FOUND AT LENNEL BRAES AND ALLANBANK MILL. 19 
worthy of remark. Their external coatings are invariably carbonized. Pro- 
bably their present forms may have been caused by extreme pressure, when 
these vegetables were in a state of decomposition, and subsequently it was 
that foreign substances, by percolation, took possession of the decayed por- 
tions of the plants. It is difficult also to ascertain their height, as they 
have been fractured. The highest stem I have been able to obtain, is not 
much more than four feet, and the lowest part of it about six feet in cir- 
cumference. Owing to the immense superincumbent mass of stratification, 
this part of the research is rendered both tedious and expensive. 
By the above observations, it appears therefore quite clear, that the 
mountain limestone group which to the south of the river Tweed contains 
beds of coal, by no means terminates at or near the ancient boundary of the 
two kingdoms, but approaches within a short distance of the transition range 
of the south of Scotland. It is equally evident, that this unknown extent 
of early vegetation seems to have been called into existence during the for- 
mation of the mountain limestone group, or in the first period of Bronc- 
NIART’s division. Now, according to that gentleman’s opinion, out of six 
classes (with the exception of the marine, and a few uncertain plants), only 
two existed at that period, namely, the Vascular Cryptogamic plants, com- 
prehending the Filices, Equisetacex, and Lycopodiacee, and the Monocoty- 
ledons, containing a small number of plants, which appear to resemble the 
Palms, and arborescent Liliacesz. In fact, M. A. BRoNGNIART states, 
that out of 260 species discovered in this terrain, 220 belong to the vascu- 
lar cryptogamic. 
The existence, therefore, of so extensive a deposit of dicotyledonous 
or gymnospermous phanerogamic plants, at this early period of the earth’s 
vegetation, appears to demand the attention of the naturalist, and goes far 
to prove the necessity of more minute examination among the dark and 
pathless repositories of an ancient world. 
c 2 
