586 HISTORY OF GEOLOGY. 



represent some of the highly-compact and crystal- 

 line marbles of Italy and Greece. This view was 

 confirmed by subsequent investigations; and the 

 correspondence was traced, not only in the general 

 body of the formations, but in the occurrence of the 

 red marl at its bottom, and the green sand and 

 chalk at its top. 



The talents and the knowledge which such tasks 

 require are of no ordinary kind ; nor, even with a 

 consummate acquaintaince with the well-ascertained 

 formations, can the place of problematical strata be 

 decided without immense labour. Thus the exami- 

 nation and delineation of hundreds of shells by the 

 most skilful conchologists, has been thought neces- 

 sary in order to determine whether the calcareous 

 beds of Maestricht and of Gosau are or are not 

 intermediate, as to their organic contents, between 

 the chalk and the tertiary formations. And scarcely 

 any point of geological classification can be settled 

 without a similar union of the accomplished natu- 

 ralist with the laborious geological collector. 



It follows from the views already presented of 

 this part of geology, that no attempt to apply to 

 distant countries the names by which the well- 

 known European strata have been described, can be 

 of any value, if not accompanied by a corresponding 

 attempt to show how far the European series is 

 really applicable. This must be borne in mind in 

 estimating the import of the geological accounts 

 which have been given of various parts of Asia, 



