240 



EVOLUTION IN THE PAST 



Sharks (con/.) 



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, 19 



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 



