1820.] Geological Society 301 



measures dip on every side from the circumference to tire Interior 

 of the basin in which they occur. A similar subdivision extends 

 through the coal basins of the forest of Dean and South Wales, a 

 description of which will be next entered upon in conformity with 

 the outline given in the introductory paper, or general view of the 

 several coal fields in the districts bordering on the Severn, of which 

 the Somerset and South Gloucester coal basin form a part ; this 

 paper, containing a general view of these several coal basins, 

 and of the intermediate districts on both sides of the Severn,, 

 together with a coloured map and section of the whole area, was 

 laid before the Geological Society in Nov. 1818. 



A paper, by the Rev. James Yates, of Birmingham, was read, 

 giving " An Account of a Variety of Limestone found in Con- 

 nexion with the Clay Ironstone of Staffordshire." 



This peculiar ironstone has obtained the provincial name of 

 Curl, from its peculiar figure, as consisting of concretions which, 

 when united together, approach more or less to the conical form. 

 From its external shape bearing some resemblance to the leaves 

 of a palm folded over each other, it was formerly conceived to 

 be of vegetable origin ; but the author observes that this opinion 

 is evidently incorrect. The curl is always found in connexion, 

 with the bed of clay ironstone, in the south-east of Staffordshire, 

 which is termed the bottom stone of the new mines. 



The author describes the substance in question, as well as the 

 strata to which it is attached ; it generally is found contiguous 

 to the under surface of the ironstone, and is connected with it 

 by the apex of the cone ; but the author suspects that in some 

 situations it may be above this stratum of ironstone, but still with 

 its apex towards the stratum. 



The curl occurs in large masses, forming . protuberances frora 

 5 to 20 yards in extent, and from four inches to half a yard in 

 thickness. It is firmly attached to the ironstone, and would 

 seem to be of contemporaneous formation. 



The paper was accompanied by specimens. 



March 3. — A letter from M. de la Beche, dated Geneva, was 

 read, informing the Society that he was sending some specimens 

 of alpine rocks, and mentioning that in the Museum of Natural 

 History at Geneva he had found several fossils from the blue has 

 of Havre, in France, which correspond exactly with those of the 

 blue lias at Lyme, in Dorsetshire ; amongst them were vertebrae 

 of the ichthyosaurus (the proteo-saurus of Sir E. Home), which 

 appear to be more rare in the lias of France than in that of 

 England ; but in the former, the remains of a fossil crocodile have 

 been found. 



