Sea-lion, 341. 
Sea-slug, 253. 
5) 
Sea-urchin, circulation in, 104. 
se described, 252. 
ae digestion in, 75, 91. 
Rs mouth of, 55. 
Bs respiration in, 111. 
ue shell of, 129, 378. 
a spines of, 129, 378. 
cs teeth of, 63. 
Sea-worms, 272. 
Secretion, 120. 
Self-division, 18S. 
Senses, 173. 
Sepia, 268, 352. 
Serpents, skulls of, 73. 
Serpula, 272. 
Sertularians, 288, 350. 
Sete, 271. 
Setophaga, 325. 
Shark, described, 302. 
“ eggs of, 191. 
“© skeleton of, 135. 
Shells of Crustaceans, 130, 272. 
cs Mollusks, 131, 257, 260. 
Sea-urchins, 129, 378. 
Shrew, 333. 
Shrimp, 274. 
Sight, 177. 
Silk-worm, 293. 
Simia, 356. 
Siphonophora, 350. 
Siphuncle, 267. 
Siredon, 306. 
Siren, 306. 
Sirenians, 336, 355. 
Size of Animals, 214. 
Skeleton, 125. 
Skin, 125, 126. 
Skull, 142, 380. 
Sloth, 330. 
Slug, 262. 
Smell, 175. 
Snail, circulation in, 105. 
‘© described, 260. 
‘© digestion in, 79. 
“mouth and teeth of, 56, 64. 
«© prehension of, 51. 
* shell of, 132. 
“© tentacles of, 17S. 
Snakes, described, 308, 354. 
s locomotion of, 155, 159. 
es prehension of, 53. 
Snapping-bugs, 287. 
Snipe, 319. 
Somite, 380, 
Songsters, 325. 
Sorex, 333. 
INDEX. 
Sow-bug, 274. 
Sparrow, 325, 327. 
Species, 227. 
Sperm-whale, 334. 
Sphinx-moth, 291, 353. 
Bo described, 308, 354. 
digestion in, 78. 
“«  Tegs of, 159. 
‘© mouth of, 59. 
‘prehension of, 52. 
“© spiracles of, 115. 
Spinal Column, 148. 
“Cord, 166, 169, 172. 
Spinnerets of Caterpillar, 292. 
se Spider, 280. 
Spiracles, 113. 
Sponge, 49, 128, 235, 349, 370. 
Squalus, 354. 
Squid, 155, 269. 
Squirrel, 332. 
Star-fish, anatomy of, 159. 
ss circulation in, 104. 
a described, 250. 
Stilt, 319. 
Stomachs, 83, 86, 88. 
Stork, 319. 
Stridulation, 185. 
Strombus, 265, 352. 
Struthio, 355. 
Sturgeon, 53, 302. 
Subkingdom, 227. 
Sun-fish, 251. 
Survival of the Fittest, 220. 
Suture, 145. 
Swallow, 326. 
Swan, 318. 
Swift, 325. 
Sycon, 349. 
Symmetry, 215. 
Synovia, 145. 
Tanta, 271, 352 
Tanagers, 327. 
Tapetum, 181. 
Tape-worm, 49, 271, 379. 
Tapir, 213, 338, 383. 
Taste, 174. 
Teeth, 38, 62, 65, 66, 68, 70. 
Teleosts, 302, 354. 
Temperature of Animals, 119. 
Tendons, 154. 
Tentacles, 50. 
Terebra, 264. 
ss digestion in, 91. 
“ feeding, 51. 
ae locomotion of, 158. 
J nervous system, 165. 
ae respiration in, 111. 
