502 



CENOZOIC TIME. 



The Middle and Upper Eocene abound in remains of Vertebrate 

 life, of all grades, Fishes, Reptiles, Birds, and Mammals. The fishes 

 were of the orders of Teliosts (Herring, etc.), Ganoids or Gars, and 

 Sharks ; Teliosts and Sharks predominating greatly over the Ganoids, 

 and the Sharks much exceeding in size, variety, and numbers those 

 now living. The teeth of the latter (Figs. 914 to 916) are ex- 

 Fig. 917. 



Tooth of Zeuglodon cetoides (X?s)- 



ceedingly abundant, in both the Eocene and the Miocene ; and some of 

 the triangular teeth of Carcharodon megalodon Ag. are six and a half 

 inches long, and five broad at base. They are found at Gay Head, 

 as well as in the States south and southwest. 



The Reptiles embraced species of Turtles, several of true Crocodiles, 

 and Snakes twenty feet long and shorter. 



The Birds discovered in the Eocene and Miocene beds include sev- 



