246 



INDEX AND GLOSSARY. 



Nutrition, 96. 



Ocelli, minute eyes, 52. 



Octopus, arms of, 180. 



Odors, 61. 



(Esophagus, the gullet, 46, 99. 



Olfactory, pertaining to the sense 



of smell, 45, 60. 

 Omnivora, feeding upon all kinds 



of food, 107. 

 Oolitic formation, 218. 

 Operculum, a cover for the aperture 



of a shell. 

 Ophidians, animals of the serpent 



kind, 20. 

 Optic nerves, 48. 

 Orbits, 48. 

 Orders, 18. 

 Organism, 37. 

 Organized bodies, general properties 



of, 35 ; elementary structure, 36, 



37. 



Ornithichnites, 229. 

 Orthoceras fusiforme, 225. 

 Osseous tissue, 39. 

 Otolites, little bones in the ears of 



mollusks and Crustacea, 59. 

 Ovary, the organ in which eggs 



originate, 133. . 

 Oviduct, the passage through which 



the egg is excluded, 134. 

 Oviparous, producing eggs, 131. 

 Ovis montana, 192. 

 Ovo-viviparous, animals which 



hatch their eggs within their 



body, 135. 

 Ovulation, the production of eggs, 



134. 



Oxygen, its consumption in respira- 

 tion, 41, 113, 121. 



Pachydermata, thick-skinned ani- 

 mals, like the elephant, hog, &c., 

 107, 234. 



Pacing, 91. 



Paleont61ogy, 215. 



Palaeozoic age, 222, 223. 



Paleotherium, 234. 



Palpation, the exercise of the touch, 

 64. 



Palpi, jointed organs for touch, 

 about the mo\ith of insects, 64. 



Papilla, a little pimple, 62. 



Paramecia, reproduction of, 157. 



Parasitic, living on other objects. 



Passerine, birds of the sparrow kind, 

 201. 



Peduncle or Pedicle, a slender stem. 



Pelvis, the cavity formed by the 

 hip bones, 87. 



Pentacrinus, 231 ; metamorphosis 

 of, 180. 



Perception, 67. 



Perchers, a class of birds, 20. 



Peripherie, exterior surface, 152. 



Peristaltic motion, 100. 



Petrifactions, 215. 



Phalanges, 83. 



Pigment, a coloring substance, 40. 



Pituitary membrane, 61. 



Placenta, the organ by which the 

 embryo of mammals is attached 

 to the mother, 152. 



Placoids, fishes with a rough skin, 

 like the shark or skate, 20. 



Planaria, its digestive apparatus, 

 98 ; an eye of, 53. 



Plant-lice. See Aphides. 



Plants compared with animals, 41. 



Platynotus, 225. 



Pleiocene formation, 219. 



Plesiosaurus, 229, 232. 



Pleurotomaria, 233. 



Ploceus Philippinus, nest of, 70. 



Plutonic rocks, 215. 



Podurella, mode of leaping, 92 ; em- 

 bryo of, 144 ; egg of, 133. 



Polyps, a small animal fixed at one 

 end, with numerous flexible feel- 

 ers at the other, 27, 53; repro- 

 duction of, 158. 



Prehension, act of grasping, 109. 



Primary age, 222. 



Primitive stripe, 143. 



Progression, 88, 90. 



Proligerous, the part of the egg 

 bearing the embryo, 141. 



Proteus, 209. 



Protosaurus, 228. 



Protractile, capable of being ex- 

 tended. 



Pterichthys, 226. 



Pter6coma pinnata, 231. 



Pterodactylus, 230. 



Pteropods, mollusks with wing-like 

 expansions for swimming, 22. 



Pulmonary, relating to the lungs, 

 116. 



Pulmonates, mollusks which 

 respire air, 22. 



Pupil ; 40. 



Pyrula. egg-cases of. 135. 



Quadrumanous, four-handed, 201 



