INDEX. 



691 



Ogmius, 369 l . 

 Ogmodon, 370 2 . 

 Ogmgrhinus, 627 2 . 

 Oil- bird, 47-2-\ 

 Oil gland, birds, 419. 

 Okapia, 590 1 . 

 Old-wife, 2361. 

 Olecranon, 49-J. 

 Olfactory lobes, 68. 

 Olfactory organ of Am- 



phioxus, 18 ; of fishes, 

 ' 78. 



Oligodon, 368 l . 

 Oligopleuridae, 213. 

 Oligorus, 235'. 

 Oligosarcus, 217 2 . 

 Olistherops, 238 1 . 

 Olm, 307 2 . 



Oinmatophoca, 627 2 . 

 Omomys, 653 1 . 

 Omosternum, 270. 

 Onchorhynchus, 216 1 . 

 Oneirodes, 246 1 . 

 Onychodactylus, 273, 



306 i. 



Onychodectes, 609 1 . 

 Onychodontidae, 175. 

 Onychogale, 535 2 . 

 Onychomys, 634 ] . 

 Onchus, 147, 262. 

 Opah, 228', 

 Operculum, Amphibia, 



279, 280 ; Dipnoi, 



249. 



Ophichthus, 225 1 . 

 Ophichthys, 223 1 , 225 1 . 

 Ophiderpeton, 315 1 . 

 Ophidia, 355. 

 Ophidium, 244 2 . 

 Ophiocephalus, 201, 210, 



232i. 



Ophiodes, 351 2 . 

 Ophiodon, 242 1 . 

 Ophiognomon, 352 2 . 

 Ophiomorus, 354 1 . 

 Ophiops, 353 2 . 

 Ophiopsis, 180. 

 Ophiopsiseps, 354 2 . 

 Ophioscion, 235 2 . 

 Ophisaurus, 351 2 . 

 Ophryoessa, 351 1 . 

 Ophrysia, 465 2 . 

 Ophthalmic ganglion, 



135. 

 Ophthalmicus profun- 



dus, 73, 135. 

 Ophthalmo sanrus, 395 1 . 

 Opisthocoolous, 161, 



317. 



Opisthocomus, 466 l . 

 Opisthoglypha, 368 2 . 

 Opisthognathus, 235-'. 

 Opisthomi, 245 J . 

 Opisthoneina, 214 2 . 

 Opisthopterus, 214 2 . 

 Opisthotropis, 367'. 

 Opossum, 539 1 . 

 Opsanus, 244 ' . 

 Opsariichthys, 220 1 . 

 Optic chiasma, 69. 

 Optic lobes, 67. 

 Optic thalami, 69. 

 Optic vesicles, 68. 

 Or. = Oriental. 

 Oral cirri, 11, 19. 

 Oral hood, 19. 

 Orang-utan, 661 1 . 



Orcella, 563 2 . 

 Orcynus, 238 2 . 

 Oreas, 591 1. 

 Oreinomys, 633 2 . 

 Oreinus, 219 1 . 

 Oreobatrachus, 313 1 . 

 Oreodon, 579, 585 1 . 

 Oreonectes, 221 '. 

 Oreophasis, 465 1. 

 Oreophrynella, 312 1 . 

 Oreopithecus, 659 1 . 

 Oreopsittacus, 470 2 . 

 Oreosaurus, 352 2 . 

 Oreosoma, 240 1 . 

 Oreotragus, 590 2 . 

 Orestias, 227 1 . 

 Oriole, American, 478 1 , 



golden, 477 1 . 

 Oriolus, 477i. 

 Ornithochirus, 390 2 . 

 Ornithodelphia, 525. 

 Ornithopoda, 386. 

 Ornithorhynchus, 490, 



494, 529, 526. 

 Ornithoscelida, 383. 

 Ornithosuchus, 382 1 . 

 Orodus, 151i. 

 Orohippus, 599 1 . 

 Oronasal groove, 120. 

 Ortalis, 465 1 . 

 Orthacodus, 152 1 . 

 Orthagoriscus, 92, 183, 



198, 195, 223, 247 2 . 

 Orthodon, 220 1 . 

 Orthognathism, 489. 

 Orthopoda, 386. 

 Orthopristis, 236 1 . 

 Orthostichous, 56. 

 Orthostomus, 241 1. 

 Orycteropus, 542, 549 1 . 



Oryx, 591 1. 



Oryzomys, 634'. 



Oryzoryctes, 641 ] . 



Os" cloacae, 342. 



Os coccygis, 265. 



Os cines, 475. 



Os innominatum, 491. 



Osmerus, 208, 216 1 . 



Os penis, 515. 



Osphromenus, 237 l . 



Os planum, 486. 



Osprey, 464 1 . 



Osseous tissue of Elas- 

 mobranchii, 122. 



Ostariophysi, 216 2 . 



Osteobrama, 220 2 . 



Osteochilus, 219 2 . 



Osteoderms, 317, liz- 

 ards, 337. 



Osteogeniosus, 221 2 . 



Osteoslossum, 215 1 . 



OsteoTaemus, 383 2 . 



Osteolepis, 175. 



Osteostraci, 261. 



Ostracion, 246, 247 1 . 



Ostracodermi, 260. 



Ostrich, 457 2 . 



Otaria, 626 1 . 



Otidiphaps, 469 1 . 



Otis, 466 2 . 



Otocoelus, 400 1 . 



Otocryptis, 350 2 . 



Otocyon, 622 1 . 



Otogyps, 463 2 . 



Otolemur, 652 1 . 



Otolithus, 235 2 . 



Otomys, 633 2 . 



Otonycteris, 647 2 . 



Otophidium, 244 2 . 



Otrynter, 236 1 . 



Otter, 6241. 



Ouacaria, 657 1 . 



Oudenodon., 401 2 . 



Oulachan, 216 2 . 



Ounce, 619i. 

 Ourebia, 590 2 . 



Ova, Mammalia, 518. 

 Ovary, Mammalia, 515. 

 Ovibos, 591 2 . 

 Oviduct, 87 ; Dipnoi, 



256. 



Oviposition, Amphibia, 

 296 ; Amphioxus, 30. 

 Ovis, 591 2 . 

 Ovulation, Mammalia, 



517. 



Ovum, Mammalia, 480 ; 

 Vertcbrata, 50. 



Owl, barn, 47 1 2 ; fern, 



