64 



LA TOUCHE : GEOLOGY OF NORTHERN SHAN STATES. 



tions more or less closely with those in far distant regions, in which 

 the geological nomenclature is already established. Thus it is pos- 

 sible in the Shan States to give the well-known European designa- 

 tions to those larger groups of strata which we call systems : 

 and it would be mere affectation to call these groups by local 

 names, where there is such a close agreement in the whole assem- 

 blage of fossils as we find in the present case. For although there 

 may be truth in the contention that this very agreement in specific 

 characters is evidence that the beds in which the fossils occur can- 

 not be strictly contemporaneous, when we are dealing with localities 

 at great distances apart (since it presupposes a migration of forms, 

 which must have occupied a certain amount of time, from one area 

 to another), yet such an objection cannot apply to the general con- 

 temporaneity of a whole system. If, moreover, as seems to be 

 generally admitted, the present zonal distribution of climate on the 

 earth's surface was not established till late in the world's history, 

 the objections to the contemporaneous existence of identical forms 

 of life in areas widely differing in latitude lose much of their force. 

 In the following descriptions of the fossiliferous rocks of the 

 Shan States, therefore, I propose to use the 



Names of sub-divisions. ... , , . 



well-known names already m use as applied 

 to the systems ; but the case is different as regards the sub-divisions 

 of which those systems are composed. Until the geology of Western 

 China, especially of Yunnan, and of Central Asia is better known, it is 

 not possible to trace these minor divisions beyond the confines 

 of the Shan States, and as some of them appear to be as closely 

 connected by their fossil contents with strata already described in North 

 America as with those of northern Europe, very much remains to be 

 done before we can determine which system of classification is to be 

 adopted. Moreover, as our future surveys will probably take the Shan 

 States as a centre, it is convenient to employ a local standard of position 

 to which to refer. It is only when the formations have been linked 

 up with those beyond the barrier of unexplored or little-known terri- 

 tory that it will be possible to adopt a more widely accepted 

 nomenclature. 



The name ' Ordovician,' as that of a separate system, has not 

 Discrepancy between until now been employed by Indian geologists, 

 Burmese and Himala- and the reasons for its use here perhaps re- 

 yan geology. quire some explanation My object in doing 



so is to emphasise at the outset the great want of accordance 



