EOCKS OF BOHEMIA. 601 



not endeavour to synchronize any one British subdivision with 

 an exact equivalent in distant foreign lands." In the case of 

 Bohemia, however, we find so many similarities in both lithological 

 and palseontological characters, occurring consecutively through a 

 series of beds, that we cannot suppose them to be mere coincidences. 

 These similarities are most striking in the beds which yield evidence 

 of having been deposited in deep water. 



I. Commencing with the Precambrian rocks, it is soon remarked 

 that the two unconformable series in Bohemia strongly resemble 

 those which have been named Dimetian and Pebidian by Dr. Hicks 

 in Britain. On referring back to the description of the lithological 

 characters of the lowest group in Bohemia, it will be seen to corre- 

 spond exactly with that given by Dr. Hicks of the St. David's 

 Dimetians. There is no indication of any intermediate group, such 

 as that described in Britain as the Arvonian beds ; but the green ash 

 and hornstone series of Bohemia, constituting etage A, Barr., and, 

 according to Professor Krejci, part of etage B also, is regarded by 

 that geologist in his work on the country as contemporaneous with 

 the Huronian rocks in America. It exactly resembles the Pebidian 

 series of Britain, except in the greater development of the horn- 

 stones. As the Dimetian and Pebidian series of St. David's have 

 been correlated by American and Scandinavian geologists with 

 deposits in their own countries, it is not surprising to find similar 

 formations occupying the same horizons in Bohemia. 



II. The Precambrian rocks, as in Britain, are succeeded by aeon- 

 glomerate series, not differing very much from the upper series of 

 the former in their direction of strike, but nevertheless exhibiting a 

 very marked unconformity. The resemblance between the Harlech 

 beds of St. David's and the base of the Cambrian of Bohemia is 

 surprising ; not only do we meet with the basement conglomerate 

 with large pebbles, easily detached from the matrix, but the yellow 

 grits and the red shales are precisely similar to those beds at St. 

 David's which have yielded fossils. It is too much to expect that 

 these Bohemian beds will be found even tolerably fossiliferous, after 

 the almost exhaustive researches of M. Barrande; but it is not 

 impossible that organisms may^yet be found, and the section by 

 the roadside near the village of Cenkau seems well worth a lengthy 

 search. 



The beds of etage C, or the primordial zone of Barrande, have by 

 many authors been compared to some part of the British series. Sir 

 C. Lyell (Students' Elements, p. 487) correlates the Menevian beds 

 and Lingula Flags with this etage. Dr. Hicks (Geol. Mag. dec. ii. 

 vol. iii. table) places the Menevian beds only on this horizon. The 

 Menevian fauna certainly bears a strong resemblance to the fauna of 

 C, e.g. the occurrence in both of the genera Paracloxides, Cono- 

 coryjohe, Arionellus, Agnostus, &c. I think, for reasons to be given 

 presently, that e'tage C does not represent the whole of the Lingula 

 Mags, if any portion of them. In lithological character its resem- 

 blance to the Menevian beds is very strong. They both seem to 

 have been deposited in deep sea ; one proof of this is given in Lyell's 



