Cretaceous Period. 81 



Jurassic period. Here have been found only marine plants, 

 wood, and branches of Coniferse. 



" 2d, In the chloriteous chalk or greensand of southern 

 England, the neighbourhood of Beauvais and Maus ; only 

 Cycadese and marine plants have been observed there. 



*' Zd, In the same formation in Scania, v^^here M. Nilson 

 has observed leaves of Dicotyledons mixed vv^ith leaves of 

 Cycadites. 



" 4^A, At Niederschoena, neai* Freyberg, in Saxony, beds, 

 analogous to greensand or quadersandstein, containing fossils 

 of considerable variety, Cycadeae, Coniferae, and Dicotyledons, 

 particularly Credneria. 



" bth, In the quadersandstein of Bohemia and Silesia, at 

 Blankenburg, at Teifenfurth, Teschen, &c., where this sand- 

 stone is characterised by the presence of dicotyledonous leaves 

 of the genus Credneria, by Cycadese, and particularly by Coni- 

 ferse of considerable variety, described by M. Corda in Reuss' 

 work on the Chalk of Bohemia. 



" 6M, In France, in the iron sands connected with the 

 green sandstones, near Grand-Pre, in the department of 

 Ardennes, where M. Buvignier has found two fossil vegeta- 

 bles of a very remarkable character, a stalk of an arborescent 

 fern, and a cone previously observed in England in the same 

 formation. 



" But in other places, and in beds belonging to epochs cer- 

 tainly different, this period has presented only marine vege- 

 tables ; such more especially are those fucoidal sandstones 

 or macigno, characterised by Chondrites targionii, aequalis, 

 intricatus, &c., now designated by the name of fucoidal sand- 

 stone or flysch — the geological epoch of which has long been 

 doubtful, but which observers seem to agree in considering 

 as a distinct formation, superior to the chalk, and inferior to 

 the most ancient beds of the Tertiary formations. 



" These fucoidal sandstones form a very distinct epoch, 

 which hitherto appears to be characterised only by marine 

 vegetables, and what, at least in a botanical point of view, 

 would form the line of demarcation between the Cretaceous 

 and Tertiary formations ; for it is remarkable that the fuel 

 found there in such great numbers have little connection with 



VOL. XLIX. NO. XCVII. — JULY 1850. P 



