Head-s"ield, dor"al, of Ostreostraci, 327, 348
Head-s"ield, dor"al, of Palæostracan, 348
Head-s"ield, dor"al, of Pteraspis, 29
Head-s"ield, dor"al, of Thyestes, 29, 31, 327, 332, 338, 340, 341, 348
Head-s"ield, ventral, Scaphaspis, 349
Her"t, origin of vertebrate, 179, 451, 459
Her"t, relative position in vertebrate and invertebrate, 175
Her"t, veins forming vertebrate, 180
Hemiaspis, 24, 25, 249, 250, 351, 414
Hemispheres, cerebral, 47
Hepatopancreas of Ammocœtes, 452
Hepatop"ncreas of Limulus, 211
Heterostraci, 29, 275, 326, 343
Hirudinea, 478
Histolysis in transformation of the lamprey, 59
Homology of branchial region of vertebrate and invertebrate, 149
Homol"gy of ductless glands and nephridial organs, 418
Homol"gy of external genital ducts of arthropods and nephridia of annelids, 429
Homol"gy of germinal layers in all Metazoa, 459
Homol"gy of pituitary body of Ammocœtes and coxal glands of Limulus, 319
Homol"gy of tubular muscles of Ammocœtes and veno-pericardial muscles of Limulus, 309
Homol"gy of ventral aorta of vertebrate and longitudinal venous sinuses of Limulus, 178
Hydrophilus larva, eye, 84
Hyoid segment in Ammocœtes, 186, 267
Hypoblast, 434, 438, 444, 445, 459
Hypoctonus, cartilage cells in entosternite, 133
Hypo"tonus, operculum, 189, 207
Hypogastric plexus, 3
Hypogeophis, 393
Hypophysis, 229, 244, 317, 318, 340
Infundibulum, position, 122,132
Infun"ibulum, tube, the ancestral œsophagus, 4, 37, 244, 318
Infun"ibulum, tu"e, relation to neural canal, 14, 36, 318, 440, 457
Infun"ibulum, tu"e, relati"n to notochord, 318, 435,440
Infun"ibulum, tu"e, relati"n to olfactory tube, 220, 228, 318, 340
Insects, chordotonal organs, 364, 370
Invert"brate, excretory organs, 418
Invert"brate, nervous system, 13, 54
Invert"brate, segmental nerves, 152
Kid"ey, nerves, 477
King-crab, v. Limulus
Lamina terminalis, 49
Lamprey, v. Ammocœtes and Petromyzon
Larva, v. Transformation of the Lamprey
Lateral line system, 261, 355, 411, 470
Law of Progress, 19
Lw" of Recapitulation, 434, 456, 498
Layer, germinal, 459
Leech, 421
Limulus or king-crab, 25, 140, 236, 240
Liml"us appendages, branchial, 138, 164, 175
Liml"us appendages, prosomatic, 381
Liml"us brain, 54
Liml"us classification, 26, 249
Liml"us cœlomic cavities, 252, 328
Liml"us coxal glands, 321, 389, 397, 403, 429
Liml"us eyes, median, 62, 74, 81
Liml"us entosternite or plastron, 142, 143
Liml"us flabellum, 360, 362, 363, 380, 381
Liml"us generative organs and ducts, 189, 202, 208, 209, 380
Liml"us heart, 180
Liml"us musculature, branchial, 170
Liml"us muscl"ature, prosomatic, 247
Liml"us muscl"ature, veno-pericardial, 177, 297, 309, 313
Liml"us nerves, appendage, 140, 157
Liml"us ner"es, cardiac, 314
Liml"us ner"es, segmental, tripartite division of, 157, 235, 267, 355
Liml"us segments, branchial, 152
Liml"us segm"nts, first mesosomatic, 188
Liml"us segm"nts, prosomatic, 233
Liml"us operculum, 189, 202, 235, 295
Liml"us sense-organs, poriferous, of appendages, 359
Lip, lower, of Ammocœtes, 246, 289, 297, 458
Li", upper, of Am"ocœtes, 228, 243, 303, 336
Liver, Ammocœtes, 452
Lizard, pineal eye, 80
Liz"rd, suprarenals, 424
Liz"rd, tail, 50
Lobes, optic, 101
Lobster, 489
Lungs, 148
Lung-books of scorpions, 150
Lymph, 474
Lymphocytes, 472
Malapterurus, 470
Mammal, dominance of, 21
Man, dominance of, 17
Medullation of nerve-fibres, 20, 267, 467, 477
Membranes, basement, 436
Meroblastic egg, 485
Mesencepalon, 48
Mesoglœa, 474
Mesonephros, 389, 400, 424, 429
Mesosoma, 52
Metanephros, 389
Metastoma, 239, 246, 272, 289, 342, 458
Mollusca, dominance of, 23
Mouth, old, or palæostoma, 14, 317, 322, 440, 458
Mo"th, vertebrate, 317
Muco-cartilage, v. Cartilage
Muscles, antagonistic, 447
Mus"les, branchial, 170
Mus"les, connection of, with central nervous system, 464
