190 Observations on some Parts ofMr. De la Beche's Pa/J^r 



country affords, and then, by its means, naming and classifying 

 strata in accordance with our own, and in fact, absolutely 

 identifying them with certain terms of our series ? 



A good example of this may perhaps be found in Dr. Buck- 

 land's paper On the Irawadi River. We are told that shells 

 there found have been identified by Mr. Sowerby as those of 

 our London clay ; while we are left to conclude that others 

 were likewise found which that gentleman could not identify. 

 We may also, I think, justly infer, that on a more extended 

 examination of the country, many would be found in the 

 same " dark slaty limestone," widely differing from any of our 

 London clay fossils. Now every geologist will, perhaps, 

 confess that " the London clay" presents as narrow a field for 

 observation as any of our strata, being principally confined to 

 two small basins in our island ; while the neighbouring one at 

 Paris affords an example of the gi'eat variance in appearance 

 and mineralogical details, of an equivalent formation, even 

 when its organic contents are partly the same. Does it ap- 

 pear, then, scientific, or even reasonable, from two patches of 

 clay in a small island, as the type, together with a few doubt- 

 ful auxiliaries on the Continent, to affirm positively, — that it 

 may be considered as now established on the authority of 

 Mr. Crawfurd's notes and specimens, that the Burmese country 

 contains London clay ? In the same way Mr. Colebrooke is 

 represented as having established the occurrence of this bed 

 in the N.E. corner of Bengal. Even if other beds of great 

 extent in Europe could be thought recognizable from certain 

 fossils in distant parts, of which we may be allowed to doubt, 

 surely " theLondon claj-," which we cannot show the existence 

 of even in the very next basin to that from which it derives its 

 name, cannot be discovered with an)' degree of certainty. I 

 would therefore ask Mr. De la Beche, as a member of the 

 Geological Society, present very likely when the above-men- 

 tioned paper was read, whether, consistently with his state- 

 ments about temperature and the distribution of animal and 

 vegetable life, he can agree in thus assigning " theLondon clay" 

 a locality on nearly the opposite side of our globe? — in a part 

 where, unless we uphold the Wernerian theory of beds encir- 

 cling the earth like the coats of an onion, we must allow the 

 probability of depositions having been made perfectly inde- 

 pendent of those on which we live, if we may not actually con- 

 clude that they are so ; — in a latitude also, where every ob- 

 jection made with regard to difference of temperature will hold 

 good to a great degree. 



In confirmation of the above, the following passage of 

 Cuvier's work (Jameson, page 11) may perhaps be brought 



forward : 



