INDEX 



2S.~> 



Nephrops (Norway Lobster, " Crayfish "), 



129, 134 



Nephrostome, 116, 171, 173, 212 

 Nephrotome, 196, 212 

 Nereis, 114, 120, 122 

 Nerve cell, 78 



Nerves, Cranial, 188, 201, 202, (Fishes) 

 218, (Dogfish and Skate) 221, 

 (Birds) 241, (Mammals) 250 

 Peripheral, 201 



Sensory and motor, 202, 221 

 Spinal, 188, 201, 202 

 Nervous System, Development of, 200 



Sympathetic, 202, 236 

 of Amphioxus, 187~ 



,, ,, of Annelida, 115 



of Anodonta (Fresh- 



water Mussel), 174 

 ,, of Arenicola (Lobworm), 



121 



of Arthropoda, 126 

 of Astacus (Crayfish), 



135 



,. of Balanoglossus, 179 



of Birds, 241 

 of Craniata, 200,202 

 of Helix (Snail), 170 

 of Hirudo (Leech), 124 

 of Hydra, 78 



of Insecta, 138 



of Lumbricus (Earth- 



worm), 117 

 of Mollusca, 166 

 of Nematoda, 102 - 

 of Platyhelminthes, 89 

 of Eana (Frog), 236 

 of Raia (Skate), 221 

 ,. of Scyllium (Dogfish), 



221 

 of Taenia (Tapeworm), 



96 

 ofTunicata, 181, 183 



(of larva) 



of Vertebrata, 177 



Neural crest, 200 

 Neurenteric canal, 190 

 Newt (Triton), 231 

 Nictitating membrane, 205 

 Nose. See Olfactory organ. 

 Notochord of Amphioxus, 187, 191, 193 

 Balanoglossus, 179 



Notochord of Cyclostomata. 216 

 Fishes, 217 

 Tunicates, 181, 182 

 Vertebrates (Craniata), 1/7, 



193, 196 



Notoryctes (Marsupial "Mole"), 261, 267 

 Nucleus, 6, 27 ; kinetonucleus and 

 trophonucleus, 40 



Obelia, 75, 81, 83 



Ocelli, 83 



Odontophore, 170 



Oestridae (Bot-flies, Warble -flies), 144 



Oestrus (Sheep, Nasal-fly), 144 



Olfactory organ or nose, 203, 205 



Omentum, 245, 255 



Onchosphere (embryo), 98 



Oocyst or spore-cyst, 65 



Oocyte (immature ovum), 9 



Oogenesis, 9 



Ookinete, 65 



Ooze, Altantic or Globigerina, 34 ; 



Radiolarian, 35 

 Opalina, 21, 23, 53 

 Operculum of Fishes, 211 

 Opisthonephros, 213, 216 

 Opost-um (Didelphys), 261, 267 

 Orang-utan (Simia), 265, 274 

 Ornithorhynchus (Duckmole), 261, 266 

 Ossicles of ear, 206 

 Ostrich (Rhea, Struthio), 249 

 Otocyst or ear, 83, 131, 174, (statocyst) 

 182, (structure and development) 203, 

 205, (fishes) 218, (birds) 241, (mammals) 

 256 

 Ova or eggs of Birds, 247 



Craniata (Vertebrata), 214 

 Culicidae (Mosquitoes), 143 



Hydra, 80 



Lice, 154 



Mammals, 250 ; Mono- 

 tremes, 266 



Eana (Frog), 232 



Reptilia, 239 



Scyllium (Dogfish), 226 



Stegom.yia, 151 



Tapeworm, 98 



Ticks, 161 

 Ovary, 214 

 Oviduct, 213, 214 

 Ovum, 9 ; maturation of, 9 



