348 



INDEX. 



MoUuscoidea, 118, 231. 

 Monad, 137. 

 Monera, 137, 140. 

 Monodelphia, 282. 

 Monotremata, 58, 79, 80, 280, 



282. 

 Monomya, 217. 

 Monophyodont, 285. 

 Monotremes, 59, 80, 280, 281. 

 Morphology, xvii, 28. 

 Morula, 70, 72. 

 Moss-corals, 231. 

 Moth, Brown-tail, 205. 

 Moth, Humming-bird Hawk-, 



206. 

 Moth, Little Ermine, 205. 

 •Mud-flshes, 259. 

 Muscle, 42. 

 Muscle-plates, 244. 

 Muscles of vertebrates, 241, 



244. 

 Mushroom coral, 156. 

 Musk deer, 294. 

 Mussel, Eresh-water, 210, 218. 

 Mussel, Eiver, 218. 

 Mussel, Sea, 217. 

 Myriopoda, 186, 196, 197. 

 Myxopod, 137, 158. 



N atatores, 275. 

 Natural selection, 51. 

 Nauplius, 187, 188. 

 Nautilus, Paper, 226, 228, 230. 

 Nautilus, Pearly, 226, 229. 

 Nemathelminthes, 178, 181. 

 Nematocysts, 148. 

 Nematodes, 181. 

 Nemertines, 181. 

 Nephridia, 48, 184. 

 Nerves, 33. 

 Nerves, cranial, 244. 

 Nerves of starfish, 174. 

 Nests of spiders, 194. 



Neuroptera, 203. 



Newts, 265. 



Notochord, xvii, 40, 76, 78, 



113, 239, 240, 251. 

 Nucleolus, xvii, 18, 42, 46, 67, 



76. 

 Nucleus (of bone), 58. 

 Nucleus, xvii, (of cell) 18, 42, 



46, 67, 76. 

 Nucleus, division of, xvii, 21, 

 Nummulite, 135. 



Occipital condyles, 247. 

 Ocelli, 35, 160, 198. 

 Ootocoralla, 155. 

 Odontophore, 219, 220, 221. 

 Odontornithes, 272. 

 Olfactory bulbs, 33. 

 Oligochaeta, 183. 

 Ontogeny, xvii, 59, 62, 113. 

 Operculum, 221, 222, 249. 

 Ophidia, 269. 

 Ophiuridse, 173. 

 Opisthocoelous vertebrae, 270. 

 Opossum, 282. 

 Opossum shrimp. 31, 32. 83. 

 Orders, 121. 

 Organ, 25, 111. 

 Organism, xvii. 

 Organ, coral, 155, 167. 

 Origin of species, 49. 

 Ornithodelphia (see Mono- 

 tremes), 79, 282. 

 Orthoptera, 201. 

 Osculum, 144. 

 Ostrich, 273, 274. 

 Otooyst, 31, 32, 160, 219, 220. 

 Otolith, 31, 32. 

 Ova, amoeboid, 144, 160. 

 Oviparous, xvii. 

 Ovum, ()T. 

 Oyster, 213, 217. 

 Oxygen, 9, 10, 47. 



