INDEX. 



685 



My gale, 453 

 Mygalidae, 453 

 Mygnimia, 49 

 Myidae, 368 

 Mylodon, 636 

 Myocommata, 531 

 Myomerism, 523 

 Myomorpha, 639 

 Myopsida, 395 

 Myosepta, 531 

 Myotomes, 531 

 Myrianida, 310, 313 

 Myriapotla, 408. 459, 496 

 Myriothelia, 241 

 Myriotrochus, 349 

 Mynnecocystus, 488 

 Myrmecophaga, 636 

 Myrmecophily, 169 

 Myrmeleo, 481, 483 

 Mysididse, 429 

 Mysis, 428, 429 

 Mysticetae, 645, 646 

 Mytilus, 363 

 Myxicolida, 313 

 Myxidium, 213, 217 

 Myxine, 557 

 Myxobolus, 217 

 Myxomycetes, 198 

 Myxospongiae, 225, 227 

 Myxosporida, 217 

 Myzobdella, 315 

 Myzontes, 557 



Nacre, 361 

 Nageli. 24, 54, 55 

 Naiadse, 367 

 Naididse, 315 

 Nails, 618 

 Nais, 307 

 Naja. 601 

 Nandu, 613 

 Nanomia, 244. 245 

 Narcomedusae, 239, 242 

 Narwal, 646 

 Nasal bone, 523 

 Nassa, cleavage of, 154 

 Nassellaria, 196 

 Natatores, 614 



Naticidae, 380 

 Natural selection, 44 

 Nauplius, 37, 413 

 Nauplius eye, 412 

 Nausithog, 134, 250 

 Nautilidae, 394 

 Nautilus, 387, 394 

 Nearctic region, 176. 178 

 Nebalia, 427 

 Nectonema, 304 

 Nectonemertes, 291 

 Necturus, 587 

 Nectocalyx, 243 

 Needham's sac, 392 

 Nematocysts, 229 

 Nematoda, 298 

 Nemathelminthes, 298 

 Nematophora, 228 

 Nematus, 486 

 Nemerteans, 289 

 Nemertini, 289 

 Nemocera, 492 

 Nemognatha, 483 

 Nemopsis, 242 

 Neocrinoidea, 342 

 Neogaea, 177 

 Neomenia, 358 

 Neotropical region, 176, 177 

 Nephilis, 321 

 Nephridia, 116, 308 

 Nephrostome, 116 

 Nepidae, 489 

 Neptunus, 437 

 Nereidae, 313 

 Nereis, 311, 312, 313 

 Nerve-end buds, 537 

 Nerve fibres, 94 

 Nerve hillock, 537 

 Nerve roots, 533 

 Nerves of vertebrates, 535 

 Nervous system, 122 

 Nervous tissue, 94 

 Nettle bodies, 205 

 Nettle cells, 229 

 Neural arch, 516 

 Neural plates, 594 

 Neural spine, 517 

 Neurapophysis, 517 



