INDEX. 
411 
Skin of Invertebrates, 127. 
“ of Vertebrates, 128. 
Skull, 141. 
Slater, 2S4, 251. 
Slug, 274, 282. 
Smell, 177. 
Snail, 272. 
“ alimentary canal of, SO, 45. 
“ anatomy of, 45. 
“ circulation in, 106, 45. 
“ eye of, 181,154. 
“ gills of, 113. 
“ gizzard of, 64. 
“ heart of, 45. 
“ jaw of, 56, 20. 
“ larva of, 176. 
“ locomotion of, 161. 
“ lung of, 116, 274, 45^ 
“ mode of feeding, 52. 
“ mouth of, 56. 
“ nervous system of, 16S, 134,154. 
“ operculum of, 114, 134, 228. 
“ respiration in, 116, 45, 228. 
“ shell of, 133, 100, 228, 233-246. 
“ siphon of, 228. 
“ smell of, 178. 
“ teeth of, 65, 20. 
“ tentacles of, 176,154, 228. 
“ see Gasteropoda. 
Snake, 320, 298, 299. 
“ deglutition of, 73. 
“ locomotion of, 162. 
“ lungs of, 119, 84. 
“ poison apparatus of, 6S, 33. 
“ scales of, 135. 
“ skull of, 37. 
“ stomach of, 82. 
“ tongue of, 61. 
“ Vertebrae of, 140. 
“ voice of, 189. 
“ see Boa, Ophidia, Reptilia. 
Snapping-bug, 299. 
Snipe, 332. 
Solaster, 260. 
Somite, 392. 
Songsters, 338. 
Sorex, 346, 338. 
Sow-bug, 285. 
Sparrow, 339. 
Species, defined, 235. 
“ number of, 221. 
Sperm-whale, see Whale. 
Sphinx-moth, 303, 43. 
Spider, classification of, 2S9, 260. 
“ alimentary canal of, 79. 
“ appendages of, 25. 
“ circulation in, 106. 
“ fangs of, 53,18, 25. 
“ mouth of, 60, 25. 
k ‘ respiration in, 116. 
“ spinnerets of, 289, 25, 261. 
Spider, web of, 2S9, 260. 
Spinal column, 140. 
“ cord,175. 
Spinneret of Spider, 289, 261. 
“ of Caterpillar, 301, 276. 
Spiracle, 114, 79. 
Spongida, 244, 189, 190. 
alimentary canal of, 76. 
“ anatomy of, 189. 
“ egg of, 194, 163. 
feeding of, 50, 189. 
“ respiration in, 112. 
skeleton of, 129,190, 
Squash-bug, 297, 
Squid, 2S0. 
“ locomotion of, 158. 
“ see Cuttlefish. 
Squirrel, 346. 
Stag, 352, 345. 
Star-fish, alimentary canal of, 76,126. 
“ anatomy of, 126. 
circulation in, 105,126. 
“ classification of, 258. 
“ development of, 208. 
“ digestion in, 92. 
“ locomotion of, 161, 126. 
“ metamorphosis of, 207. 
“ mode of feeding of, 51. 
“ mouth of, 56. 
“ nervous system of, 168,133. 
“ respiration in, 112. 
“ see Echinodermata. 
Stilt, 332. 
Stomach, S2-89. 
“ digestion in, 93. 
Stork, 332. 
Stridulation, 188. 
Strombus, 278, 243. 
Struggle for Life, 226. 
Struthio, 327, 305. 
Sturgeon, 315, 290. 
Subkingdom, 233. 
Sun-fish, 247- 
Sun-star, 260. 
Survival of Fittest, 226. 
Suture, 147. 
Swallow, 340, 328. 
Swan, 331. 
Swift, 335. 
Swimmeret, 282. 
Symmetry, 222. 
Sympathetic nervous system, 175, 146 
Synovia, 147. 
T.enia, see Tape-worm. 
Tanager, 339. 
Tapetum, 184. 
Tape-worm, 264, 216. 
“ feeding of, 49. 
Tapir, 63, 351. 
Taste, 177.. 
