Ceph"laspis, resem"lance toArthropod,29Ceph"laspis,segmentation,339Ceratodus,148Cephalization,51Cephalodiscus,438Cephalopod,23Cerebellum,47,50Chætopoda,395Chamber, oral, of Ammocœtes,243,287,458Cheliceræ,235Chiasma, optic,101Chilaria,235,238,291,301,458Chitin,85,119,139,205,206,302,329,346,359,440,443Cilia,206Circulation, branchial,174Cirri,357Clarke's column,467Clepsine, nephridial glands,423Cochlea,378Cœlenterata,465,472Cœlolepidæ,344Cœlom,167,251,400,472,481Cœlomata,472Cœlomocœla,472,475Cœlomostomes,477,481Colleneytes,474Commissure, anterior,49Comm"ssure,œsophageal,14Comm"ssure,posterior,48,280Comparison of brains of Ammocœtes and Arthropod,61Comp"rison of br"ins ofinvertebrate from Branchipus to Ammocœtes,54Comp"rison of br"ins ofvertebrate,40Comp"rison ofbranchial circulation in Ammocœtes and Limulus,174Comp"rison of bran"hiallamellæ of Scorpion and Ammocœtes,175Comp"rison of bran"hialsegments of Ammocœtes and Petromyzon,169Comp"rison ofCephalaspidian and Palæostracan fish,31Comp"rison ofCœlom of Peripatus and Vertebrate,400Comp"rison ofdermal covering of Pteraspis with chitin of Limulus or dentine of fish scales,346Comp"rison ofentosternite or plastron of Limulus with trabeculæ of Ammocœtes,145Comp"rison ofexcretory organs of vertebrates and invertebrates,389Comp"rison ofgut of Arthropod and tube of central nervous system of Vertebrate,43,244,433,440,455,457Comp"rison ofhead-shield of Cephalaspis and Ammocœtes,291,329,338Comp"rison ofhypophysial tube with olfactory tube of Arthropod ancestor,229Comp"rison of hypop"ysial t"bewith position of palæostoma,317Comp"rison ofmesosomatic region of Ammocœtes and Eurypterus,192Comp"rison ofmuscles, branchial, of Ammocœtes and appendage muscles of Scorpion,171,447Comp"rison of mu"cles,eye, of Vertebrate with dorso-ventral muscles of Scorpion,267,272,459Comp"rison of mu"cles,of oral chamber of Ammocœtes and prosomatic musculature of Limulus,247,447Comp"rison of mu"cles,longitudinal body-muscles of Vertebrate and dorsal longitudinal muscles of Arthropod,411,447Comp"rison ofnerves, appendage of Limulus and Branchipus to lateral root system of Vertebrate,157Comp"rison of ne"ves,cranial and spinal segmental,152Comp"rison ofnervous systems of Vertebrate and Arthropod,36Comp"rison ofpineal gland of vertebrates and median eyes of Arthropod,63,456Comp"rison ofpituitary body and coxal glands,246,319,321Comp"rison ofprosoma and mesosoma of Limulus and Ammocœtes,140,141Comp"rison ofprosomatic region of Ammocœtes and Eurypterus,244,333Comp"rison ofretina in Ammocœtes and Musca,97Comp"rison of re"inacompound in Arthropod and Vertebrate,87Comp"rison ofskeleton of Limulus and Ammocœtes,126,136Comp"rison ofsense-organs of Arthropod appendages with auditory organs of Vertebrate,375Comp"rison ofthyroid with endostyle,198Comp"rison of thy"oid w"thuterus of Scorpion,205Corneagen,69Corpora quadrigemina,47Corpuscles, Pacinian, Herbst, Grandry, etc.,470Coxal