268 LEAVES EEOM THE 



most interesting point of view, when compeared with the 

 fossil evidences of the development of this sub-family in 

 the ancient seas of our globe. Professor Owen, in his 

 valuable History of British Fossil Reptiles, describes 

 no less than eleven well-defined fossil species of chelone 

 found in Britain, to say nothing of fragments. Such a 

 catalogue, as he justly observes, leads to conclusions of 

 much greater interest than the previous opinions respect- 

 ing the chelonites of the London clay could have sug- 

 gested. 



Wliilst (writes the Professor) these fossils were supposed to have 

 belonged to a freshwater genus, the difference between the present 

 fauna and that of the eocene period, in reference to the chelonian 

 order, was not very great ; since the Emys {cistuda) Eurojiaa still 

 abounds on the continent after which it is named, and hves long in 

 our own islands in suitable localities. But the case assumes a 

 very different aspect when we come to the conviction, that the 

 majority of the eocene chelonites belong to the true marine genus 

 chelone ; and that the number of species of these extinct turtles 

 already obtained from so limited a space as the Isle of Sheppy, 

 exceeds that of the species of chelone now known to exist through- 

 out the globe. 



The Professor comes to no hasty conclusion, when he 

 states that the ancient ocean of the eocene epoch was 

 much less sparingly inhabited by turtles than that which 

 now washes the shores of our globe ; and that these 

 extinct turtles presented a greater variety of specific 

 modifications than are known in the seas of the warmer 

 latitudes of the present day. Nor does the inference 

 stop here; for, as he well says in continuation, the in- 

 dications which the English eocene turtles, in conjunction 

 with other organic remains from the same formation, 

 afford of the warmer climate of the latitude in which 

 they lived, as compared with that which prevails there 

 in the present day, accord with those which all the 

 organic remains of the oldest tertiary deposits have 

 hitherto yielded in reference to this interesting point. 



