316 J. E. Teschemacher on the 
of this branch of geological knowledge becomes manifest. “It 
is, therefore, with the greatest satisfaction I observe that 
Messrs. Brongniart, Góppert, Unger, and others, whose talents 
and industry have already conferred such invaluable benefit 
on this study, appear resolved to renew and extend their labors. 
have examined the few specimens which chance has 
thrown in my way, and these are chiefly fossil Filices ; but, 
even in this already well-labored field, there is considerable 
that is new, still to be gleaned, particularly as regards the ex- 
tensive coal-fields of the American continent. The only diffi- 
culty that exists is in obtaining specimens to study. 
The comparison and identity; then, of the fossil flora of this 
continent with that of the European and the Asiatic conti- 
nents, and more particularly of the flora which prevailed during 
the formation of the coal, may be assumed to be points of 
much interest. 
I will take this opportunity to observe that, I feel certain, 
future developments will show highly resinous plants to have 
largely participated in the formation of coal, (these plants 
being also the least nutritious for animals and best adapted 
to the formation of coal,) and also to express my doubt of the 
usually received doctrine that anthracite is a bituminous coal 
altered by heat, notwithstanding the instances adduced. The 
experiments and observations of Prof. Bailey, of West Point, 
are calculated to throw light on this subject ; it is on similar 
observations, made during the last three or four years, that this 
doubt is partially founded. 4 
The number of fossil ferns described by Brongniart, in his 
Histoire des Vegetaux Fossiles, is about two hundred. f 
these, only twelve are from localities in America, and of these 
twelve, three have not yet been described as found in Europe. 
Nor has Unger, in his Synopsis published 1845, increased the 
number. Mr. Lyell, in his Travels in North America, has 
made several additions, and Dr. C. T. Jackson, in his Report 
on the Geology of Rhode Island, has figured several from the 
black shale above the coal at Portsmouth, in that State ; but 