glands,242,246,319,321,389,398,403,429Cranium,121,145,339Crayfish,442,489Crest, neural,281Cromatophores of frog,470Crura cerebri,14Crustacea, first appearance,27Crust"cea,eyes,76,87Crust"cea,retina,100Crust"cea,segmental glands,422Ctenophora,474Cyathaspis,29,326,340,343Cyclostomata,165,229,343,353,424Cysts,50Daphnia,112Degeneration,17,19,59,74,78,94,107,212,309,333,336,343Deiters' nucleus,489Dendrites,72Development, parallel,497Devel"pment,of two types of eye,73Devel"pment,vertebrate retina,101Diaphragms,161,167Didymaspis,327,338Digestion,441Dinosaurs,17Dipnoans,23,45,148Diptera,89,369Diverticula, optic,102Dogfish, skull,121,123Drepanaspis,344,345,450Drepanopterus Bembycoides,238Ectognath,238,242,271,304,342,381Eel,488Elasmobranchs,23,343,423Elastin,435Embryo, head of dogfish,121,123Em"ryo,skull of pig,121Embryology, principles of,455Encepalomeres,262Endognath,238,271,304,381Endostoma,241,306Endostyle,198,212Entapophysis of Limulus,139Enterocœla,472Enteropneusta,438,494Entochondrites,377Entosclerite,222,271Entosternite,143Epiblast,444,445,459Epithelium cells of Ammocœtes,347Epith"liumof central nervous system of vertebrates,38,457Epith"lium ofcœlomic spaces in annelids,421Epith"lium ofoptic diverticula,103Epith"lium ofperitoneal, pleural, and pericardial cavities,477Epith"lium ofvelum of Ammocœtes,301,302Equilibration,358Eukeraspis,326Eurypterus,26,150,191,237Eury"terus,appendages,150,236,237Eury"terus,classification,249Eury"terus,comparison with Ammocœtes,170,323Eury"terus,diagram of sagittal median section,240,245Eury"terus,endostoma,241,306Eury"terus,eyes,275Eury"terus,mesosomatic segments,192Eury"terus,muscles of carapace,269Eury"terus,operculum,150,190,212Evidence of alimentary canal, innervation,446Evide"ce ofauditory apparatus and lateral line organs,355Evide"ce ofcœlomic cavities in Limulus,251Evide"ce ofdegeneracy in Ammocœtes,59,94,343Evide"ce ofembryology, cartilage,20,129Evide"ce of embry"logy,eye-muscles,263Evide"ce of embry"logy,excretory organs,390Evide"ce of embry"logy,heart,179,451Evide"ce of embry"logy,nervous system, central, cerebral vesicles,48,458Evide"ce of embry"logy, ner"ous sy"tem, ce"tral,epithelial tube,37,42,102,244,433,455Evide"ce of embry"logy, ner"ous sy"tem, ce"tral,neurenteric canal,37Evide"ce of embry"logy, ner"ous sy"tem, ce"tral,neuropore,220,457Evide"ce of embry"logy, ner"ous sy"tem, ce"tral,optic diverticula,102Evide"ce of embry"logy, ner"ous sy"tem, ce"tral,spinal cord,46Evide"ce of embry"logy,oral chamber,228,242,243,290Evide"ce of embry"logy,olfactory organ,220,227Evide"ce of embry"logy,palæostoma or old mouth,317Evide"ce of embry"logy,pineal or median eyes,15,63,74,456Evide"ce of embry"logy,pituitary body and coxal glands,246,319Evide"ce of embry"logy,thyroid,192,194Evide"ce of embry"logy,segmentation, double, of head,157,234,258Evide"ce of embry"logy,skeleton, cranial,120,153Evide"ce ofnervous system, central,8Evide"ce ofnotochord, origin from segmented region,443Evide"ce ofolfactory apparatus,218Evide"ce oforgans