224 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Nov. 4, 



For these reasons, I have placed the three English sub-divisions so 

 as to represent the whole mass of the Heidelberg sandstone in the 

 annexed Tabular View. 



Muschelkalk. — This formation being unfortunately absent in Eng- 

 land, I shall not dwell upon it here, referring the reader to Dr. von 

 Leonhard's work. 



It folds in undulating layers around the lower flanks of the Oden- 

 wald, and is traversed by the Neckar near Mosbach. It consists of 

 thin- bedded bluish limestones with partings. It is only locally fos- 

 siliferous, containing, amongst the more common species, the follow- 

 ing: — Avicula socialisy Bronn ; Ceratites nodosus, De Haan; Tere- 

 bratula vulgaris, Brongn.; Encrinites liliiformis, Schloth. Haematite 

 is extensively worked near Wiesbach. 



As this formation has no representative in England, it will be 

 sufficient to state that its proper position, were it present, would be 

 immediately under the Waterstones or Lower Keuper Sandstone. — 

 (See Tabular View.) 



Keuper. — A true parallelism may be traced in the order of succes- 

 sion of the beds of this formation in England and around the flanks 

 of the Odenwald, and is confirmatory of the conclusion at which, 

 with Professor Ramsay and Mr. Howell, I had long since arrived, 

 that the strata of sandstones and marls, with a base frequently 

 brecciated and calcareous, and which are known in the Midland 

 Counties of England as "Waterstones," are to be referred to the 

 " Keuper formation." 



In the Odenwald we find the representatives of these beds, com- 

 posed of brown and grey grits, with shales, altogether reaching about 

 100 feet in thickness. In one place, near Wiesbach, a remarkable bed of 

 calcareous breccia occurs, containing fragments of granite, porphyry, 

 and, what is more remarkable, of Bunter Sandstein. A specimen 

 containing this fragment has been shown me by Dr. von Leonhard. 

 These beds undoubtedly represent our "Waterstones," which may 

 therefore be correctly termed " Lower Keuper Sandstone." 



The occurrence of this breccia in a position corresponding so closely 

 with that of the breccias which in Worcestershire, Staffordshire, and 

 Cheshire introduce the Keuper formation is interesting, as affording 

 evidence of littoral conditions in both countries at the commencement 

 of the Keuper period. These particular pebbles in the Keuper of 

 Wiesbach, derived from the older rocks of the Odenwald, including 

 the Bunter Sandstein, go far, I conceive, to prove unconformity to 

 some extent between the two formations, arising from disturbances, 

 accompanied by denudation, at the close of the Muschelkalk period. 

 Similarly, it may be stated, that in some parts of Central England 

 there are indications of unconformity between the Bunter and Keuper. 

 I particularly refer to the neighbourhood of Ashby-de-la-Zouch, and 

 of the Warwickshire Coal-field. In these districts there is an appa- 

 rent independence or want of connexion between these formations ; 

 the conglomerates of the Bunter appearing and disappearing suddenly 

 without any reference to the position of the Waterstones. And 

 when we consider the long blank in the history of our English rocks, 



