PROCEEDINGS OF GEOLOGICAL SOCIETIES. 



207 



shales and clays umderlying these sands form the " Wadhurst Clay" of the 

 author, and are' at places'one hundred and sixty feet thick. This subdivision 

 has yielded much ironstone in former times. It is underlaid by other sand and 

 sandstones, more than two hundred and fifty feet thick, also yielding ironstone. 

 These are termed "Ashdown Sand" by Mr.' Drew, on account of then forming 

 the heights of Ashdown Forest. 



East ward of the meridian of Tunbridge Wells Mr Drew has found the same 

 sequence of beds, and he believes a similar succession to occur around Battle 

 and Hastings. Westward of Tunbridge Wells, as far as East Grinstead the 

 same beds occur, but beyond that the Weald Clay and Tunbridge Wells sand 

 alone are exposed; and the latter is here divided into upper and lower 

 beds by shale and clay (termed "Grinstead Clay" by the author), which 

 thicken westward to fifty feet and more. It is the " Lower Tunbridge Wells 

 Sand" that forms natural rocks near Grinstead. Near Horsham the Weald 

 Clay contains, at about one hundred and twenty feet from its base, bands of 

 stoiie known as the " Horsham Stone," used for roofing and paving. 



The author then explained at large the grounds on which he proposed to 

 replace Dr. Mantell's term " Horsted Sands" by " Upper Tunbridge Wells 

 Sand," that of " Worth Sands," by " Lower Tunbridge Wells Sand," and that 

 of "Tilgate Beds" by " Wadhurst Clay" ; and his reason for proposing the 

 name of Ashdown" for the next lowest bed of the "Hastings Sand." 



The paper concluded with a description of some of the chief lithological 

 characters of the clays and sandstones of the Wealden area under notice. 



2. " On the Permian Rocks of the South of Yorkshire ; and on their 

 Palseontological Relations." By J. W. Kirkby, Esq. Communicated by T. 

 Davidson, Esq., E.G.S. 



The author, after defining the area to be treated of, first noticed the results 

 of the labours of former observers in this district; and then succinctly described 

 the several strata, referring to Professor Sedgwick's Memoir on the Magnesian 

 Limestone for descriptions of the physical geography, and very much of the 

 lithological character of the country under notice. The strata treated of Mr. 

 Kirkby recognizes (in descending order) as 1, the Banter Schiefer, about fifty 

 feet thick ; 2, the Brotherton Beds, one hundred and fifty feet ; 3, the small- 

 grained Dolomite, two hundred and fifty feet ; 4, the Lower Limestone, one 

 hundred and fifty feet ; 5, the Rothliegendes or Lower Red Sandstone, one 

 hundred feet. These were then compared and co-ordinated with the Permian 

 strata of Durham, where the three limestone members are thus represented : — 

 1. The Upper Limestone by the Yellow, Concretionary, and Crystalline Lime- 

 stone (two hundred and fifty feet). 2. The Middle Limestone by the Shell- 

 and Cellular Limestone (two hundred feet) and 3. The Lower Limestone by 

 the Compact Limestone (two hundred feet) and the Marl-slate (ten feet). The 

 over- and under-lying sandstones being much alike as to thickness in the two 

 areas. 



After some remarks on the probable geographical conditions existing in the 

 Permian epoch, the author proceeded to treat of the Permian fossils of South 

 Yorkshire in detail. These belong to about thirty species, and ar^ nearly all 

 from the Lower Limestone ; three species only occurring in the *rotherton 

 beds. With three exceptions they occur also in the several limestones of 

 Durham ; five of them are found in the lower part of the red marls of Lanca- 

 shire ; and six of them are found at Cultra and Tullyconnel in Ireland. The 

 distribution of the species in the several beds at different localities having been 

 fully treated of, the Permian fossils of South Yorkshire were compared ; first, 

 with those of Durham ; next, with those of Lancashire ; and thirdly, with those of 

 Ireland. Remarks on the distribution of the Permian Eauna in time concluded 

 the paper. 



