610 



INDEX. 



Oractis, 189. 



Oral vacuole, 33. 



Orbiculina, 13. 



Orbitoides, 15. 



Orbitolites, 13. 



Orbulina, 11, 14. 



Orbulinella, 19. 



Orcadella, 17. 



Orchistonia, 134. 



Organ pipe coral, 178. 



Organidus, 178. 



Oria, 491. 



Orifice, 550. 



Orraer, 394. 



Orpiella, 416. 



Orthoceras, 444. 



Orthocoiicha, :!L'I>. 



Orthodon, 46. 



Orthouectidae. 240. 



Orthospora, 60. 



Oscarella, 95. 



Oseulum, 72. 



Osphradium, 320 ; of 

 Gastropoda, ' ' ' '> > '> : 

 Lanicllibranch, 333. 



Os sepiae, 417. 



Osti-ea, 330, 346. 



Ostreidae, 328, 338, 341. 

 :',42, 344. 



Othonia, 491. 



Otina, 415. 



Otoconia, 367. 



Otocyst, 214. 



Otocysts of Medusae, 

 115; of Polychaeta, 

 463. 



Otolith, 367. 



Otomesostomum, 219. 



Otoplana, 221. 



Otoporpa, 113. 



Ototyphlonemertes, 271. 



Ovicell, 550. 



Oviposition of Gastro- 

 poda, 3SO: of Oligo- 

 rliaeta, 506. 



Ovnla, 400. 



Ovum, 70. 



Owenia, 207, 484. 



Oxea, 82. 



Oxydromus, 477. 



Oxyhexact, 92. 



Qxyrrhis, 31. 



Oxysoma, 284. 



Oxytricha, 49. 



Oxyuris, 275, 279, 284. 



Oyster, 346. 



Ozobranchus, 526 



1'ai-liastrella, 94. 

 Pachychalina, 96. 

 Pachydrilus, 509. 



Pachymatisma, 94. 

 Pachypsammia, 196. 

 Pachyseris, 196. 

 Paedophylax, 476. 

 Paleae, 460. 

 Palephyra, 167. 

 Pali, 193. 

 Pallial bay, 326 ; cavity, 



319. 



Pallium, 319. 

 Palniicellaria, 566. 

 Palmyra, 478. 

 Palola, 481. 

 Palpacles, 139, 151. 

 Palp of Polychaeta, 459. 

 Palpou, 138, 139. 

 Paludir.-lla. 556. 567. 

 Paludina, 363, 376, 380, 



381, 383, 395, 399. 

 Paludoraus, 399. 

 Palythoa, 189. 

 Panartus, 23. 

 Pandat-a, 131. 

 Pandora, 349. 

 Pandorina, 32. 

 Pautlmlis, 478. 

 Paper-nautilus, 446. 

 Papyrula, 94 

 Paractidae, 188. 

 Paractiuia, 187. 

 Paractis, 187. 

 Paractins, 480. 

 Paradrilus, 511. 

 Paragastric canal, 201. 

 Paragorgia, 182. 

 Paralcyonium. 179. 

 Paramenia, 355. 

 Paramaecium, 40, 47. 

 Paramoeba, 29. 

 Paramuricea, 182. 

 Paramyluni, 28. 

 Paranephthya, 179. 

 Parantipathes. 190. 

 Parantlms, 187. 

 Parapedal commissure, 



409. 



Paraphellia, 187. 

 Parapodium, 357, 458. 

 Paraseisou, 310. 

 Parasmilia, 195. 

 Parasitic Gastropoda, 



386, 402 ; Lamellibran- 



chiata, 345 : Mollusca. 



323. 



Parazoantlius, 189. 

 Parenchyma. '209, 211. 

 Parenchymalia, 92. 

 Parenchytraeus, 509. 

 Parendrilus, 511. 

 Parieto- vaginal musclrs, 



550. 



Parisis, 182. 

 Parmacella, 416. 

 Paniiophorus, 361, 395. 

 Parmula, 96. 

 Paroral cilia, 49. 

 Parthenogenesis, 70. 

 Parthenogonidium, 32. 

 Pasythea, 564. 

 Patella, 360, 362, 367, 



369,371, 372,374,376, 



380, 385, 394. 

 Patellina, 14. 

 Patera, 167. 

 Pavonaria, 181. 

 Pavonina, 13. 

 Peachia, 188. 

 Pearl oyster, 327, 346. 

 Pearly-nautilus = 



Nautilus. 



Pcbrin-disease, 64, 68. 

 Pectanthis, 135. 

 Pectanthus asteroids, 



109. 

 Pecren, 331, 332, 333, 



334, 341, 342, 347. 

 Pectinaria, 462. 486. 

 Pectinatella, 568. 

 Pectinia, 195. 

 Pectinibranchiata, 395. 

 Pectinidae, Si's. 

 Pectis, 135. 

 Pectuneulus, 333, 345. 

 Pectyllis, 135. 

 Pedal ganglion, 319 : 



gland. 357. 

 Pedalion, 302, 310. 

 Pedetes, 309. 

 Pedicellina, 572. 

 Pedipes, 415. 

 Pedum, 347. 

 Pegantha, 136. 

 Pegasia, 136. 

 Pelagia, 167. 

 Pelagobia, 479. 

 Pelagonemertes, 266,270, 



271. 



Pelecypoda, 324. 

 Peiodera. 290. 

 Pelodrilus, 504, 508. 

 Pelodytes, 277, 280. 

 Pelogenia, 478. 

 Peloinyxa, 11. 

 PeloscoJex, 508. 

 Pelosina, 13. 

 Pelta, 404, 405, 406. 

 Peirimatodiscus, -'^. 

 Pen. 425. 

 Penis, 215 ; of Gastro- 



poda, 378. 

 IVimaria. 130. 

 IVnnatula, 181. 



