INDEX AND GLOSSARY. 



213 



for carrying their young, as the 

 opossum ; gestation of, 151. 



Marsupites, 5201. 



Mastication, 77. 



Mastodon, 204. 



Matrix, the organ in which the em- 

 bryo is developed, 121. 



Medulla oblongata, continuation of 

 the brain into the back-bone. 



Medusa, jelly-like animals living in 

 the sea, xviii. ; development of, 

 132 ; digestive organs, 70. 



Megalobatrachus, 177. 



Megalosaurus, 197. 



Melocrinus amphora, 192. 



Memory, 44. 



Menobfanchus, 169, 177. 



Menopdma, 169, 177. 



Merganser, an aquatic bird allied to 

 the goose, 42, 161. 



Metacarpus, the wrist, 59. 



Metamorphic rocks, 184. 



Metamorphosis, 119, 142 ; of the silk- 

 worm, 143 ; canker-worm, 144 ; 

 duck-barnacle, 345; star-fish, 146; 

 comatula, 147. 



Micraster cor-anguinum, 201. 



Miocene formation, 187. 



Modern age, 190, 203. 



Molar teeth, 81. 



Molecules, very minute particles, 



Mollusks, soft animals of the snail 

 and oyster kind ; heart of, 90 ; 

 liver of, 101 ; number of, 3 ; meta- 

 morphosis of, 147. 



Monkey, teeth of, 81. 



Morioculus, mode of carrying eggs, 

 106. 



Moulting, the shedding of feathers, 

 hair, &c. 98. 



Muscles, 48 ; disposition of, in in- 

 sects, 53 ; in fishes, 54 ; in birds, 

 55. 



Muscular tissue, 15. 



Myxine glutinosa, its eye, 31. 



Natatores, birds with webbed feet 

 for swimming, xvi. 



Natica, tongue of, 78 ; heart of, 91. 



Nautili, xvii. 



Neptunian rocks, 183. 



Nereis, jaws of, 78 ; gills of, 57 ; eye, 

 29. 



Nervous system, 20 ; in mammals, 

 21 ; in articulates, 22 ; in crusta- 

 ceans, 22 ; in radiates, 23. 



Nervous tissue, 15. 



Nest of Baltimore oriole, 46 ; of tai- 

 lor bird, 46 ; of Ploceus, 47. 



Nomenclature, the naming of ob- 

 jects and their classes, family, 

 &c. 



Notosaurus, 196. 



Nucleolites, 200. 



Nucleolus, a little nucleus, 14. 



Nucleus, a kernel, or condensed 

 central portion, 14. 



Nudibranchiates, mollusks having 

 the gills floating externally, fig. 91. 



Nummulites, 202. 



Nurses, of Cercaria, 130 ; ants and 

 bees, 132. 



Nutrition, 72. 



Ocelli, minute eyes, 28. 

 (Esophagus, the gullet, 22, 75. 

 Olfactory, pertaining to the sense of 



smell, '21, 36. 

 Omnivora, feeding upon all kinds of 



food, 83. 



Oolitic formation, 186. 

 Operculum, a cover for the aperture 



of a shell. 

 Opliidians, animals of the serpent 



kind, xvi. 

 Optic nerves, 24. 

 Orbits, 24. 

 Orders, xiv. 

 Organism, 7, 13. 

 Organized bodies, general properties 



of, 11 ; elementary structure, 12. 

 Ornithichuites, 197. 

 Orthoceras fusiforme, 193. 

 Osseous tissue, 15. 

 Otolites, little bones in the ears of 



mollusks and Crustacea, 35. 

 Ovary, the organ in which eggs 



originate, 104. 

 Oviduct, the passage through which 



the egg is excluded, 105. 

 Oviparous, producing eggs, 103. 

 Ovis montana, 160. 

 Ovo-viviparous, animals which hatch 



their eggs within their body, 105. 

 Ovulation, the production of eggs, 



105. 



Oxygen, its consumption in respira- 

 tion, 17, 95. 



Pachydermata, thick-skinned ani- 

 mals, like the elephant, hog, &c. 

 82 202. 



Paleontology, 183. 



Paleozoic age, 190, 191. 



Paleotherium, 202. 



