on, 

 227 



Oligocladus, 19, 22 



Oligognathus, 297 



Ollulanus, 142; 0. tricuspis, 144, 161 



Omalostoma, 49 



Oiichnesoma, 422, 423, 426, 430, 447 



Onchocotyle, 73 



Oncholaimus, 157 



Onchosphaera-larva of Cestodes, 87, 88 



Onuphin, 290 



Onuphis, 290, 318, 319 ; 0. conchyleya, 

 tube, 287 



Onychochaeta, 388 ; chaeta, 351 



Onyx, 131 



Ootype, in Polystomum, 59 



Operculum, of Serpulidae, 261, 276, 339 ; 

 of Spirorbis, .as brood-pouch, 261, 276 ; 

 of Cheilostomata, 466, 477, 481, 4S2, 

 522, 524 



Opesia, 524 



Ophelia, 299, 332 ; eggs, 275 ; coelomic 

 corpuscles, 252 



Opheliidae, 258, 331 ; gill, 265 ; ciliated 

 pits, 272 



Ophiodromus, 308 ; 0. Jlexuosus, parasitic, 

 297 



Ophryotrocha, 319, 320 ; pelagic, 291 ; 

 genital organs, 274 



Opisthotrema, 73 



Opistoma, 50 



Orbigny, D', on Polyzoa, 519, 520 



Orifice, of zooecium, 466, 469, 470, 524 ; 

 secondary, 522, 524 



Orley, on classification of Nematodes, 137 



Orthonectidae, 13, 92, 94 f. 



Otocyst (and Otolith), of Turbellaria, 26 : 

 of Nemertinea, 106, 1 10 ; of Polychaetn, 

 273 



Otomesostoma, 46, 49 



Otoj)lana, 50 



Oudemans, on Nemertinea, 108 



Ovary (and Oviduct), of Leptoplana, 11, 14, 

 16 ; of Polyclads, 27 ; of Planaria, 38, 

 39 ; of Rhabdocoelida, 47 ; of Temno- 

 cephala, 54 ; of Polystomatidae, 67 ; of 

 Uiplozoon, 60 ; of Gyrodactylus, 61 ; of 

 Distamum macrostomum, 65 ; of Callio- 

 bothrium, 76 ; of Archigetes, 76 ; of 

 Schistocephalus, 86 ; of Rhop(dura, 96 ; 

 of Myzostoma, 343 see also Reproduc- 

 tive organs 



Ovicell, in Clieilostomata, 466, 466, 468, 

 481, 482, 484, 522 f., 525 ; in Cyclo- 

 stomata, 479, 480, 521, 525 



Oviduct see Ovary 



Owenia, 325 



Ox, parasites of, 79, 83, 125, 139, 140, 143 



Oxysmna, 139, 142 



Oxyuris, 129, 131, 135, 139, 141, 160 ; 0. 

 ambigua, 141 ; 0. curvula, 141, 163 ; 

 0. diesingi, 141, 142 ; O, vermicularis, 

 141, 163; 0. blattae, 0. Uatticola, O. 

 hydrophtti, 0. megatyphlon, 0. spiro- 

 theca, 142 



PADDLE WORM, 313 

 Paedogenesis, 151 

 Pageustecher, on Nemertinea, 99 

 Palaemo>ietes, host of Xectonema, 174 

 Palaeouemertea, 109, 112; characters, 111 ; 



development, 113 

 Palaeozoic, Serpulidae, 301 ; Eunicidae. 



302 ; Polyzoa, 520 

 Paleae, of Sabellaria, 267 

 Palmicellaria, 527, 528 

 Palolo viridis, as food, 297 

 Palps, of Nereis, 248, 255 ; nerves to, 254 ; 



of Polychaeta, 260 f. ; development of, 



in Sabelliformia, 275 ; of Hennelli- 



formia, 306 ; of Syllidae, 307 

 Paliulicella, 492, 494, 501 , 5C2, 505, SIS 



