142 
SUIITURBIIAND. 
into numerous thin plates, many of which 
possess the tenuity of the finest writing 
paper, and discover on both sides the most 
beautiful and accurate impressions of leaves, 
with all their ramifications of nerves, ribs, 
and fibres, in the best state of preservation. 
The whole of the schistose body is, in fact, 
nothing but an accumulation of leaves 
closely pressed together, and partially in¬ 
terlaid with a fine alluvial clay. It is also 
worthy of notice, that when you separate 
any of the leaves from the mass, they are 
uniformly of a greyish or brown colour on 
the surface, and black on the opposite side. 
Most of those on the specimens now before 
me are of the common poplar, {populus 
tremiilaj and some of them, in the judg¬ 
ment of an eminent botanical gentleman,* 
appear to be of the populus takkamahaka. 
A few birch and willow leaves are also 
observable, but very small in size : where¬ 
as many of the poplar leaves are upwards 
of three inches in breadth. 
“ Scouting the idea of a subterranean 
* Professor Horiiemann of Copenhagen. 
