INDEX. 



485 



Median fusion and antero-posterior degeneration, 

 277 



nerve, 43 



Merochord, 328, 330 

 Merostomes, 337 

 Mesencephalon, 18, 19, 65 

 Mesencoele, 66 

 Mesocephalon, 15 

 Mesoderm, 12, 22, 426 



lateral plates of, 231 



sources of, 230 

 Metacephalon, 19 



Metameres, formation of, in limulus, 225 

 Metamerism, 49 

 Metencephalon, 67 

 Middle cord or lemmatochord, 12, 43, 323 



of insects, 324 



of limulus, 334 



of scorpion, 328 



summary or comparison, 335 

 Monstrosities, 274 

 Mouth, 25, 26, 253, 406 



closure of, 18, 31, 249, 251 



Nauplin, 408 



Naupula, 406, 408 



Navel, cephalic, 238, 253, 255, 414 



Neostoma, 26, 238 



Nerves of branchiencephalon, 102 



branchio-thoracic, 105 



cardiac, 200 



circumoral, 42 



cutaneous, 105 



enteric, 103 



gustatory, 84 



haemo-neural, 102 



hypo-branchial, 105, 107 



lateral line, 97 



longitudinal abdominal, 104 



median, 42 



of metencephalon, 98 



neural, 94 



olfactory, 162 



parietal eye, 134 



peripheral, 44, 94 

 arrangement of, 46 

 differentiation of, 45 



of rostrum, 43 



Vagal, 107 

 Nerve ends, in 



roots, 76 



haemal, 77, 81 

 neural, 81 



Nervous system, framework of, 43 

 specialization of, 44; 

 summary of, 209 

 Neural arches, 307, 322 



sinus, 328 



surface, 44 



surfaces, orientation of, 27, 221 

 Neuritemma, 325 

 Neuroblast, 52 



Neuro-coelia, summary of, 92 

 Neuroglia, 93, 325, 331 

 Neuromeres, 49 



branchial, cell clusters of, 73 

 specialization of, 44 



cephalic, 80 



cell clusters of, 80 



components of, 94 



Neuropile, cardiac, 204 



centres, 79 



Neuropore, anterior, 130 

 Neurostoma, 18, 26, 31, 249, 251, 253, 406 

 Notochord, 323 



termination of, 65 



Occipital ring, 316 

 Ocelli, larval, 125, 128 

 Olfactory ganglia, 170 



lobes, 55, 160, 164, 171 



of limulus, 164 

 organ, 127, 160, 162 

 of apus, 167 

 of branchipus, 166 

 of limulus, 1 60 

 of phyllopods, 165 

 nerves, 162 

 placodes, 162, 168 

 Optic ganglia, 13, 62 

 Oral arches, 16, 40, 255 



development of, in frog, 257 

 surface, 44 



Orientation of neural and haemal surfaces, 27, 221 

 Ostracoderms, 337, 341, 348 

 auditory organs, 356 

 cephalic appendages of, 350 

 cutaneous sense organs of, 356 

 eyes of, 355 

 historical review, 342 

 muscle markings in, 346 

 olfactory organs of, 356 

 skeleton of, 351 

 subdivisions of body, 349 

 trend of development in, 341 

 exoskeleton of, 352 



Parietal eye, 13, 125 



ganglion, 142 



nerve, 134 



roots, 134 



Peribranchial chamber, 428 

 Phoroinda, 446, 447 

 Polyzoa, 440 

 Primitive cumulus, 224 



streak, 22, 246 

 Procephalon, 12 

 Procephalic lobes, 13, 38 

 Prosencephalon, 54 

 Psamosteidae, 366 

 Pteraspida, 364, 366 

 Pterobranchia, 439 

 Respiration, 191 

 Rhabdospleura, 440 

 Rostrum, 14, 29 



nerves to, 43 



Saccus vasculosus, 18 

 Segmental sense organs, 17 

 Sense buds, cell division of, 51 



primitive, 50 



organs, 13, no 



auditory, 120 



branchial warts, 115 



general cutaneous, no 



lateral line, 121 



primary, 38 



slime buds, 17, 116 



special cutaneous, in 



summary of, 209 



