448 



Index. 



Onychoteuthida, 325. 

 Oocysts, 226. 

 Oophylax, 21. 

 Opalina, 68. 

 Opalinsea, 68. 

 Operculum, 225, 285. 

 Opercularia, 68. 

 Ophelia, 221. 

 Ophiacantha, 133. 

 Ophiarachna, 133. 

 Ophiarthrum, 133. 

 Ophidiaster, 187. 

 Ophidromus, 22 1. 

 Ophioblenna, 133. 

 Ophiocephalus, 163. 

 Ophiocnemis, 133. 

 Ophiocoma, 131. 

 Ophiocominrc, 133. 

 Ophiocrinus, 131. 

 ( )phiocU-n, 133. 

 Ophioderma, 133. 

 Ophiodennina?, 133. 

 Ophiolepinse, 133. 

 Ophioli-pis, 131. 

 Ophionutstix, 131. 

 Ophic- . 133. 



Opln 131. 



Ophi 133. 



( >phiopc-/.i, 133. 

 ()phi<colrx, 133. 

 ( )phioscolecina>, 133. 

 Ophio^toinu, I, 133. 

 Ophiothrix, 134. 

 Ophiura, 133. 

 Ophiuridae, 153. 

 Ophiui , 131. 



Ophrydidae, 70. 

 ( )])lirydiuin, 70. 

 Ophr ,71. 



Ophryoiviva, 71. 

 Ophryodendron, 70. 



Ophn . 71. 



Ophryoscolecida, 71. 

 Ophryoscolex, 71. 

 Opilio, 



Opilinnidio, 375. 

 Opistomum, i(>i. 

 O|)isthobranchiata, 280, 304. 

 Orbicula, 53, 247. 

 Orbis-radulae, 288. 

 Orbitelae, 375. 

 Orbitolites, 52. 

 Orbitoides, 55. 

 Orbulina, 54. 



Orbulinidae, 54. 

 Orchestia, 360. 

 Orcula, 153. 

 Order, 38. 

 Oreaster, 137. 

 Organ, 26. 

 Organ system, 10. 

 Organ-pipe coral, 120. 

 Oribates, 365. 

 Oribatidzc, 373. 

 Origin of species, 40. 

 Ornithomyia, 419. 

 Orthocerina, 54. 

 Orthocerus, 315. 

 Orthopteia, 403. 

 Orthostomum, 161. 

 Oscula, 71. 

 Osculina, 73. 

 Osmic acid, 16, 17. 

 Ossification, 18. 

 Osteoblasts, 18. 

 Ostracoda, 

 Ostni 



Otion, 345. 

 Otoca; 



. 50, 236, 265, 299. 

 Otoliths, 2,\ 



X 3- 

 unir-n, t>. 



34- 

 Ovipo 

 Ovulum, 308. 

 0\\cn, 324, 325. 

 Ox bones, 17. 



n, 7. 



Oxygnatha, 388. 

 Oxyrhynchus, 357. 



mata, 357. 

 Oxytricha, 72. 

 Oxytrit 



Oxyuris, i So, 185. 

 Oxyuridae, 185. 

 Oyster, 257, 259, 261, 267. 



Pachyniatisma, 77. 

 Pacific Ocean, 45. 

 Pacinian corpuscles, 23. 

 Packard, 396. 

 Pagenstccher, 2, 300. 

 Pagina, 281. 

 Paguridas, 356. 

 Pagurus, 356. 



