INDEX 



Reproduction, 139: Development, 139 : 

 Systematic position, 142 

 Occlusor muscle, 350 

 Ocelli, 143, 173 



Octopoda, 680, 790*, 791, 793, 797, 804 

 Octopus, 791, 793, 796 

 Octorchandra, 150 

 Ocular plates, 396, 397 

 Odentophora, 676*, 678 

 Odontophore, 721, 726, 727 

 (Esophagus See Digestive system 

 Oikomonas, 71, 72 

 Olfactory organs, 39* : pits, 173* 

 Oligochseta, 465*, 468, 469, 471, 473, 474, 

 475, 478, 479, 481, 482, 483, 486, 488, 

 489 



Olynthu*, 116 

 Ommatidium, 536*, 537 

 Onchidium, 746 

 Omscus, 568, 583, 587 

 Onychophora, 526, 607*, 677, 678 -See 



Peripatus 

 Orecium, 341 

 Ookinete, 87* 

 Oosperm, 21* 

 Oostegites, 585* 

 Oostegopod, 531* 

 Ootype, 243, 270, 271 

 Opalina, 93, 98, 99 

 Opalinopsis, 94 

 Opercuhim Radiolaria, 61, 62: Ciliata, 



95, 96 : Gastropoda, 723*, 724, 739 

 Ophioglypha, 420 



Ophiuroidea, Distinctive characters and 

 classification, 411* : General form and 

 symmetrv, 415 : Sj'stem of plates, 

 418 : Modifications of form, 420, 421 : 

 Ccelome, 425 : Ambulacral system, 

 426; Blood- vascular system, 426: 

 Ha?mal system, 427 : Axial organ, 

 428 : Enteric canal, 428 : Nervous 

 system, 429 : Reproductive organs, 

 429 : Development, 430 : Ethology, 

 &c., 434 



Ophrydium, 95, 97 

 Ophryodenclron, 100 

 Ophryoylena, 94 

 Opisthobranchia, 734*, 738, 744, 745' 



755 



Opisthogoneata, 615*, 619, 677 

 Opisthorchis sinensis, 285 

 Opossum-Shrimp, 523 

 Optic gland, 772 

 Optic vesicle, 802 

 Oral, 376* : Arms, 170* 

 Orchestia, 583, 594 

 Order, 4* 



Organ of Bojanus, 689* : cf. Owen, 780* 

 Organic evolution See Evolution 

 Organism, 1* 

 Organ-pipe Coral, 195 

 Organs, 31* 

 Oriental region, 9* 



VOL. I. 



Orobdella, 516 



Orthoc.erax, 803 



OrthonectidcK, 230, 232, 233, 234 



Orthoptera, 632*, 638, 640, 653 



Othoptera genuina, 636 



Oxcardla, 117 



Owaria, 115 



Oscular sphincter, 111* 



Osculum, 106" 



Osphradium, 691, 707, 731, 797 



Ossicles, 375 



Ostia, 106*, 109, 533* 



Ostium, 187* 



Ostracoda, 564*, 572, 573, 593, 594, 597, 



598, 601, 602 



Offtrea, 696, 698, 701. 706, 708, 709 

 Otocyst, 39*, 478 

 Ovariole, 628*, 646 

 Ovary, 39* 

 Ovicells, 352 

 Oviduct, 40* 

 Oviparous, 40* 

 Ovipositor, 610 

 Ovum, 19*, 30 

 Owen, organ of, 780 

 Oxygen, oxidation, 36 

 Oxeole spicules, 108, 110* 

 Oxywis, 307 

 Oysters, 680, 696 



ACHYCHALINA, 121 

 Pasdogenesis, 41*, 224*, 647 

 Pagurus, 569, 589 

 Palcemon, 569, 588 

 Paht'monetes, 593 

 Palasarctic region, 9* 

 Palaeodictyoptera, 652 

 Paheontologv, 6* 

 Palinurn*, 569, 587, 595, 599, 602 

 Pallial line, 683* 

 Pallial gi-oove, 344 

 Pallial sinus, 365 

 Pallial muscles, 684 

 Pallial complex, 735 

 Pallium Sec Mantle 

 Palpus, 470 

 Palml'in-lla, 348, 353 

 Pulndiii'i, 754 

 Palus, 205* 

 Palythoa, 127, l!>7 

 Pancreas, 34* 

 Pancreatic juice, 34* 

 Prtudorinri, 72, 73, 74, 75 

 Papula, 424* 



Parapodium, 439, 440, 441, 468, 739 

 Paragastric cavity, 106*, 108 

 Paragnatha, 530*, 548 



/'it /'(/tin rif/ii , 91 



PARAMOSCIUM, 88, 89, 90 : Systematic 

 position, 91 



3 G 



