Carboniferous Period. 327 
ancient flora; for at the present time these two departments 
of the vegetable kingdom form at least four-fifths of the 
whole living species known. But the families, so few in num- 
ber, existing at this period, absolutely contain many more 
species than they now do, as existing on the surface of Europe. 
Thus the Ferns of the coal-formation in Europe comprehend 
about 250 different species, and all Europe now produces 
only 50 species. 
In like manner, the Gymnosperms, which at the present 
time in Europe comprehend only about 25 species of Coni- 
feree and Ephedree, then contained upwards of 120 species 
of very dissimilar forms. 
These families, existing alone, and much more numerous 
than they now are in the same climates, if we embrace 
the whole carboniferous period, were still more remarkable 
on account of the different forms under which they presented 
themselves. Thus, among the Cryptogams, we remark genera 
of Ferns now completely destroyed, and numerous arborescent 
species: Préles (reeds?) or allied vegetables almost arbor- 
escent; Lycopodiacez, forming gigantic trees, all forms at 
present unknown, either throughout the whole world, or at 
least in the temperate zones. 
Among the vegetables which we classify along with the 
Gymnospermous Dicotyledons the differences are still more 
decided ; for they constitute families completely extinct since 
that period ; such are the Sigillariz, Nceggerathie, and the 
Asterophyllitez. 
The characters of the vegetation during the carboniferous 
period may be thus briefly stated :— 
The complete absence of Angiospermous Dicotyledons: 
The complete, or almost complete, absence of Monocoty- 
ledons : 
The predominance of Acrogenous Cryptogams, unusual 
forms, and such as are now destroyed, in the families of Ferns, 
Lycopodiacex, and Equisetacez : 
The great development of Gymnospermous Dicotyledons, 
but resulting from the existence of families completely de- 
stroyed, not only in the present day, but from the end of this 
period. 
