INDEX 



Nephrostome, 24, 42, 275, 276 

 Nervous system, of Distomum, 6 



of earthworm, 26 

 of Anodonta, 64 



of gastropods, 77 



of Apus, 104 



of crayfish, 134 



of cockroach, 162 



ofAmphioxus, 1 88 



of dogfish, 234 



of mammals, 297 



Nervures, 154 

 Neural arches, 209 

 Neural crest, 279 

 Neural flexure, 262 

 Neural folds, 256, 257, 301 



groove, 258, 301 



plate, 210, 257 



spines, 210 



tube, 192 



Neurenteric canal, 193, 258 

 Neuroblast, 40 

 Neuropodium, 49 

 Neuropore, 175, 188, 193 

 Notochord, 173, 179, 194, 2OJ., 



209, 2 10, 248, 260, 262, 267, 



281 



Notochordal tissue, 179 

 Notopodium, 49 

 Nuchal groove, 92 

 Nucleus pulposus, 290 

 Nymph, 170 



Oblique muscles of eye, 238, 242 

 Occipital condyles, 211 

 foramen, 153 



nerves, 243 

 Odontophore 69, 76 

 OZsophagus, see Alimentary canal 

 Olfactory capsules, 21 1 



hairs, 136 



lobes, 235, 278 

 nerves, 236 



- organs, 245, 279 



pit, 175 

 Oligochata, 48 

 Omentum, 220 

 Ommatidium, 137 

 Omphaloidean placenta, 304 

 Ontogeny, 282 

 Oostegopod, 98, 106, ill 



Optic capsules, 211 

 chiasma, 236 

 cup, 280 



ganglion, 144 



lobes, 140 



Optic nerve, 236, 280 



vesicles, 280 



Oral tentacles, 177 

 Organs of Bojanus, 64, 73 

 Organ of Corti, 298 

 Ornithorhyncfms, 292, 307 

 Orthoneurous, see Euthyneurous 

 Os articulare, 292 



Os orbiculare, 291 

 Osphradium, 65 

 Otocyst, 65, 80, 87 

 Otolith, 65 

 Ovary, of Distomum, 5 



of earthworm, 33 



of Apus, 106 



of crayfish, 139 



of cockroach, 164 

 ofAmphioxus, 189 



of dogfish, 233 



of mammals, 299 

 Oviducal pores, 20 



funnel, 277 

 Oviduct, of Distomum, 5 

 of earthworm, 33 



of Apus, 1 06 



of crayfish, 140 



of dogfish, 232 



of frog, 277 



of mammals, 298 



Ovisac, 33 . 

 Ovotestis, 80 



Palp, 123, 152 

 Paludina vivipara, 70, 79 

 Pancreas, 219, 264 

 Parachordal plates, 269 

 Paraglossre, 152 

 Parapodia, 48, 49 

 Pareiopods, 117, 144 

 Parenchyma, 6 

 Parovarium, 298 

 Parthenogenesis, 14, 106 

 Pedal ganglia, 64 

 Pelvic girdle, 293 

 Penis, 8 1 

 Pericardial sinus, 1 60, 161 



