INDEX. 



843 



PAGE 



Neuroblast .... 208 



Neuro-muscular cells . . 43 



Neuropodium . . .219 



Neuroptera . . 344 



Newts ... . 586 



Nictitating membrane of eye . 479 



Noctiluca .... 107 



Nomarthra . . . .728 



Nose, the . . . 474 



ofMyxine . . . 480 



Notochord of Balanoglossus . 417 



,, origin of . . 463 



,, sheath of . . 463 



Notommata .... 234 



Notopodium . . . .219 



Notoryctes .... 723 



Nucleus .... 45 



,, division of . -47 



Nucula 406 



Nudibranchs . . . 402 



Nummulites . . . .106 

 Nymph. . -337 



Nymphon .... 363 



OBELIA .... 163 

 Obstetric toad . . .589 

 Ocellatce . . . .146 



Ocelli 327 



Octanemus .... 438 

 Octocoralla . . . .158 

 Octopoda . . . .413 

 Octopus . . . .413 

 Oculomotor nerve . . .472 

 Odonata .... 322 

 Odontoceti .... 747 

 Odontoid process . . . 675 

 Odontolcae .... 663 

 Odontophora (see Glossophora) 398 

 Odontophore of Cephalopoda 413 

 ,, of snail . . 370 



CEsophagus of Vertebrates . 481 

 Oikapleura .... 437 

 Olfactory lobes . . . 467 

 ,, nerves . . . 472 

 ,, tracts . . . 683 

 Oligochseta . . . 197, 218 

 Omentum .... 646 

 Ommastrephes . . .413 

 Oniscus . . . .291 

 Ontogeny . . . 71 



PAGE 



Oocyst ..... 102 

 Ooze, Atlantic . . .106 

 Opalina . . . 107, III 

 Opalinopsis . . . . 1 1 1 

 Operculum of Gasteropods . 368 

 ,, of Limulus . . 359 



,, of scorpion . . 349 



,, of Teleostei . . 534 

 Ophidia .... 607 

 Ophiocoma .... 249 

 Ophiopholis .... 248 

 Ophiothrix .... 249 

 Ophiuroidea .... 248 

 Ophryodendron . . . 108 

 Opisthobranchs . . . 401 

 Opisthoccelous . . 551 



Opisthocomus . . 662, 665 

 Opossums .... 722 

 Optic chiasma . . .5*7 

 ,, foramen . . . 677 

 ,, lobes .... 469 

 ,, nerves. . . . 467 

 , , thalami . . . 467 

 ,, ,, structures con- 



nected with . . . 470 

 Orang ..... 767 



Orca 747 



Orchestia .... 292 



Organs ..... 36 



,, origin of . .69 



,, rudimentary . . 39 



Oriental region . . . 804 



Ornithodelphia . . .716 



Ornithorhynchus . . .716 



Orthoptera .... 322 



Orycteropus .... 728 



Oscarella . . . .125 



Osculum . . . .125 



Osphradium of Molluscs . 379 



Ossicles of ear . . . 476 



Osteoblasts .... 42 



Ostracoda . . . 284, 286 



Ostracodermi . . . 507 



Ostrea ..... 407 



Ostriches .... 662 



Otaria ..... 756 



Otocyon .... 754 



; Otocysts = Otoliths . . 437 



i Otoliths of Vertebrates . -475 



I Otter 755 



