INDEX 



653 



Oo.s|iliere, 31 ; formation of, in ^letazoa, 

 75 n. ; of Gregarinidaceae, 99, 100 ; of 

 Coccidiaceae, 100 f. ; of Acystosporidae, 

 104 f. 



Oospore ( = zygotospore), from bisexunl 

 syngamy, 100 ; of Volvox globatm; 127 f. 



Ooze, Globigerinu, 61 ; Radiolarian, 87 



Oozooid, 358 



Opalina, 111 ; galvanotaxy, 22 ; ciliiform 

 rtagella, 114 ; species, 124 n. ; nuclei, 



144 n. ; systematic position of, 144 n., 



145 n. ; O. ranantm, 123 

 Opalinidae, 111, 123 f. 

 0])alinopsidae, 145 n. 

 Opercularia, 13S, 158 



Operculum of central capsule of Phaeodaria, 

 76, 82 



Ophiacantha, 492, 4^9 ; moutli-frame, 492 ; 

 0. chelys, 499 



Ophiactis, 49s ; 0. balM, 498 ; virens, 

 491, 498 



Ophiarachna, 481, 499 



Ophicephalous pedicellariae, of Echinus 

 esculentus, 508 ; of E. acutus, 509 ; of 

 E. elegans, 510 ; absent in Cidaridae, 

 534; of Echinarachnius 2M7-ma, 544 



Ophidiaster, 4~1 



Op/iiocoma, 493, 499 ; 0. nigra, 499 



Ophiocomidae, 499 



Opliiodermatidae, 495 n. 



Ophiodes, 277, 2S0 



Ophiogeron, 494 



Ophioglyphu — see Ophiura 



Ojihiohelus, 481, 491, 494 ; 0. mnbella, 

 skeleton, 493 



Ophiolepididae, 495 



Ophiomusium, 497 ; O.pulchellum, 497,498 



Ophiomyxa, 493, 494 t 0. j^enlagona, 494 



Ojihiopholis, 491, 499 ; 0. aculeata, 499 



Ophiopluteus, 606, 608 ; metamorphosis 

 of, 613 



Ophiopsila, 499 



Ophiojjteron, 492, 500 



Ophiopyrgvs, 493, 497 



Ophioscole.r, moutli-fraine. 492 



Ophioteresis, 481, 491, 404 



Oj)lni)thnx, 493, 499 ; mouth-frame, 492 ; 

 0. fragilis (pentaphyUum), 478, 479 : 

 arm of, 479 ; vertebra, 480, 491 ; podia, 

 479 ; mouth-frame, 482 ; disc, 484 ; 

 genital bursa and respiratory movements, 

 485 ; alimentary canal, 485 ; water-vas- 

 cular system, 486 ; axial sinus, 487 ; 

 perihaemal spaces, 488 ; nervous system, 

 488 ; genital organs, 489 



Ophiura (Ophioglyphn), 49n ; 0. albida, 

 497 ; 0. bullata, 495, 496 ; V. ciliaris, 

 485 n., 497 



Ophinroidea (Brittle Stars). 431, 477 t, 

 561 ; mesenchyme of larva, 604 ; de- 

 velopment of, 606, 606, 608, 613 : 

 phylogeny, 622 



O])hli((ispo)igio, 225 



Ophrydiinn, l.iS, 158 



Ophryocystis, 97 



Oplorhiza (Campanulariidae, 2S0), 111 



ih-adis, 377 



Oral apparatus, of Ciliata, its atrophy and 

 regeneration during conjugation, 151 



Oral blood-ring, of Asferias rubens, 450 ; 

 of Ophiothrix fragilis, 488 ; of IIolo- 

 thuria nigra, 567 



Oral cleft or groove of Noctilvca, 132 f. 



Oral coelom of Antedon rosacea, 585 



Oral plates, of Crinoidea, 588; of Thou- 

 matocrinv.s, 589 ; of Jlyocrinus, 588, 

 590 ; of Holopus, b?!^, 592 ; of Rhizo- 

 crinus, 589, 591 ; absent in adult Ante- 

 don, 589 ; of Rhizocrinidae, 590, 591 ; 

 oi Bathycrinus, 591 ; of Cystoidea, 598 ; 

 of Blastoidea, 599 ; of young Antedon 

 rosacea, 619 



Oral spots of Protomastigaceae, 110 



Oral valves, of Antedon rosacea, 581 ; of 

 young A. rosacea, 619 



Orbicella, 373, 375, 4OO 



Orbiculina, 59, 66 



Orbigny, A. d', on Foraminifera, 62 



Orbitoides, 59 



Orbitolites, 59, 66 ; pylomes. 64 ; dimorph- 

 ism, 67 ; monstrous shell, 69 



Orbidi7ia, 59, 66 ; 0. nniversa, 68 



Orbulinella, habitat, 75 



Organ-pipe Coral, 343 



Organella, 44 n. 



Organic compounds, their function in nutri- 

 tion, 35 f. 



Organoid, 44 n. 



Oriental sore, 121 



Ornamentation of shell-wall in Foramini- 

 fera, 66 



OscarcUa. 196, 213. 225; .1. lobidaris. 

 230 



Osculosa (Monotrypasta), 76 



Osculuni, of Radiolaria, 76 ; of Phaeodaria, 

 76, 82 ; of Sponges, 169, 171, 174. 188. 

 189 



Ossicles of Holothuroidea, 569 



Ostium, 169 



Otocvsts, of Elasipoda. 571 ; of Svnaptida, 

 576 



Outer perihaemal ring, of Asterias rubens, 

 448 ; development of, in Asterinagibbosa, 

 612 ; represented by lantern-coelom of 

 Echinus cscidenti's, 52i ; by buccal sinus 

 of Ilolothin-ia nigra, 566 



Ovary of gnat infected by Trypanosoma 

 germs, 120 



Ovoid gland of Ophiothrix fragilis, 489 



Ovum of Sea-urchin, 7 ; of Sarcocystis 

 ienella, 108 n. ; of Volvoxglobator, 127 f. 

 — see also Oosphere. Oosperm, Egg 



Owl, blood parasites of, 120 



Oxea. 183. 224 



