Fucoidian Epoch. 8^ 



among the amphigenous cryptogams, with Algae, some of which 

 are doubtful ; among the Acrogenous cryptogams, with ferns ; 

 the Monoctyledons are here represented by two species of 

 palms ; the Gymnospermous dicotyledons by the cycadese and 

 coniferse ; the Angiospermous dicotyledons by a species of 

 Acerineee, a betulaceae, a cupulifera, salicineae, an acerineoe, and 

 a juglandea? ; lastly, a few dicotyledons remain, but the de- 

 termination of the families to which they belong is uncertain. 



" We ought, moreover, to notice at least from ten to twelve 

 species of dicotyledonous leaves, indeterminate, and often 

 imperfect, figured by Geinitz, Reuss, Corda, and Goeppert, or 

 existing in collections. 



" This Flora, which contains from sixty to seventy species, 

 is, as we perceive, remarkable in this respect, that the Angios- 

 permous dicotyledons nearly equal the Gymnospermous di- 

 cotyledons, and in the existence of a pretty considerable 

 number of well characterised Cycadese, which cease to appear 

 at the Eocene epoch of the Tertiary formations. 



" The genus Credneria, containing dicotyledonous leaves, 

 with a very peculiar nervation, but the affinities of which are 

 doubtful, is likewise one of the characteristic forms of this 

 epoch, in a pretty considerable number of localities. With 

 regard to the species of dicotyledonous leaves, referred to 

 determined families, I may remark that these supposed rela- 

 tions, founded on very imperfect specimens, and very few in 

 number, are still very uncertain, and incapable of furnishing 

 a basis for comparison with the other Floras, nor any certain 

 conclusion. 



" 3g?, Fucoidian Epoch. — This epoch, which seems to me to 

 form the most natural limit between the Cretaceous and Ter- 

 tiary periods, is characterised by those deposits, so rich in 

 Algae, of a very peculiar form, that they have been called the 

 sandstones or macignos a fucoides, or the flysch of Switzer- 

 land, — a formation very widely spread, especially in southern 

 Europe, from the Pyrenees, as far as the vicinity of Vienna, 

 and even to the Crimea. 



" I have not hitherto found land plants mingled with these 

 marine species. I do not believe that fossil woods have been 

 met with. 



f2 



