INDEX 



Shells in lakes,, Deposit of, 57 ; in the ocean, 63 



Shetland Islands, Action of the sea on the, 59 



Sigillarias, 222 



Silchester, 45 



Silica, 40 



Silurian Period, Scorpions and insects in the, 203 ; surface of 

 the earth in the, 208 ; rivers and streams, 209 ; coral 

 reefs, 210 ; fish, 210 ; plant life, 210 ; Britain, 211 



Silurian rocks, 202 



Sivatherium, The, 266 



Snail-shells in lakes, 57 



Snakes, First appearance of, 255 



Snow and Ice Age, 68 



Sonora, Earthquake at, 160 



Sperm Whale, The, 274 



Sphenodon, The, 230 



"Spy men," 286 



Stars, The, 91 



Steam a cause of earthquakes 



Stegosaurus, The, 242 



Stone Age, The, 287 



Stones smoothed by water, 55 



Strata, The earth's, 78 



Strokkur geyser in Iceland, 141 



Submarine volcanoes, 187 



Subterranean caves, how caused, 195 



Sun, The, 90; as an abode of life, 118 



Tapir, The, 273 



Temperature of borings, The, 83; of the Moon, 124; of 

 Mars, 126 



306 



