748 



INDEX 



Xi'opempheris, 657 



Neopercis, 705 



yeoscopelns, 611 



Neosilurus, 588 



Nephridia, of Amphioxus, 125 



Nephrostomes, 398 ; persistent, 401 



Neplirotome, 397, 398 



Xerophis, 634, 635 



Nerve eminences, 383 



Nervous system, of Chordata, 4 ; of Hemi- 



chordata, 9, 25, 30 ; of Tunicata, 53, 



58, 66 ; of Amphioxus, 127 f., 131 ; of 



Fishes, 367 f. 

 yesiarchus, 679 



Nesting habits of Sticklebacks, 630 

 Nests of Fishes, 414 f., 427, 500, 501, 514, 



515, 517 ; of Arius, 593 ; of Doras and 



Callichthys, 592 ; of Gobius, 690 ; of 

 Gymnarchus, 552 ; of Heterotis, 558 ; of 



Spinachia, 631 

 Nettastoma, 601 

 Nettenchdys, 601 

 Nettophichthys, 601 

 Neural gland, 52 

 Neurenteric canal, 57, 131, 133 

 Neuromeres, 195 n. 

 Neuropore, 10, 58, 59 

 Nilhechte, 550 

 Nilsson, 715 

 Siphon, 659 

 Nisliikawa, 685 n. 

 Noll, 584 n. 



JVomeus, 643 ; Jf. gronovii, 643 

 Norman, 23 

 Notacanthidae, 624 

 Notacanthus, 625 ; N. bonapartii, 625 

 .Ynfof/ogus, 498 

 Notidanidae, 44i 279 ; persistent nephro- 



stomes, 401 

 Notidamis, 44$> 345 ; spiral valve, 267 ; 



^V. cinereus, branchial clefts, 277 ; 



skull, 222 ; N. griseus, branchial clefts, 



277 

 Notochord, 3 ; of Enteropneusta, 14 ; of 



Oephalodiscns, 24, 25 ; of Rhabdopleura, 



'27 ; of Actinotrocha, 28 ; of Tunicata, 



57, 60, 61; of Amphioxus, 119, 118, 



119, 132 ; of Fishes, 193 f. 

 Notoglanidium, 58S 

 Xotoglanis, 588 

 Notogoneus, 572 



Notopteridae, 554, 544, 303, 389, 405 

 Xotopterus, 555, 153, 305, 306 ; N. afer, 



skeleton, 554 ; N. chitala, 555 

 X'otnthenia, 706 

 Nototheniidae, 705, 704 

 Noturus, 588, 590 

 Novacula, 673 



f Nucleus, of Thaliacea, 101, 105 



Nuria, 582 

 Nurse, 97 



Oar-Fish, 715, 163 



Oblata, 664 



Ocelli, 53 



Octacnemidae, 108, 101 



Octacnemus, 109, 101 ; 0. bythius, 109 ; 



0. patagoniensis, 109 

 Odax, 674 

 Odaxothrissa, 563 

 Odontaspis, 4^1 

 Odonteus, 673 

 Odontonectes, 660 

 Odontostomus, 611, 613 

 Oenoscopus, 545 

 Oesophageo-cutaneous duct, 281 

 Oikoplasts, 65 

 Oikopleura, 68, 67, 69 ; transverse section, 



67 ; longitudinal section, 68 ; 0. copho- 



cerca, 66 ; 0. dioica, 70 ; 0. fabelium, 



transverse section, 69 

 Olfactory organs, 155, 390 f., 391, 392 

 Olfactory pit, 129 

 Oligopleuridae, 545, 544 

 Oligopleums, 545 

 Oligorus, 659 

 Oligosarcus, 53 '5 

 Oligotrema, 78, 111 n. 

 Olt, 584 n. 

 Olyra, 588 



Omble Chevalier, 567 

 Omiodon, 611 

 Omosudis, 611 

 Oncorhynchus, 566 

 Oneirodes, 719 ; 0. eschrichtii, 174 

 Onus, 648 ; coloration of larvae, 175 

 Oozooid, 84, 91, 93 

 Opah, 628, 164 



Operculum, 25, 155, 278, 282, 283 

 Opliichthys, 601 

 Ophidiidae, 713, 651, 702, 704, 163, 



361 



Ophidium, 713, 361 ; air-bladder, 302 

 Ophioblennius, 709 

 Ophiocephalidae, 644, 637, 163, 293, 361 ; 



distribution, 645 

 OphiocepJudus, 645 ; labyrinthiform organ, 



293 : 0. marulius, 361 ; 0. gachua, 



361 



Ophiodon, 696 ; 0. elongatus, skull, 692 

 Opisthocentrus, 709 

 Opisthognathus, 661 

 Opisthomi, 716 f., 651, 306 

 Opisthomyzon, 691 

 Opisthonema, 563 

 Opisthoproctus soleatus, telescopic eyes, 



395 



Opisthopteryx, 611 

 Opostomias, 571 ; 0. micripnus, photo- 



phores, 178, 179, 181 

 Opsanus, 711 

 (Jpsariichthys, 582 

 Oral hood, 116, 119, 136 

 Oreinus, 582 



