128 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 



of course, simply intimates that strata of this age are well developed 

 in the Jura chain) is now so universally made use of by continental 

 geologists, as well as introduced into the writings of some of the most 

 eminent of our own body when treating of foreign rocks, that any 

 attempt to substitute another local name for it would be almost sure 

 to fail. There need be no apprehension that English geologists, 

 adopting the continentaf term, would run any risk of being robbed 

 of the honour of having first defined the system ; for, even should 

 the history of this part of geology be lost, the names of Portland 

 stone, Kimmeridge clay, Oxford clay, &C.5 which are met with in the 

 writings of all the best foreign authors, sufficiently attest the fact. 



Finally, I have only to reiterate the opinion hinted at in con- 

 cluding the paper to which this is supplementary, that many of the 

 mixed deposits, from the Devonian system upwards, will be found to 

 have originated in " Caspians." 





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