INDEX 



551 



Nitzschia, 56, 73 



Norman, on Polyzoa, 475 



Norodonia, 492 



Notamia, 518, 526 



Noteus, 225 



Notholca, 225, 226 



Notocotyle, 73 



Notomastus, 331 ; chaetae, 268 



Notommata, 217, 224, 226 



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



224 

 Notophyllum, colour, 293 

 Notopodinni, 246, 247, 264, 265, 268 

 Notops, 200, 224 

 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, 4% 



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; O. tricuspis, 144, 161 



Omalostoma, 49 



Onchnesoma, 422, 423, 426, 430, 447 



Onchocotyle, 73 



Oncholaimus, 157 



Onchosphaera-larva of Cestodes, 87, 88 



Onuphin, 290 



Onuphis, 290, 318, 319 ; O. conchylega, 

 tube, 287 



Onychochaeta, 3SS ; 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, 482, 

 522, 524 



Opesia, 524 



Ophelia, 299, 332 ; eggs, 275 ; coelomic 

 corpuscles, 252 



Opheliidae, 258, 331 ; gill, 265 ; ciliated 

 pits, 272 



Ophiodromus, 308 ; O. flexuosus, 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, 110 ; of Polychaeta, 

 273 



Otomesostoma, 46, 4$ 



Otoplana, 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, 57 ; of 

 Diplozoon, 60 ; of Gyrodactylus, 61 ; of 

 Distomum macrostomum, 65 ; of Callio- 

 bothrium, 75 ; of Archigetes, 76 ; of 

 Schistocephalus, 86 ; of Rhopalura, 95 ; 

 of Myzostoma, 343 see also Reproduc- 

 tive organs 



Ovicell, in Cheilostomata, 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 



Oxysoma, 139, 142 



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

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

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

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

 hydrophili, O. megatyphlon, O. spiro- 

 theca, 142 



Paddle worm, 313 

 Paedogenesis, 151 

 Pagenstecher, on Nemertinea, 99 

 Pcdaemonetes, host of Nectonema, 174 

 Palaeonemertea, 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 Hermelli- 



formia, 306 ; of Syllidae, 307 

 Paludicella, 492, 494, 501, 5C2, 505, 518 



