Morphology, 5 
Morula, 43 
Mosasaurus maximus, 500 
Mosquito, 357 
Moths, 358 
Mound bird, 546 
Mouse, 586 
Mucous canal of fishes, 442 
Mud dauber, 383 
Mud fish, 432 
puppy, 478 
sun fish, 443 
Mullet, 448 
Mus, 586 
Musca domestica, 355 
Musical fishes, 448 
Music of mammals, 569 
Mussa, 80 
Mussel, edible, 248 
development of, 254 
Mustela foina, 617 
Mustelus canis, 420 
levis, 420 
vulgaris, 420 
Muzir, 604 
Mya arenaria, 222 
Mygale avicularia, 363 
Hentzii, 363 
Myliobatis, 416, 424 
fremenvillii, 422 
Mylodon, 579 
Myriopoda, 336, 365 
Myriotrochus Rinkii, 216 
Myriozoum subgracile, 188 
Mysis, 293 
Mysticete, 592 
Mytilus edulis, 228 
Myxine, 409 
Naga, 499 
Nanemys guttatus, 510 
Narwhale, 594 
Nasua, 615 
Natatores, 544 
INDEX. 713 
Natica heros, anatomy of, 241 
Natrix torquata, 495 
Nauplius, 274 
Nautilus pompilius, 260 
Nebalia, 291 
bipes, 292 
Necturus lateralis, 478 
| Nematelminthes, development of, 
122 
structure of, 12i, 133 
Nematodes, 125, 138 
Nematogene, 99 
Nemertian worms, 154 
Nemertina, development of, 155 
structure of, 154, 157 
Neochanna, 452 
Nephila plumipes, 343 
Nereis virens, anatomy of, 169 
Nervous system, 638 
Nervous system of ctenophores, 
92 
insects, 317 
hydrozoa, 62, 65 
Nests of birds, 536 
Neuroptera, 349 
Neurula stage of leeches, 166 
worms, 168 
Nighthawk, 551 
Noctiluca miliaris, 33 
Noises produced by fishes, 442, 
443 
Notacanthus, 446 
Notochord of ascidians, 396 
Notommata, 135 
Nototrema marsupiatum, 485 
Nudibranch molluscs, 245 
Numerius longirostris, 545 
Nummulites, 25 
Nurse of trematode worms, 107 
| Nyctea nivea, 549 
Ocuxina, 80 
Octacnemus bythius, 392 
Octopod cephalopoda, 260 
