Reviews — Kinahan' s Geology of Ireland. 39 



with the Silurian ; but his section (p. 54) to show the unconformable 

 overlie of the Lower Carboniferous sandstones and shales ( = 01d 

 Eed Sandstone, etc.) is not quite clear, for it is suggestive of a 

 fault between what he there marks as " Old Eed Sandstone," and 

 the Dingle or Glengariff grits. Jukes, it should be observed, 

 thought it expedient to join the Dingle or Glengariff grits to the 

 overlying rocks rather than to the Silurians. 



As even Professor Hull links these beds doubtfully with the 

 Silurians, one would have been glad to have been furnished with 

 sections showing more clearly the actual facts, inasmuch as the 

 question is of much importance in its bearing upon the relations of 

 the Silurian and Old Eed Sandstone, and of the Devonian and 

 Carboniferous strata. 



It may be well to bear in mind that in the south-west of England 

 and South Wales, De la Beche found great difficulty in drawing a 

 hard line between the Silurian and Old Eed Sandstone, while in 

 Gloucestershire and Somersetshire the Old Eed Sandstone passes up 

 most gradually into the Lower Carboniferous Eocks. 



Hence, when Mr. Kinahan includes the Old Eed Sandstone of 

 Ireland in the Carboniferous formation, " because in no place in 

 Ireland has it a defined upper boundary, one group graduating into 

 the other," we feel that, while he may be right in theory, the practice 

 will be found a very inconvenient one, and inconsistent with the 

 classification elsewhere adopted. It is only right to add, what he 

 tells us further on, that "only in Munster and in the hills between 

 Lough Eime and Pomeroy, counties of Fermanagh and Tyrone, is 

 the Old Eed Sandstone at the absolute base of the Carboniferous 

 formation ; as in all other places the rocks so called and described 

 are on different geological horizons, ranging up to the base of the 

 Coal-measures." And he shows that this is due to the repetition of 

 sandstones or " shore-beds " throughout the Lower Carboniferous 

 series. The diagram fig. 5, illustrating the changes from the shore- 

 beds into the Carboniferous Limestone, might, we think, have been 

 drawn a little more naturally, without interfering with its object. 



The following table shows the general grouping of the Carbon- 

 iferous rocks adopted by Mr. Kinahan : — 



f Coal-measures. 



j Carboniferous Slate, including the Coomhoola Grits, and 

 Carboniferous^ the Carboniferous Limestone. 



J Yellow Sandstone ) Lower Carboniferous Sandstone 



(_ Old Eed Sandstone J and Shales. 



The interchange of sedimentary conditions exhibited in this series, 

 forms a very interesting study, and one with which all students of 

 the Devonian rocks must make themselves acquainted, in picturing 

 the physical history of those deposits. 



Detailed accounts of the Coal-measures are given, with records of 

 the organic remains, and of the Coal-seams in the several Coal-fields. 



The Permian rocks are bracketed with the Mesozoic division, and 

 Mr. Kinahan observes that in Ireland all the undoubted Permian 

 rocks seem to be intimately connected with the associated Triassic 



