726 



INDEX 



Ophiotrichidae, G37. 

 Ophiura, 636, 

 Ophiurae, 635. 

 Ophluroidea, 633. 

 Opisthobranchlata, 495. 

 Oral disc, 132. 

 Oral groove, 49. 

 Oral palp, 565. 

 Oral papillae, 634. 

 Oral plates, 634. 

 Oral surface, 614. 

 Oral tentacles (in holo- 



thurians),646. 

 Orbicella, 148. 

 orbiculata (Helicina), 534. 

 orbiculatum (Didemnum), 



671. 

 Orchestia, 367. 

 Orchestiidae, 366. 

 Oreaster, 628. 

 Oreasteridae, 628. 

 oregonensis (Diaptomus), 



343. 

 Organs of Cuvier, 646. 

 Orxbata, 443. 

 Oribatidae, 442. 

 ornata (Amphitrite), 295. 

 ornata (Aricia), 292. 

 ornata (Floscularia), 233. 

 ornata (Nassula), 54. 

 ornatum (Scalpellum), 359 

 Oroperipatus, 463. 

 Orthoceras, 606. 

 Orthoneurous gastropods, 



494. 

 Orthurethra, 507, 514. 

 Orygmatobothrium, 196. 

 oryza (Cylichnella), 497. 

 Osculum, 72. 



oslerl (Sphyranura), 176. 

 Osphradium, 480. 

 Ostracoda, 352. 

 Ostrea, 574. 

 Ostreidae, 574. 

 ostreum (Pinnotheres), 



399. 

 Otoporpae, 121. 

 Ovalipes, 398. 

 ovalis (Livoneca), 375. 

 ovalis (Succinea), 518. 

 ovalis (Succinea), 519. 

 ovata (Boroe), 154. 

 ovata (Cryptomonas), 36. 

 ovata (Monosiga), 29. 

 ovata (Vertigo), 517. 

 Ovicell, 248. 

 Ovigerous legs, 458. 

 ovis (Psoroptes), 440. 

 Ovulum, 550. 

 ovum (Mertensia), 152. 

 ovum (Ovulum), 550. 

 Oxygyrus, 553. 



Oxyrhynclia. 395. 

 Oxyrrhis, 30. 

 Oxytricha, 62. 

 Oxytrichidae, 61. 

 Oxyuris, 225. 

 Oyster crab, 399. 

 Oyster drill, 556. 

 Oysters, 574. 



Pachylomerus, 416. 

 pachyurus (Copeus), 238. 

 Pacific palolo worm, 283. 

 pacifica (Phoronis), 271. 

 Paguridae, 393. 

 Pagurus, 393. 

 Palffimon, 387. 

 Palaimonetes, 386. 

 Palffimonidae, 386. 

 Paleonemertea, 205. 

 Palinuridae, 392. 

 Palinurus, 392. 

 Palisade worm, 224. 

 pallasi (Eichiurus), 315. 

 pallasiana (Lepralia), 258. 

 Pallene, 460. 

 Pallenidae, 460. 

 Pallets, 598. 

 Pallial line, 564. 

 Pallial sinus, 564. 

 palliata (Littorina), 540. 

 palliata (Polygyra), 521. 

 pallida (Loligo), 610. 

 pallida (Onchidoris), 502. 

 pallida (Syllis), 287. 

 pallidum (Treponema), 26. 

 palUdus 



(Asteracanthion), 632. 

 pallidus 



(Stauronereis),291. 

 Pallifera, 528. 

 pallipes (Eremobates), 408. 

 Palm crab, 393. 

 palmata (Acropora), 146. 

 palmata (Pista), 295. 

 Palolo worm, 283. 

 Palpal organ, 414. 

 Palpi, 414. 

 Palpigradi, 406. 

 Paludestrina, 543. 

 Paludicella, 261. 

 Paludicellidae, 261. 

 Paludicola, 165. 

 Paludina, 544. 

 Paludinidae, 543. 

 paludosa (Palaemonetes), 



387. 

 palustris (Attus), 434. 

 palustris (Helodrilus), 314. 

 palustris (Lymnjpa), 510. 

 palustris (Orchestia), 307. 

 palustris (Pelomyxa), 15. 

 Pamphagus, 20. 



pandallcola (Probopyrus), 



381. 

 Pandalus, 387. 

 Pandoridae, 600. 

 Pandorina, 37. 

 panicea (Halicondria), 83. 

 Panopeus, 397. 

 Pantopoda, 458. 

 papalis (Mitra), 560. 

 Paper nautilus, 612. 

 papulosa (Aeolis), 503. 

 papulosa (Molgula), 665. 

 papposus (Solaster), 630. 

 Papulae, 623. 

 Paractidae, 143. 

 Paractinopoda, 650. 

 Paractis, 143. 

 Paragonimus, 184. 

 Paragordius, 227. 

 Parajulus, 469. 

 parallelus (Ancylus), 513. 

 parallelus (Heliodiscus), 



523. 

 Paramecidae, 55. 

 Paramecium, 56. 

 Paramecium (Chilomonas), 



36. 

 Paramphistomidae, 182. 

 Paramphistomum, 182. 

 Paramylura, 31. 

 Paranais, 309. 

 Parapod, 465. 

 Parapodium, in annelids, 



277, 282; in mollusks, 



479. 

 Parapolia, 207. 

 parasitica (Glossiphonia), 



318. 

 parasiticum (Bicidium), 



142. 

 Parategastes, 348. 

 Pardosa, 433. 

 Parenchyma, 156. 

 Parietal lip and tooth (of 



snail shells), 506. 

 parma (Echinarachnius), 



644. 

 Parthenogenesis, in Ostra- 

 coda, 353 ; in Phyllopoda, 



333 ; in Rotifera, 231. 

 Parthenogonidia, 39. 

 partita (Styela), 666. 

 parva (Fredericia), 307. 

 parvula (Nais), 308. 

 parvus (Planorbis), 513. 

 Parypha, 104. 

 passerinus (Analges), 441. 

 Patella, 530. 

 Patelliform, 530. 

 patellina (Vorticella), 66. 

 patens (Condylostoma), 59. 

 patina (Acmaea), 530. 



