240 



EVOLUTION IN THE PAST 



Sharks {cont.) — 



Triassic, 75 



Jurassic, 87 



Cretaceous, 104 



Eocene, 135 



Miocene, 167 



Angel, 87 



Blue, 135 



Comb-toothed, 87 



Cow, 39 



Hammer-headed, 167 



Porbeagle, 104 



Port Jackson, 36, 57, 87 



Thresher, 167 

 Shearwaters, 150 

 Sheep, 158, 189 

 Shell-mounds, Danish, 211 

 Ship- worms, 85 

 Shrews, 118, 149 

 Shrikes, 151 

 Shrimps — ■ 



Cambrian, ig 



Ordovician, 26 



Devonian, 42 



Carboniferous, 56 



Triassic, 75 



Jurassic, 86 



Cretaceous, 106 

 Siberia, 190, 194, 197 

 Sigillaria, 50, 67, 70, 89 

 Silures, 213 

 Silurian Period, 28 

 Sirenians, 130, 150 

 Sivatherium, 177 

 Siwalik formation, 173 

 Skates. See Rays 

 Sloths, Ground — 



Miocene, 161 



Pliocene, 185 



Pleistocene, 204 



Ancestry, 162 

 Snails. See Gastropods, Pteropods 

 — Land, 44, 52 

 Snake-flies, 52 

 Snakes, 135, 167 

 Sparassodonts, 164 

 Speech, 190, 198 

 Sphaerexochus, 34 

 Sphenodon, 62 



Sphenophyllum, 27, 47, 50, 70 

 Spiders, 52, 152 

 Spinning, 212 



Spirifer, 32, 45, 55, 66, 84 

 Spitzbergen, 89, 154 

 Sponges — 



Cambrian, 16 



Ordovician, 21 



Silurian, 28 



Devonian, 47 



Carboniferous, 52 



Permian, 66 



Triassic, 71 



Jurassic, 82 



Cretaceous, no 



Calcareous, 47, 71 

 Spores, 7, 48 

 Sprats, 88 

 Spring-tails, 52 

 Spruces, 68, 70, 189 

 Spy human remains, 198 

 Squalodon, 150, 165 

 Squids, 86 

 Squirrels, 124, 148 

 Starfishes — 



Cambrian, 17 



Ordovician, 23 



Silurian, 30 



Devonian, 46 



Carboniferous, 54 



Permian, 66 



Jurassic, 83 

 Starlings, 132 

 Staurocephalus, 34 

 Stegocephs, 58, 61, 76 

 — ancestry, 59 

 Stegodons, 175 

 Stegosaurus, 91, 98 

 Stick-insects, 52 

 Stilts, 151 



Storks, 112, 131, 166 

 Streptelasma, 21 

 Sturgeon, 88, 105, 136 

 Sun-stars, 83 

 Survival of the Fittest, 5 

 Swifts, 132 

 Swine — 



Eocene, 125 



Oligocene, 143 



Miocene, 159 



Pliocene, Earlier, 172, 176 



— Later, 183 

 Syndyoceras, 157 

 Synxiphosura. See King-crabs 

 Systemodon, 121 



