432 
INDEX. 
Sight, of Ccelenterates, 180. 
“ of Mollusks, 181. 
“ of Vertebrates, 183. 
Silk-gland, 40. 
Silk-worm, 303. 
Simla, 357, 3o3, 3oo, 3o6. 
Sinuses, 138. 
Siphon, 113, 226. 
Siphonophora, 248, 104. 
Siphuncle, 279, 247. 
Sirenia, 349, 73, 343. 
“ see Dugong. 
Size of Animals, 221. 
Skeleton, of Arthropoda, 131. 
“ of Birds, 144, 116. 
“ of Coelenterates, 130. 
“ of Crocodile, 113. 
“ of Echiuoderms, 130. 
“ of Fish, 138, 144, 145, 112. 
“ of limbs, 146. 
“ Lion, 139, 106. 
“ Mammals, 139, 106, 114, 117— 
120 . 
“ Mollusks, 133. 
“ Reptiles, 113. 115. 
“ of skull, 141, 108-111. 
“ of Tortoise, 115. 
“ of Vertebrates, 134. 
“ of Vulture, 116. 
“ of Whale, 114. 
“ see Exoskeleton. 
Skin of Invertebrates, 127. ' 
“ of Vertebrates, 12S. 
Skin-muscle, 156. 
Skull, 141, 37, 108-111, 353, 354, 359, 
360. 
Slater, 2S6, 251. 
Slug, 275, 232. 
Smell, 177. 
Snail, 272. 
“ alimentary canal of, 80, 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. 
u mode of feeding, 52. 
“ mouth of, 56. 
“ nervous system of, 168, 134, 154. 
“ operculum of, 114, 134, 228. 
“ respiration in, 116, 45. 
“ shell of, 133, 100, 228, 231-246. 
siphon of, 228. 
“ smell of, 178. 
“ teeth of, 65, 29. 
“ tentacles of, 176, 154, 228. 
Snail, see Gasteropoda. 
Snake, 320, 65, 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, S2. 
“ tongue of, 62. 
“ 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, 286. 
Sparrow, 339. 
Species, defined, 235. 
“ number of, 221. 
Sperm-cells, 196. 
Sperm-whale, see Whale. 
Sphinx-moth, 303, 43, 136. 
Spider, classification of, 289, 260. 
“ alimentary canal of, 79. 
“ appendages of, 162, 25. 
“ circulation in, 106. 
“ fangs of, 53, 18, 25. 
“ mouth of, 60, 25. 
“ respiration in, 116. 
“ spinnerets of, 2S9, 25, 261. 
“ web of, 289, 260- 
Spinal column, 141. 
“ cord, 175, 137. 
Spindle-shell, 236. 
Spinneret of Spider, 289, 25, 261. 
“ of Caterpillar, 301, 2 7 6. 
Spiracle, 114, 293, 79. 
Splint-bone, 147. 
Sponge, 244, 189, 190. 
“ alimentary canal of, 76. 
“ anatomy of, 189. 
“ egg of, 194, 163. 
“ feeding of, 50, 1S9. 
“ respiration in, 112. 
“ skeleton of, 129, 190. 
Squash-bug, 297. 
Squid, 280. 
“ locomotion of, 15S. 
“ see Cuttle-fish. 
Squirrel, 346. 
Stag, 352, 345. 
Star-fish, alimentary canal of, 76, 126, 
210 . 
“ anatomy of, 126. 
“ circulation in, 105. 
“ classification of, 25S. 
“ development of, 20S. 