of vision,68Evide"ce ofpalæontology,20,497Evide"ce ofpineal or median eyes,74Evide"ce ofprosomatic musculature,247Evide"ce ofrespiratory apparatus,148Evide"ce ofsegmentation in head-shield,339Evide"ce ofskeleton,119Evolution,8,15,20,149,482,497Evol"tion,of brain in brain-case,210Evol"tion, ofcranium of Vertebrate,342Evol"tion, ofexcretory organs,389Evol"tion, ofeye of Vertebrate,114Evol"tion, ofnervous system, central,34Evol"tion, oftissues,19Evol"tion, ofVertebrate from Balanoglossus and Amphioxus,33Eyes,68Ey"s,lateral,87,105,108Ey"s,median or pineal,74,77,78,79Fat-cells in muco-cartilage,332Fat-column of Ammocœtes,181,182Fibres, Mauthnerian,488Fib"rs,Müllerian, of Ammocœtes central nervous system,489Fib"rs, Müll"rian, ofretina,96,107Fishes, classification,218Fis"es,ancient, classification,326,343Fis"es, ani"ent,cloacal region,450Fis"es, ani"ent,dominance,23Fis"es, ani"ent,eyes,75Fis"es, ani"ent,head-shields.SeeHead-shieldsFis"es, ani"ent,pleural folds,414Fissure, posterior,43Fittest, survival of,16,34Flabellum,359,360,362,363,366Folds, pleural,410,414Function of auditory organ, double,358Funt"ion oflateral line sense-organs,357Funt"ion ofnerves,448Funt"ion ofthyroid,212,215Fusion of ganglia,52Galeodes,230Gale"des,brain, and camerostome,222,223Gale"des,primordial cranium,341Gale"des,racquet-organs,369,375Ganglia, infraœsophageal,4,12,14,51,221Ganl"ia,supraœsophageal,4,12,14,49,52,221,225Ganl"ia,origin of, of cranial and spinal nerves,281Ganglion, epibranchial,164,282Ganl"ion,habenulæ,48,78Ganl"ion,optic of retina,72,89,97Ganl"ion,of posterior root,466Ganl"ion,cells of sympathetic system,424,428,448Ganoids,23,345Gastrula theory,165,459Genital corpuscles,470Geological record,20Geol"gicalstrata,22Geotria australis,80Germ-band,482Germ-cells,471Giant-fibres,489Gigantostraca,25,234Gills,148,161,185,214,494Glabellum,339Glands, carotid,427Gla"ds,coxal,242,246,319,321,425,429Gla"ds,ductless,418Gla"ds,generative, of Limulus,209Gla"ds,internal secretion of,214Gla"ds,lymphatic,418Gla"ds,pineal,15,63,75,456Gla"ds,pituitary,244,246,319,425Gla"ds,segmental, of Crustacea,422Gla"ds,submaxillary,466Gla"ds,sweat,448Gla"ds,thymus,425Gla"ds,thyroid, of Ammocœtes,193,194,196,201,205,429Gla"ds,tissue round brain of Ammocœtes,209,379Gla"ds,uterine, of Scorpion,202,203,204,205Gnathostomata,60,343Goblet,359,360,373Goitre,215Gonad,475,479Gonocœle,475,481Grooves, ciliated,188,197,212Gro"ves,hyper-pharyngeal of Amphioxus,410Gro"ves,ventral, of apus and trilobites,436Gymnophiona,393Hæmocytes,472Head of embryo dogfish,121,123Head-shield, dorsal, of Ammocœtes,330,331,338Head-s"ield, dor"al, ofAuchenaspis,29,31,338Head-s"ield, dor"al, ofCephalaspis,327,328,330,338,348Head-s"ield, dor"al, ofCyathaspis,340Head-s"ield, dor"al, ofDidymaspis,338Head-s"ield, dor"al, ofevidence of segmentation,339Head-s"ield, dor"al, ofKeraspis,328
Ceph"laspis, resem"lance toArthropod,29
Ceph"laspis,segmentation,339
Ceratodus,148
Cephalization,51
Cephalodiscus,438
Cephalopod,23
