WORK ON THE PALEOZOIC ROCKS. 97 



Sedgwick and Murchison was followed by the more detailed 

 work of Salter, Harkness and others, and especially of 

 Hicks, and it was the fuller observations of these eeolo- 

 gists which rendered possible the still more minute work of 

 Lapworth and others, which brought about the results 

 chronicled in my last article. The reference to the zonal 

 method, as though it were a method instituted within the 

 last fifteen years, was, therefore, hardly just to previous 

 workers, and I gladly take this opportunity of correcting a 

 statement which may have produced a false impression con- 

 cerning the value of the researches of those workers, an 

 impression which, I need hardly say, it was not my intention 

 to produce. 



Though much has been written upon the palaeozoic 

 rocks of Britain and their included fossils during the six 

 months under notice, there is a relative dearth of papers 

 which are strictly stratigraphical ; but as many references 

 are made to the characters of the rocks or fossils of the 

 strata, which it is within my province to consider, brief al- 

 lusion will be made to the more important of them, leaving 

 their fuller consideration for the petrographer or the palae- 

 ontologist. Papers which bear more or less directly on the 

 nature of the Precambrian rocks are naturally numerous, 

 and will be noticed, even when the Precambrian age of the 

 rocks under consideration is a matter of uncertainty, for 

 though the rocks may not be Precambrian, they may never- 

 theless throw some light upon the vexed questions connected 

 with Precambrian rocks. Of the palaeozoic rocks, we find 

 that the lower division has not been the subject of many 

 memoirs, whilst those treating of the upper division are, as 

 might be expected, chiefly concerned with the carboniferous 

 strata. It will be convenient to consider recent additions 

 to our knowledge under three heads : to treat, in the first 

 place, of those papers bearing upon the Precambrian rocks ; 

 next, of those which deal with the lower palaeozoic rocks, 

 and finally, of the more numerous ones which are concerned 

 with the upper palaeozoic strata. 



