444 L. Lesquereux—Rocky Mountain Lignitic Formation. 
the Ferns, it is as yet impossible to mark its true affinity. It 
appears already in the Dias, as seen from Geinitz’s description. 
Any how, it is of a character far different from any of those re- 
marked in our Kocene fucoids. From its association with the 
mollusks of deep seas, it is clearly a deep marine species. 
t is as yet too soon to enumerate, even approximately, the 
species of fucoids of the American Eocene. <A few are de- 
made only from these representations. 
and at Black Butte splendid specimens of palmis are mixe 
with dicotyledonous leaves in the shale overlying the ert 
coal; while the bed with Saurian bones and shells, about 1 
alm 
cea 
feature of the scanty flora as yet known from the Arkansas and 
T do not 
tribution in the vegetation of our Kocene is sufficient pre 
that this class of plants had already acquired at that ae ne 
remarkable development. Its origin may be discovered late 
> 