Cerebellum,47,50
Chætopoda,395
Chamber, oral, of Ammocœtes,243,287,458
Cheliceræ,235
Chiasma, optic,101
Chilaria,235,238,291,301,458
Chitin,85,119,139,205,206,302,329,346,359,440,443
Cilia,206
Circulation, branchial,174
Cirri,357
Clarke's column,467
Clepsine, nephridial glands,423
Cochlea,378
Cœlenterata,465,472
Cœlolepidæ,344
Cœlom,167,251,400,472,481
Cœlomata,472
Cœlomocœla,472,475
Cœlomostomes,477,481
Colleneytes,474
Commissure, anterior,49
Comm"ssure,œsophageal,14
Comm"ssure,posterior,48,280
Comparison of brains of Ammocœtes and Arthropod,61
Comp"rison of br"ins ofinvertebrate from Branchipus to Ammocœtes,54
Comp"rison of br"ins ofvertebrate,40
Comp"rison ofbranchial circulation in Ammocœtes and Limulus,174
Comp"rison of bran"hiallamellæ of Scorpion and Ammocœtes,175
Comp"rison of bran"hialsegments of Ammocœtes and Petromyzon,169
Comp"rison ofCephalaspidian and Palæostracan fish,31
Comp"rison ofCœlom of Peripatus and Vertebrate,400
Comp"rison ofdermal covering of Pteraspis with chitin of Limulus or dentine of fish scales,346
Comp"rison ofentosternite or plastron of Limulus with trabeculæ of Ammocœtes,145
Comp"rison ofexcretory organs of vertebrates and invertebrates,389
Comp"rison ofgut of Arthropod and tube of central nervous system of Vertebrate,43,244,433,440,455,457
Comp"rison ofhead-shield of Cephalaspis and Ammocœtes,291,329,338
Comp"rison ofhypophysial tube with olfactory tube of Arthropod ancestor,229
Comp"rison of hypop"ysial t"bewith position of palæostoma,317
Comp"rison ofmesosomatic region of Ammocœtes and Eurypterus,192
Comp"rison ofmuscles, branchial, of Ammocœtes and appendage muscles of Scorpion,171,447
Comp"rison of mu"cles,eye, of Vertebrate with dorso-ventral muscles of Scorpion,267,272,459
Comp"rison of mu"cles,of oral chamber of Ammocœtes and prosomatic musculature of Limulus,247,447
Comp"rison of mu"cles,longitudinal body-muscles of Vertebrate and dorsal longitudinal muscles of Arthropod,411,447
Comp"rison ofnerves, appendage of Limulus and Branchipus to lateral root system of Vertebrate,157
Comp"rison of ne"ves,cranial and spinal segmental,152
Comp"rison ofnervous systems of Vertebrate and Arthropod,36
Comp"rison ofpineal gland of vertebrates and median eyes of Arthropod,63,456
Comp"rison ofpituitary body and coxal glands,246,319,321
Comp"rison ofprosoma and mesosoma of Limulus and Ammocœtes,140,141
Comp"rison ofprosomatic region of Ammocœtes and Eurypterus,244,333
Comp"rison ofretina in Ammocœtes and Musca,97
Comp"rison of re"inacompound in Arthropod and Vertebrate,87
Comp"rison ofskeleton of Limulus and Ammocœtes,126,136
Comp"rison ofsense-organs of Arthropod appendages with auditory organs of Vertebrate,375
Comp"rison ofthyroid with endostyle,198
Comp"rison of thy"oid w"thuterus of Scorpion,205
Corneagen,69
Corpora quadrigemina,47
Corpuscles, Pacinian, Herbst, Grandry, etc.,470
Coxal glands,242,246,319,321,389,398,403,429
Cranium,121,145,339
Crayfish,442,489
Crest, neural,281