Mus"les, eye, and their nerves, 263
Mus"les, phylogeny of origin of skeletal, 478
Mus"les, rudimentary, in Ammocœtes, 289
Mus"les, somatic trunk, origin of, 406
Mus"les, tubular, of Ammocœtes, 309
Mus"les, unstriped, 20, 447, 491
Mus"les, visceral and parietal, 155, 172
Mus"les, veno-pericardial of Limulus and Scorpion, 177, 297, 309
Muscle-spindles, 267
Mygalidæ, stomach, 109
Mygl"idæ, segmentation, 249, 306
Myotomes, 332, 337, 338, 391, 407, 408
Mysis, eyes, 100
My"is, ductless glands, 422
Nemertina, 475
Nephrocœle, 430
Nephrotome, 393
Nerves, abducens, 155, 263, 266
Ner"es, autonomic, 3
Ner"es, facial, 155, 156, 186, 188, 192, 311, 356, 378
Ner"es, fa"ial, ramus branchialis profundus, 311
Ner"es, to flabellum, in Limulus, 361, 375
Ner"es, glossopharyngeal, 155, 156, 186, 356
Ner"es, hypoglossal, 156
Ner"es, inhibitory, 447
Ner"es, inedullation of, 20, 267, 467, 477
Ner"es, occulomotor, 155, 234, 263, 274
Ner"es, olfactory, 229
Ner"es, ot"ic, of pineal eye, 79
Ner"es, origin of ganglia of cranial and spinal, 281
Ner"es, to pecten of Scorpion, 375, 376
Ner"es, preganglionic, 2
Ner"es, of prosoma in Limulus, 235, 355
Ner"es, regeneration of, 469
Ner"es, roots, of Limulus, 157
Ner"es, sacral, 448
Ner"es, segmental nature of cranial, 259, 411
Ner"es, spinal, absence of lateral roots in, 388
Ner"es, spinal accessory, 154
Ner"es, trigeminal, 151, 155, 156, 234, 243, 257, 279
Ner"es, trigm"inal, motor nucleus of, 280
Ner"es, trigm"inal, of Ammocœtes, 288
Ner"es, tripartite arrangement of cranial nerves, 154, 157, 235, 267, 355
Ner"es, trochlear, 48, 155, 234, 263, 276
Ner"es, vagus, 151, 154, 156, 173, 186, 356, 447, 449
Nervous system, central, comparison of Vertebrate and Arthropod, 36, 457
Nervous "ystem, ce"tral, connection of, with muscular and epithelial tissues, 464
Nervous "ystem, ce"tral, conne"tion of, with retina, 71
Nervous "ystem, ce"tral, disease of, 50
Nervous "ystem, ce"tral, evidence of, 8
Nervous "ystem, ce"tral, evolution of, 34
Nervous "ystem, ce"tral, importance of, 16, 463, 482, 498
Nervous "ystem, ce"tral, invertebrate, 10, 13, 54
Nervous "ystem, ce"tral, origin of, 480
Nervous "ystem, ce"tral, relation of germ-band to, 483
Nervous "ystem, ce"tral, segmentation of vertebrate, 51
Nervous "ystem, ce"tral, tube of, 36-51, 102, 211, 433, 455, 457
Nervous "ystem, ce"tral, vertebrate, 10, 13, 40, 41, 152
Nervous "ystem, enteric, 447
Nervous "ystem, sympathetic, 2, 424, 428, 448, 491
Neurenteric canal, 37
Neuroblast, 465
Neuromeres, 55, 247, 262, 312, 316
Nose, 219
No"e, of Osteostraci, 329, 352, 458
Notochord, 120, 122, 180, 181, 220, 244, 295, 318, 405, 417, 433, 436, 494
Ocelli, 70
Œsophagus of Ammocœtes, 405
Œsop"agus of Arthropod, compared to tube of infundibulum, 4, 244, 440
Olfactory apparatus, evidence of the, 218
Olfa"tory organs of the Scorpion group, 220
Olfa"tory tube of Ammocœtes, 219, 225, 244, 317
Operculum of Eurypterus, 191, 212, 291
Operc"lum of Limulus, 189, 202, 235, 295
Operc"lum of Phrynus, 191
Operc"lum of Scorpion, 189, 206, 212, 372
Operc"lum of Thelyphonus, 189, 190, 206
Organs, arrangement of, 10
Org"ns, auditory, of arachnids and Insects, 368
Org"ns, branchial, innervation of vertebrate, 151
Org"ns, bran"hial, sense-organs of embryo vertebrate, 261, 281
Org"ns, chordotonal, of insects, 364, 369, 370
Org"ns, electric, 470
Org"ns, generative, of Limulus, 208, 209
Org"ns, gener"tive, connection between Thyroid gland and, 215
Org"ns, genital, of sea-scorpions, 206
Org"ns, lateral line, 355, 411
Org"ns, lyriform, of arachnids, 364, 369
Org"ns, olfactory, of Scorpion group, 220
Org"ns, phagocytic, 420
Org"ns, racquet, of Galeodes, 369, 375
Org"ns, segmental excretory, 389, 391, 408, 418, 459, 477
Org"ns, sense, of appendages of Limulus, 358
Org"ns, vestigial, 456
Org"ns, of vision, evidence of, 68