INDEX 



597 





Olfactory lobe, 469 



nerve, 471 



organs, 115 

 Oligochseice, 278 

 Oligopyreme, 73 

 Oligosoma, 530 

 Oligotrochus, 308 

 Olividae, 334 

 Ommastrephes, 347 

 Omasus, 568 

 Ommalidia, 356 

 Oncosphasra, 251 

 Oniscus, 386 

 Ontogeny, 2 

 Oocyte, 71, 132 

 Ookinete, 183, 190 

 Oospores, 169 

 Ootype, 244 

 Opalina, 195 

 Opercular cleft, 502 

 Operculum, 285, 327 



of fishes, 497 

 Ophidia, 530 

 Ophioglypha, 299 

 Ophiopholis, 299 

 Ophisaurus, 530 

 Ophiurioidea, 298 

 Ophryodendron, 198 

 Ophryoscolex, 197 

 Opisthobranchia, 334 

 Opisthocoele, 455 

 Opisthopatus, 400 

 Opisthotic, 458 

 Opossum, 560 



shrimp, 376 

 Opoterodonta, 531 

 Optic cup, 477 



ganglion, 119, 476 



lobes, 470 



nerve, 471 



stalk, 477 



thalami, 469 



vesicle, 477 

 Orange scale, 430 

 Orang-utan, 574 

 Ora serrata, 121 

 Oralia, 292, 301 

 Orbitelaria, 396 

 Orbitosphenoid, 458 

 Orbitotemporal fossa, 522 

 Orb weavers, 396 

 Orchestia, 384 

 Organ-pipe coral, 230 

 Organs, 88 



animal, 90, no 



Organs, assimilation, 91 



auditory, 116 



of Bojanus, 321 



circulator)', 99 



of Corti, 478, 552 



electric, in 



excretory, 104 



Jacobson's, 475 



larval, 150 



of locomotion, no 



lyriform, 390 



olf actor}', 115, 474 



phosphorescent, 121 



respirator}', 96 



segmental, 105 



sensory, 114 



sexual, 107 



of smell, 115, 474 



systems of, 90 



tactile, 115 



of taste, 115, 474 



tympanal, 117 



vegetative, 90 



visual, nS 



urogenital, 109 

 Orioles, 544 

 Origin of species, 18 

 Ornithodelphia, 558 

 Ornithorhynchus, 559 

 Orohippus, 569 

 Oronasal groove, 475 

 Orthis, 290 

 Orthoceras, 346 

 Orthonectida, 200 

 Orthoneurous, 330 

 Orthoptera, 421 

 Orthopoda, 528 

 Orycteropus, 563 

 Oscaxella, 205 

 Oscines, 544 

 Osculum, 202 

 Os innominatum, 550 

 Osmerus, 510 

 Osphradium, 116, 312 

 Ossein, 77 



Ossicula auditus, 479 

 Ostariophysi, 510 

 Osteoblasts, 78 

 Ostia of heart, 103, 357 

 Ostium tubas, 487 

 Ostracoda, 371 

 Ostracodermi, 493, 512 

 Ostracoteuthis, 341 

 Ostrasida;, 323 

 Os transversum, ^22 



Ostriches, 542 

 Otaria, 565 

 Otica, 458 

 Otic capsule, 457 



ganglion, 473 

 Otis, 544 

 Otolith, 116 

 Otter, 565 

 Ovaries, 486 

 Ovary, histology of, 70 

 Ovibos, 569 

 Ovicells, 286 

 Oviducts, 109, 486 

 Oviparous, 151 

 Ovipositor, 413 

 Ovis, 569 

 Ovoid gland, 293 

 Ovo viviparous, 151 

 Ovum, 486 

 Owlet moths, 433 

 Owls, 544 

 Oyster crab, 382 

 Oysters, 323 

 .Qx warble, 431 

 Oxy-haemoglobin, 79 

 Oxyrhyncha, 382 

 Oxystomata, 382 

 Oxyuris, 266 



Pachyderm, 570 

 Pachydrilus, 279 

 Pachylemurida;, 573 

 Paddle fish, 508 

 Pasdogenesis, 129. 414 

 Paguridea, 380 

 Patechinoidea, 305 

 Palaemon, 380 

 Palaemonetes, 380 

 Pakeocranium, 455 

 Pakeocrinoidea, 302 

 Palaeotherium, 569 

 Palate, 475 

 Palatine bone, 461 

 Paleacrita, 433 

 Palinurus, 380 

 Pallial line, 318 



sinus, 318 

 Pallium, 311, 469 

 Palolo worm, 275 

 Palpus, 353, 377, 406 

 Paludicella, 287 

 Paludinidas, 334 

 Pancreas, 96, 481 

 Pandalus, 380 

 Par.dicn, 544 