Cromatophores of frog,470
Crura cerebri,14
Crustacea, first appearance,27
Crust"cea,eyes,76,87
Crust"cea,retina,100
Crust"cea,segmental glands,422
Ctenophora,474
Cyathaspis,29,326,340,343
Cyclostomata,165,229,343,353,424
Cysts,50
Daphnia,112
Degeneration,17,19,59,74,78,94,107,212,309,333,336,343
Deiters' nucleus,489
Dendrites,72
Development, parallel,497
Devel"pment,of two types of eye,73
Devel"pment,vertebrate retina,101
Diaphragms,161,167
Didymaspis,327,338
Digestion,441
Dinosaurs,17
Dipnoans,23,45,148
Diptera,89,369
Diverticula, optic,102
Dogfish, skull,121,123
Drepanaspis,344,345,450
Drepanopterus Bembycoides,238
Ectognath,238,242,271,304,342,381
Eel,488
Elasmobranchs,23,343,423
Elastin,435
Embryo, head of dogfish,121,123
Em"ryo,skull of pig,121
Embryology, principles of,455
Encepalomeres,262
Endognath,238,271,304,381
Endostoma,241,306
Endostyle,198,212
Entapophysis of Limulus,139
Enterocœla,472
Enteropneusta,438,494
Entochondrites,377
Entosclerite,222,271
Entosternite,143
Epiblast,444,445,459
Epithelium cells of Ammocœtes,347
Epith"liumof central nervous system of vertebrates,38,457
Epith"lium ofcœlomic spaces in annelids,421
Epith"lium ofoptic diverticula,103
Epith"lium ofperitoneal, pleural, and pericardial cavities,477
Epith"lium ofvelum of Ammocœtes,301,302
Equilibration,358
Eukeraspis,326
Eurypterus,26,150,191,237
Eury"terus,appendages,150,236,237
Eury"terus,classification,249
Eury"terus,comparison with Ammocœtes,170,323
Eury"terus,diagram of sagittal median section,240,245
Eury"terus,endostoma,241,306
Eury"terus,eyes,275
Eury"terus,mesosomatic segments,192
Eury"terus,muscles of carapace,269
Eury"terus,operculum,150,190,212
Evidence of alimentary canal, innervation,446
Evide"ce ofauditory apparatus and lateral line organs,355
Evide"ce ofcœlomic cavities in Limulus,251
Evide"ce ofdegeneracy in Ammocœtes,59,94,343
Evide"ce ofembryology, cartilage,20,129
Evide"ce of embry"logy,eye-muscles,263
Evide"ce of embry"logy,excretory organs,390
Evide"ce of embry"logy,heart,179,451
Evide"ce of embry"logy,nervous system, central, cerebral vesicles,48,458
Evide"ce of embry"logy, ner"ous sy"tem, ce"tral,epithelial tube,37,42,102,244,433,455
Evide"ce of embry"logy, ner"ous sy"tem, ce"tral,neurenteric canal,37
Evide"ce of embry"logy, ner"ous sy"tem, ce"tral,neuropore,220,457
Evide"ce of embry"logy, ner"ous sy"tem, ce"tral,optic diverticula,102
Evide"ce of embry"logy, ner"ous sy"tem, ce"tral,spinal cord,46
Evide"ce of embry"logy,oral chamber,228,242,243,290
Evide"ce of embry"logy,olfactory organ,220,227
Evide"ce of embry"logy,palæostoma or old mouth,317
Evide"ce of embry"logy,pineal or median eyes,15,63,74,456
Evide"ce of embry"logy,pituitary body and coxal glands,246,319
Evide"ce of embry"logy,thyroid,192,194
Evide"ce of embry"logy,segmentation, double, of head,157,234,258
Evide"ce of embry"logy,skeleton, cranial,120,153
Evide"ce ofnervous system, central,8
Evide"ce ofnotochord, origin from segmented region,443
Evide"ce ofolfactory apparatus,218
