LIGNITES. 333 



of those daily and visible actions, of which former ones 

 could but have been the antetypes. If the accompa- 

 nying shells are said to be marine, they offer no objec- 

 tion ; when I have shown the difficulty of assigning 

 this exclusive origin, and when also it is remembered 

 that the theory required such a belief, or assertion. 

 And though they were so, the formation of coal in 

 marine sestuaries would explain even this invented 

 difficulty. 



I must therefore conclude, that the more extensive 

 deposits of lignite coal, in whatever position beneath the 

 chalk and above the red marl, have been produced under 

 circumstances analogous to those of the great coal 

 series, while apparently on the margin of a sea or in 

 sestuaries, rather than in inland lakes. But there are 

 no marks of a revolution with succeeding reversed de- 

 posits, as in the case of that series ; and thence an- 

 other explanation of their present position beneath 

 consecutive and parallel strata is required. This, I 

 think, may be sought in what I have already suggested 

 as an explanation of the great depth of the true coal, 

 and of which the proofs have often already appeared. 

 It is that gradual subsidence of land which admitted 

 the sea to rise above any given portion, while the new 

 deposits, in such a case, must have maintained that 

 parallel order, which, under any sudden and perfect 

 revolution, would have been impossible. If, in these 

 greater deposits, there should be local or occasional 

 portions, formed of marine plants or transported ma- 

 terials, they do not affect the general theory, since 

 they are explained in the same manner as the similar 

 ones in the inferior positions. To say that a sub- 

 sequent general elevation of the entire secondary series 

 brought the whole to their present places, is but 

 to make an unnecessary repetition. And more minute 



