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consolidated beds with beds not conso-lidated.

On the other hand, all the older beds, ornearly all, are consolidated. The fuller’searth found at Rossvvein in Upper Saxony,and a similar bed found on the Old Manmountain, at Coniston , occur to me asexceptions to the rule ; but, in general, theold red sandstone may be considered theearliest formation, which appears uncon-solidated.

As a reason for admitting the igneousorigin of trap rocks, it has been a said, that,“ of all other formations, the degree of“ consolidation decreases together with its“ age, their texture passing from crystal-“ line through the several gradations of sub-“ crystalline, compact, coarse, and lastly“ earthy, while in the trap formation, even“ where it rests on chalk, the crystalline“ texture of the oldest rocks frequently“ recurs.”

I suspect that this distinction is not war-ranted by fact, and that trap rocks are, in

* Geological Transactions, vol. iii. p. 208.