Evide"ce oforgans of vision,68
Evide"ce ofpalæontology,20,497
Evide"ce ofpineal or median eyes,74
Evide"ce ofprosomatic musculature,247
Evide"ce ofrespiratory apparatus,148
Evide"ce ofsegmentation in head-shield,339
Evide"ce ofskeleton,119
Evolution,8,15,20,149,482,497
Evol"tion,of brain in brain-case,210
Evol"tion, ofcranium of Vertebrate,342
Evol"tion, ofexcretory organs,389
Evol"tion, ofeye of Vertebrate,114
Evol"tion, ofnervous system, central,34
Evol"tion, oftissues,19
Evol"tion, ofVertebrate from Balanoglossus and Amphioxus,33
Eyes,68
Ey"s,lateral,87,105,108
Ey"s,median or pineal,74,77,78,79
Fat-cells in muco-cartilage,332
Fat-column of Ammocœtes,181,182
Fibres, Mauthnerian,488
Fib"rs,Müllerian, of Ammocœtes central nervous system,489
Fib"rs, Müll"rian, ofretina,96,107
Fishes, classification,218
Fis"es,ancient, classification,326,343
Fis"es, ani"ent,cloacal region,450
Fis"es, ani"ent,dominance,23
Fis"es, ani"ent,eyes,75
Fis"es, ani"ent,head-shields.SeeHead-shields
Fis"es, ani"ent,pleural folds,414
Fissure, posterior,43
Fittest, survival of,16,34
Flabellum,359,360,362,363,366
Folds, pleural,410,414
Function of auditory organ, double,358
Funt"ion oflateral line sense-organs,357
Funt"ion ofnerves,448
Funt"ion ofthyroid,212,215
Fusion of ganglia,52
Galeodes,230
Gale"des,brain, and camerostome,222,223
Gale"des,primordial cranium,341
Gale"des,racquet-organs,369,375
Ganglia, infraœsophageal,4,12,14,51,221
Ganl"ia,supraœsophageal,4,12,14,49,52,221,225
Ganl"ia,origin of, of cranial and spinal nerves,281
Ganglion, epibranchial,164,282
Ganl"ion,habenulæ,48,78
Ganl"ion,optic of retina,72,89,97
Ganl"ion,of posterior root,466
Ganl"ion,cells of sympathetic system,424,428,448
Ganoids,23,345
Gastrula theory,165,459
Genital corpuscles,470
Geological record,20
Geol"gicalstrata,22
Geotria australis,80
Germ-band,482
Germ-cells,471
Giant-fibres,489
Gigantostraca,25,234
Gills,148,161,185,214,494
Glabellum,339
Glands, carotid,427
Gla"ds,coxal,242,246,319,321,425,429
Gla"ds,ductless,418
Gla"ds,generative, of Limulus,209
Gla"ds,internal secretion of,214
Gla"ds,lymphatic,418
Gla"ds,pineal,15,63,75,456
Gla"ds,pituitary,244,246,319,425
Gla"ds,segmental, of Crustacea,422
Gla"ds,submaxillary,466
Gla"ds,sweat,448
Gla"ds,thymus,425
Gla"ds,thyroid, of Ammocœtes,193,194,196,201,205,429
Gla"ds,tissue round brain of Ammocœtes,209,379
Gla"ds,uterine, of Scorpion,202,203,204,205
Gnathostomata,60,343
Goblet,359,360,373
Goitre,215
Gonad,475,479
Gonocœle,475,481
Grooves, ciliated,188,197,212
Gro"ves,hyper-pharyngeal of Amphioxus,410
Gro"ves,ventral, of apus and trilobites,436
Gymnophiona,393
Hæmocytes,472
Head of embryo dogfish,121,123
Head-shield, dorsal, of Ammocœtes,330,331,338
Head-s"ield, dor"al, ofAuchenaspis,29,31,338
Head-s"ield, dor"al, ofCephalaspis,327,328,330,338,348
Head-s"ield, dor"al, ofCyathaspis,340
Head-s"ield, dor"al, ofDidymaspis,338
Head-s"ield, dor"al, ofevidence of segmentation,339
Head-s"ield, dor"al, ofKeraspis,328