XXXU PEOCEEDINGS OF THE GEOLOGICAL SOCIETY. 



surprise in the palseontologist. I think it fair to the authors of these 

 two remarkable communications, to request that no more weight 

 may be placed on their general views than they wish them to carry. 

 At present, it seems that mesozoic vertebral structure has been 

 found deep in palasozoic strata ; but there is still a chance that these 

 strata may be ultimately found to be of less antiquity ; and there is 

 still something to be added to our knowledge of the fossils before 

 we can fully declare the sum of their affinities. 



In England and Wales, fortunately for the progress of our map, 

 there is no difficulty in setthng the boundaries of the Old Eed 

 Series, except in those tracts of Devon and Cornwall where the 

 usually red series of sandstones, shales, and conglomerates is varied 

 by bands of protoxidated sediments, and modified by cleavage and 

 metamorphic action. To this day we are insufficiently informed of 

 the Kmits of the probably small area of the Silurian rocks in the 

 southern parts of this tract. Nor have we an exact determination 

 of the upper limit of the Devonian rocks in contact with the car- 

 boniferous limestone and shale of Barnstaple, though probably the 

 nearly united opinion of Lonsdale, Murchison, Sedgwick, and myself, 

 which leaves the Pilton and Petherwin beds as Devonian, may be 

 regarded as the most general view. It is adopted on the map. 



Among the singular phaenomena which have been ascertained 

 within no long time, touching the geographical ranges of strata, 

 may be mentioned the occurrence below the Tertiary and Cretaceous 

 series at Harwich, of indurated carboniferous shales traversed by 

 slaty cleavage, — part of the subterranean range of the palaeozoics of 

 Worth Devon, or South Wales, and, like them, containing Posidonice. 



A great change v/ill appear on the new map in reference to the 

 Permian deposits, which, according to the labours of Prof. Ramsay 

 and the Government Survey, spread over much larger space in the 

 Midland Counties than was formerly conceded to them. In a sandy 

 and conglomeratic form they are represented as occupying large tracts 

 formerly assigned to the Kew Ped Sandstone. 



If there be still a want of accordance among geologists as to the 

 association of the bone-bed of Aust, — the fossils, according to Egerton, 

 indicating Triassic affinity, while the nature of the matrix perhaps 

 refers them to the Lias, — this does not affect our map. A point of 

 some difficulty occurs at the upper boundary of the Lias, where the 

 thick and peculiar sands which occur near Bath present affinities 

 in two directions — upwards to the Oolite, downwards to the Lias. 

 We have thought it best to preserve the sands in their ancient 

 geograpliical allegiance to the Oolite, on the map ; but we do not 

 intend by this to pronounce on the value of the evidence of the 

 Cephalopoda and other fossils which has been of late collected, and 

 is still under consideration, by Prof. Buckman, Dr. Wright, and the 

 palaeontologists of Gloucestershire. 



Two observations which have been communicated to the Society 

 during the last session show how very far beyond their actual boun- 

 daries some of the mesozoic strata, composed of fine sediments, for- 

 merly extended. Mr. Jameson has made us acquainted with the 



