INDEX 



959 



Ophryodendron, 135. 

 Ophthalmosaurus, 720. 

 Opilioacarus, 432. 

 Opilionina, 417. 

 Opisthobranchs, 474. 

 Opisthocoelous, 639, 726. 

 Opisthopatus, 366. 

 Opisthophthalmus, 416. 

 Opossums, 837. 

 Optic chiasma, 553, 798. 



— cup, 553. 



— development of, 85. 



— foramen, 791. 



— lobes, 542. 



— nerves, 545, 553. 



— thalami, 540. 



— vesicle, 553. 

 Orang, 885, 887. 



utan, skull of, 886. 



Orca, 863, 864. 



Orchestia, 352. 



Oreocephalus, 702. 



Organising factor in development, 84. 



Organogenesis, 87. 



Organs, 42. 



— classification of, 46. 



— differentiation of, 85. 



— origin of, 83. 



— rudimentary, 45. 



— substitution of, 45. 

 Oriental region, 905. 



— sore, parasite of, 149. 

 Ornithodelphia, 3, 833. 

 Omithorhynchus, 2, 3, 776, 833. 

 Orthoceras, 485, 487. 

 Orthonectid, a female, 166. 

 Orthonectidae, 166. 

 Orthoptera, 384, 407. 

 Orycteropodidae, 845. 

 Orycteropus, 827, 843, 845. 

 Oscarella, 157, 162, 164. 



— development of, 162. 

 Osculum, 154. 



Osphradium of Molluscs, 435, 439, 450. 



Ossicles of ear, 550, 779, 793. 



Osteoblasts, 48. 



Osteolepis, 636. 



Ostracoda, 341. 



Ostracodermi, 586. 



Ostrea, 480. 



Ostrich, dorsal vertebra of, 728. 



— pectoral girdle of, 772. 

 Ostriches, 4, 770. 

 Otaria, 874, 



Otariidas, 873. 

 Otocyon, 872. 

 Otocysts = Otoliths, 185, 206, 439, 



— of snail, 439. 

 Otoliths of crayfish, 327. 



— of Vertebrates, 549. 

 Otter, 873- 



Ova of Anodonta, 454, 455. 



— of Birds, 764. 



— of cockroach, 376. 



— of crayfish, 334. 



— of earthworm, 254. 



Ova of Echinoderms, 314. 



— of Fishes, 628. 



— of fluke, 218. 



— of frog, 670. 



— of Hydra, 179. 



— of Monotreraes, 783, 833. 



— of Myxine, 578. 



— of Peripatus, 365. 



— of Placental Mammals, 783. 



— of Reptilia, 717. 



— of scorpion, 416. 



— of Sepia, 465, 465. 



— of Vertebrates, 571. 

 Ovary, 57r. 



Oviducal gland of skate, 607. 

 Oviduct of Vertebrates, 568, 671. 

 Oviparous Vertebrates, 572, 819. 

 Ovis. 852. 

 Ovists, 72. 



Ovo-testis of snail, 443. 

 Ovo-viviparous Vertebrates, 572. 

 Ovulation, 818. 

 Ovum, 63, 66. 



— detailed structure of, 67. 



— manamalian, 572. 



— maturation of the, 69, 571. 



— membranes around the Vertebrate, 571. 



— of insects, 395. 



— theory, 85. 

 Oxidation in animals, 35. 



— in living cells, 26. 

 Oxyuris, 242. 

 Oyster, 8, 479. 

 Ozobranchus, 280. 



Pachymatisma, 158, 164. 



Pacinian corpuscles, 736. 



Pedogenesis, 678. 



Pagurus, 353. 



Palaearctic region, 905. 



Palcemon, 353. 



Palseohatteria, 686. 



Palaeoniscus, 637. 



Palaeontological series, 100. 



Palaeontology, 98. 



Palaeospondylus, 6, 574, 585,585. 



Palaeostraca, 412, 426. 



Palaeotherium, 856. 



Palaeotragus, 852. 



Palato-pterygo quadrate cartilage, 534. 



Palinurus, 320, 353. 



Palisade worm, 240, 



Pallium, 433. 



Palmipes, 292, 298. 



Palp, 323, 372. 



Paludicella, 287. 



Paludina, 100. 



— larva of, 445. 

 Pancreas, 556. 

 Pancreatic secretion, 30. 

 Panda, 873. 

 Pandalus, 353. 



Pangolin, 813, 829, 843, 845. 

 Panmixia, 899. 

 Panniculus adiposus, 786. 



— camosus, 786. 



