DISTRIBUTION OF FOSSIL FERNS. 405 
iwation of the Carboniferous strata of the Tran- 
sition Series. 
In strata of the Secondary Series, the absolute 
relative numbers of species of Ferns consi- 
derably diminishes, forming scarcely one third 
the known Flora of these midway periods of 
geological history. (See PI. 1. Figs. .37. 38. 39.) 
In the Tertiary Strata, Ferns appear to bear to 
other vegetables nearly the same proportion as 
*0 the temperate regions of the present Earth. 
leaf stalks have fallen off. In Palms and other arborescent 
^tonocotyledons, the leaves, or Petioles, embrace the stem and 
leave broad transverse scars, or rings, whose longer diameter is 
^'■onzontal. In the case of Ferns alone, with the single excejStion 
Angiopteris, the scars are either elliptic or rhoraboidal, and 
their longer diameter vertical. 
M. Ad. Brongniart (Hist, des Veg. Foss. p. 261, PI. 79. 80.) 
'as described and figured the leaf and stem of an arborescent 
(Anomopteris, Mougeottii) from the variegated sand-stone 
Heilegenberg in the Vosges. Beautiful leaves of this species, 
"''til their capsules of fructification sometimes adhering to the 
P'nnules, abound in the New red sand-stone formation of this 
district. 
M. Cotta has published an interesting Work on fossil Remains 
‘^l ^•''borescent ferns, which occur abundantly in the New red sand- 
®tone of Saxony near Chemnitz. {Dendrolithen. Dresden and 
1832.) These consist chiefly of sections of the Trunks 
many extinct species, sufficiently allied in structure to that of 
''isting arborescent Ferns, to leave little doubt that they are the 
®mains of extinct species of arborescent Plants of this family, 
I grew in Europe at this Period of the Secondary formation. 
G. 
H H 
