INDEX. 



431 



Odontornithes, 356 

 (Eneis, 267 



(Esophageal commissure, 184 

 CEsophagus, 305 

 Oil-bottle beetle, 253 

 Oil-glands, 350 

 Olfactory lobes, 28 

 Olfactory membrane, 21 

 Olfactory nerve, 20, 299 

 Olfactory organs, 301 

 Olfactory tract, 20 

 Oligoctose, 187 

 Olive-shells, 200 

 Olynthus, 158 

 Omenta, 17 

 Omosternum, 37 

 Opercular bones, 29 

 Operculum, 24, 198, 308 

 Ophidia, 347 

 Ophiopholis, 278 

 Ophiuroidea, 278 

 Opisthobranchia, 200 

 Opisthocoelous, 292 

 Opossum, 371 

 Optic ganglion, 107 

 Optic lobes, 20, 28, 299 

 Optic nerve, 20, 300 

 Optic thalamus, 20 

 Oral, 276 

 Oral surface, 110 

 Orang-utan, 392 

 Orbit, 46 

 Order, 143 



Organ of Bojanus, 100 

 Organ of Corti, 366 

 Organs, 154, 156 

 Origin of species, 414 

 Orioles, 363 

 Ornithorhynchus, 369 

 Ornithurae, 356 

 Orthoceratites, 211 

 Orth^ptera, 243 

 Oscines, 361 

 Osculum, 158 

 Ossification, 293 

 Ostia of heart, 70 

 Ostium, 130 

 Ostracoda, 224 

 Ostriches, 356 



Otoliths, 302 

 Otter, 388 

 Ovary, 315 

 Oviduct, 34 



Ovipositor, 76, 238, 253 

 Ox-bot, 268 

 Ox-warble, 268 

 Oyster, dissection of, 102 

 Oysters, 204 



Pachydermata, 384 



Pacific region, 411 



Palsearctic region, 409, 411 



Palate, 60 



Palatine bone, 39 



Paleozoic age, 413 



Pallial line, 101 



Pallial sinus, 101 



Palpi of clam, 99 



Palpus, 79 



Pancreas , 17, 34, 55 



Pangolin, 373, 374 



Panther, 388 



Paper nautilus, 209, 212 



Paramsecium, 134, 151 



Parapodia, 185 



Parasita, 261 



Parasphenoid bone, 39 



Parencephalon, 299 



Parieto-splanchnic ganglion, 100 



Parotid gland, CO 



Parrots, 361 



Parthenogenesis, 142 



Passeres, 361 



Pearl-oyster, 205 



Pearls, 206 



Pearly Nautilus, 209 



Pea-weevil, 253 



Pecten, 205 



Pectoral fins, 16, 23 



Pectoral girdle, 18, 296 



Pedal ganglion, 100 



Pedata, 284 



Pelagic fauna, 412 



Pelvic girdle, 38, 296 



Pen, 107 



Pencil, 3 



Penguin, 358 



Pennaria, 123, 165 



