PALEONTOLOGY. 155- 



away, which would have been saved by the slightest ac- 

 quaintance with palaeontology."* 



The mode of procedure, however, indicated in the 

 above examples necessarily presupposes that the strati- 

 grapliical succession has first been established in some 

 other locality where the relative position of the beds is 

 clearly seen, so that there can be no doubt about the 

 comparative t age of the faunas they contain ; in other 

 words, the successional order of the faunas must first 

 be clearly ascertained before a knowledge of them can 

 assist in elucidation of faulted or outlying districts; 

 while these conditions have not been fulfilled palseon- 

 tological reasoning is very likely to lead the observer 

 astray. 



Another caution must also be given, viz. : that the 

 knowledge thus obtained will only apply to a limited 

 area ; this is a natural result of the distribution of life 

 in " provinces," during past as well as present time ; 

 consequently in comparing districts which are wide 

 apart we cannot be sure of the absolute contempo- 

 raneity of deposits which may contain similar fossils, 

 we can only say that the relative order of succession is 

 the same in both regions. Mr. Jukes says, " It is yet 

 doubtful whether these specific differences, existing to- 

 gether with generic identities, be due to a want of exact 

 synchronism in the age of the beds or to the geographi- 

 cal distribution and limitation of the life of the period, 

 whether in fact they are the result of time or space." 

 Where, however, the areas are widely separated, the for- 

 mer is the more probable cause, and in correlating the 



* " Manual of Geology," Jukes and Geikie, p. 512. 



